Table of Contents

Filed Pursuant to Rule 424(b)(5)
Registration No. 333-237639

CALCULATION OF REGISTRATION FEE

Table of Contents

PROSPECTUS SUPPLEMENT

(To prospectus dated April 10, 2020)

$200,000,000

    5.00% Convertible Senior Notes due 2027

─────────

We are offering $200,000,000 aggregate principal amount of our 5.00% convertible senior notes due 2027. In addition, we have granted the underwriters an option to purchase, for settlement within a period of 13 days from, and including, the date notes are first issued, up to an additional $30,000,000 aggregate principal amount of notes solely to cover over-allotments.

MATURITY; INTEREST

We will pay interest on the notes at an annual rate of 5.00%, payable semi-annually in arrears on June 1 and December 1 of each year, beginning on December 1, 2020. The notes will mature on June 1, 2027, unless earlier repurchased, redeemed or converted.

CONVERSION

Noteholders may convert their notes at their option only in the following circumstances: (1) during any calendar quarter (and only during such calendar quarter) commencing after the calendar quarter ending on September 30, 2020 if the last reported sale price per share of our common stock exceeds 130% of the conversion price for each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter; (2) during the five consecutive business days immediately after any 10 consecutive trading day period (such 10 consecutive trading day period, the “measurement period”) if the trading price per $1,000 principal amount of notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price per share of our common stock on such trading day and the conversion rate on such trading day; (3) upon the occurrence of certain corporate events or distributions on our common stock, as described in this prospectus supplement; (4) if we call such notes for redemption; and (5) at any time from, and including, March 1, 2027 until the close of business on the scheduled trading day immediately before the maturity date. We will settle conversions by paying or delivering, as applicable, cash, shares of our common stock or a combination of cash and shares of our common stock, at our election, based on the applicable conversion rate(s). The initial conversion rate is 61.6095 shares per $1,000 principal amount of notes, which represents an initial conversion price of approximately $16.23 per share, and is subject to adjustment as described in this prospectus supplement. If a “make-whole fundamental change” (as defined in this prospectus supplement) occurs, then we will in certain circumstances increase the conversion rate for a specified period of time.

REDEMPTION AND REPURCHASE

The notes will be redeemable, in whole or in part, at our option at any time, and from time to time, on or after June 6, 2024 and on or before the 50th scheduled trading day immediately before the maturity date, at a cash redemption price equal to the principal amount of the notes to be redeemed, plus accrued and unpaid interest, if any, but only if the last reported sale price per share of our common stock exceeds 130% of the conversion price on (1) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date we send the related redemption notice; and (2) the trading day immediately before the date we send such notice. In addition, calling any note for redemption will constitute a make-whole fundamental change with respect to that note, in which case the conversion rate applicable to the conversion of that note will be increased in certain circumstances if it is converted after it is called for redemption.

If a “fundamental change” (as defined in this prospectus supplement) occurs, then, except as described in this prospectus supplement, noteholders may require us to repurchase their notes at a cash repurchase price equal to the principal amount of the notes to be repurchased, plus accrued and unpaid interest, if any.

CONCURRENT EQUITY OFFERING

Concurrently with this offering, we are offering, through a separate prospectus supplement, 9,433,963 shares of our common stock, plus up to an additional 1,415,094 shares of our common stock that the underwriters of the concurrent equity offering have the option to purchase from us. The completion of this offering is not contingent on the completion of the concurrent equity offering, and the completion of the concurrent equity offering is not contingent on the completion of this offering. Accordingly, you should not assume that the concurrent equity offering will be consummated on the terms described in this prospectus supplement, or at all. This prospectus supplement does not constitute an offer to sell, or the solicitation of an offer to buy, any securities being offered in the concurrent equity offering. See “The Concurrent Equity Offering.”

RANKING

The notes will be our senior, unsecured obligations and will be equal in right of payment with our existing and future senior, unsecured indebtedness, senior in right of payment to our existing and future indebtedness that is expressly subordinated to the notes and effectively subordinated to our existing and future secured indebtedness, to the extent of the value of the collateral securing that indebtedness. The notes will be structurally subordinated to all existing and future indebtedness and other liabilities, including trade payables, and (to the extent we are not a holder thereof) preferred equity, if any, of our subsidiaries.

LISTING; COMMON STOCK

No public market currently exists for the notes, and we do not intend to apply to list the notes on any securities exchange or for quotation on any inter-dealer quotation system. Our common stock is listed on the Nasdaq Global Select Market under the symbol “GOSS.” On May 18, 2020, the last reported sale price of our common stock was $15.02 per share.

An investment in the notes involves risks. See “Risk Factors” beginning on page S-7 of this prospectus supplement and the documents incorporated by reference into this prospectus supplement.

Neither the Securities and Exchange Commission nor any state or foreign securities commission or regulatory authority has approved or disapproved of the notes or the shares of our common stock, if any, issuable upon the conversion of the notes or passed upon the adequacy or accuracy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense.

We expect to deliver the notes in book-entry form through the facilities of The Depository Trust Company on or about May 21, 2020.

Prospectus supplement dated May 18, 2020.

Table of Contents

TABLE OF CONTENTS

Prospectus Supplement

Prospectus

S-i

Table of Contents

About This Prospectus Supplement

This prospectus supplement and the accompanying prospectus dated April 10, 2020 are part of a registration statement that we filed with the Securities and Exchange Commission, or SEC, as a “well-known seasoned issuer” as defined in Rule 405 under the Securities Act of 1933, as amended, using a “shelf” registration process. This prospectus supplement and the accompanying prospectus relate to the offer by us of our 5.00% convertible senior notes due 2027, or the notes, to certain investors. We provide information to you about this offering of notes in two separate documents that are bound together: (1) this prospectus supplement, which describes the specific details regarding this offering; and (2) the accompanying prospectus, which provides general information, some of which may not apply to this offering. Generally, when we refer to this “prospectus,” we are referring to both documents combined. If information in this prospectus supplement is inconsistent with the accompanying prospectus, you should rely on this prospectus supplement. However, if any statement in one of these documents is inconsistent with a statement in another document having a later date—for example, a document incorporated by reference in this prospectus supplement or the accompanying prospectus—the statement in the document having the later date modifies or supersedes the earlier statement as our business, financial condition, results of operations and prospects may have changed since the earlier dates. You should read this prospectus supplement, the accompanying prospectus, the documents and information incorporated by reference in this prospectus supplement and the accompanying prospectus, and any free writing prospectus that we have authorized for use in connection with this offering when making your investment decision. You should also read and consider the information in the documents we have referred you to under the headings “Where You Can Find More Information” and “Information Incorporated by Reference.”

You should rely only on information contained in or incorporated by reference into this prospectus supplement and the accompanying prospectus. We have not, and the underwriters have not, authorized anyone to provide you with information that is different. We are offering to sell and seeking offers to buy shares of our common stock only in jurisdictions where offers and sales are permitted. The information contained in this prospectus supplement, the accompanying prospectus, the documents and information incorporated by reference in this prospectus supplement and the accompanying prospectus, and any free writing prospectus that we have authorized for use in connection with this offering are accurate only as of their respective dates, regardless of the time of delivery of this prospectus supplement or of any sale of our common stock.

When we refer to “Gossamer,” “we,” “our,” “us” and the “Company” in this prospectus supplement, we mean Gossamer Bio, Inc. and its subsidiaries, unless otherwise specified.

This prospectus supplement also includes trademarks, tradenames and service marks that are the property of other organizations. Solely for convenience, trademarks and tradenames referred to in this prospectus supplement appear without the ® and ™ symbols, but those references are not intended to indicate, in any way, that we will not assert, to the fullest extent under applicable law, our rights or that the applicable owner will not assert its rights, to these trademarks and tradenames.

S-ii

S-1

S-2

S-3

S-4

S-5

S-6

Table of Contents

Risk Factors

You should consider carefully the risks described below and discussed under the sections captioned “Risk Factors” contained in our Annual Report on Form 10-K for the year ended December 31, 2019 and our Quarterly Report on Form 10-Q for the quarter ended March 31, 2020, as updated by our subsequent filings under the Securities Exchange Act of 1934, as amended, or the Exchange Act, which are incorporated by reference in this prospectus supplement and the accompanying prospectus in their entirety, together with other information in this prospectus supplement, the accompanying prospectus and the information and documents incorporated by reference in this prospectus supplement and the accompanying prospectus, and any free writing prospectus that we have authorized for use in connection with this offering before you make a decision to invest in the notes. If any of the following events actually occur, our business, operating results, prospects or financial condition could be materially and adversely affected. This could cause the trading price of our common stock to decline and you may lose all or part of your investment. The risks described below are not the only ones that we face. Additional risks not presently known to us or that we currently deem immaterial may also affect our business operations.

Risks Relating to Recent Developments in Our Business

Our business is subject to risks arising from epidemic diseases, such as the recent COVID-19 pandemic.

The current COVID-19 worldwide pandemic has presented substantial public health and economic challenges and is affecting our employees, patients, communities and business operations, as well as the U.S. and global economies and financial markets. International and U.S. governmental authorities in impacted regions are taking actions in an effort to slow the spread of COVID-19, including issuing varying forms of “stay-at-home” orders, and restricting business functions outside of one’s home. In response, we have implemented a work-from-home policy for certain of our employees, following the guidelines or directives issued by federal, state and local government agencies in the U.S. To date, we have been able to continue to supply our product candidates to our patients currently enrolled in our clinical trials, including our Phase 2 clinical trials of GB001 and Phase 1/2 clinical trial of GB1275, and do not currently anticipate any interruptions in supply. For our ongoing trials of GB001, we have implemented virtual study visits, direct-to-patient drug supply and remote monitoring. We cannot predict the impact, if any, that such changes to the GB001 trials will have on our planned discussions with global regulatory authorities and potential Phase 3 clinical development. In addition, while we are continuing the clinical trials we have underway in sites across the globe, COVID-19 precautions have delayed, such as the pause in enrollment in our Phase 1b clinical trial for GB002 in PAH, and may continue to delay completion of our current and future trials and may directly or indirectly impact the timeline for data readouts, initiation of, as well as monitoring, data collection and analysis and other related activities for, some of our current and future clinical trials. For example, our current expectations for when we will initiate and how we will enroll our planned Phase 2 clinical trials of GB002 and GB004 are based on an assumption that clinical trial and healthcare activities begin to return to normal and clinical sites reopen by the second half of 2020. In particular with respect to GB002, PAH clinical trial sites are currently closed as PAH patients may be at a higher risk of COVID-19 complications than the general population. Therefore, our assumptions around initiation timing may prove to be incorrect, in particular if COVID-19 continues to spread. As the COVID-19 pandemic continues to spread around the globe, we may experience disruptions that could severely impact our business, clinical trials and manufacturing and supply chains, including:

S-7

Table of Contents

In addition, the spread of COVID-19 has had and may continue to severely impact the trading price of shares of our common stock and could impact our ability to raise additional capital on a timely basis or at all. The COVID-19 pandemic continues to rapidly evolve. The extent to which the COVID-19 may impact our business, including our clinical trials, preclinical research, manufacturing and supply chains and financial condition will depend on future developments, which are highly uncertain and cannot be predicted with confidence, such as the geographic spread of the disease, the duration of the pandemic, travel restrictions and social distancing in the United States and other countries, business closures or business disruptions and the effectiveness of actions taken in the United States and other countries to contain and treat the disease. To the extent the COVID-19 pandemic adversely affects our business and financial results, it may also have the effect of heightening many of the other risks described in this section and in the “Risk Factors” section of our 2019 Annual Report on Form 10-K.

Interim, topline and preliminary data from our clinical trials that we announce or publish from time to time, including our interim analysis for our LEDA Phase 2b clinical trial for GB001, may change as more patient data become available and are subject to audit and verification procedures that could result in material changes in the final data, or cause us not to proceed into Phase 3 clinical development for GB001.  

From time to time, we may publicly disclose preliminary or topline or data from our clinical studies, including our interim analysis for our LEDA Phase 2b clinical trial for GB001 and topline data from our Phase 1b study of GB004, which is based on a preliminary analysis of then-available data, and the results and related findings and conclusions are subject to change following a more comprehensive review of the data related to the particular study or trial. We also make assumptions, estimations, calculations and conclusions as part of our analyses of data, and we may not have received or had the opportunity to fully and carefully evaluate all data. As a result, the topline results that we report may differ from future results of the same studies, or different conclusions or considerations

S-8

Table of Contents

may qualify such results, once additional data have been received and fully evaluated. Topline data also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary data we previously published. As a result, topline data should be viewed with caution until the final data are available. From time to time, we may also disclose interim data from our clinical studies. Interim data from clinical trials that we may complete are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available. Adverse differences between preliminary or interim data and final data could significantly harm our business prospects. In May 2020 we completed a pre-specified interim analysis for our LEDA Phase 2b clinical trial for GB001 in moderate-to-severe eosinophilic asthma, after approximately two thirds of trial participants completed the study. The IDMC reviewed data from the interim analysis of the study and recommended continuation of the study to its completion without modification.  Based on the results of the interim analysis and the IDMC recommendation, we have commenced initial Phase 3 planning and supportive activities in anticipation of completion of the study and final analysis of the study data. We expect to report topline data from the trial in the second half of 2020. Our final decision to proceed to Phase 3 will be determined based on the totality of the final data from the trial, as well as discussions with global regulatory authorities. If the final data from LEDA trial materially differs in an adverse manner from the interim analysis, we may later determine not to proceed into Phase 3 clinical development for this reason or based on final data not warranting continued development or based on other development and commercial assessments of GB001 at that time. In addition, in May 2020 we reported promising topline results from our Phase 1b study of GB004 in patients with active mild-to-moderate UC, and further analysis of such data could result in material changes to the data and our conclusions about this product candidate.

Further, others, including regulatory agencies, may not accept or agree with our assumptions, estimates, calculations, conclusions or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular program, the approvability or commercialization of the particular product candidate or product and our company in general. In addition, the information we choose to publicly disclose regarding a particular study or clinical trial is based on what is typically extensive information, and others may not agree with what we determine is the material or otherwise appropriate information to include in our disclosure, and any information we determine not to disclose may ultimately be deemed significant with respect to future decisions, conclusions, views, activities or otherwise regarding a particular drug, drug candidate or our business. If the topline data that we report differ from actual results, or if others, including regulatory authorities, disagree with the conclusions reached, our ability to obtain approval for, and commercialize, our product candidates may be harmed, which could harm our business, results of operations, prospects or financial condition.

Clinical drug development involves a lengthy and expensive process with an uncertain outcome, and the results of preclinical studies and early clinical trials are not necessarily predictive of future results. In addition, our assumptions about why our product candidates are worthy of future development and potential approval are based on data primarily collected by other companies. Our product candidates may not have favorable results in later clinical trials, if any, or receive regulatory approval on a timely basis, if at all.

Clinical drug development is expensive and can take many years to complete, and its outcome is inherently uncertain. We cannot guarantee that any clinical trials will be conducted as planned or completed on schedule, if at all, and failure can occur at any time during the preclinical study or clinical trial process. Despite promising preclinical or clinical results, any product candidate can unexpectedly fail at any stage of preclinical or clinical development. The historical failure rate for product candidates in our industry is high.

The results from preclinical studies or clinical trials of a product candidate or a competitor’s product candidate in the same class may not predict the results of later clinical trials of our product candidates, and interim results of a clinical trial are not necessarily indicative of final results. Product candidates in later stages of clinical trials may fail to show the desired safety and efficacy characteristics despite having progressed through preclinical studies and initial clinical trials. In particular, while two Phase 2 clinical trials of GB001 had been conducted prior to our acquisition of GB001 and the IDMC recommended continuation of our LEDA Phase 2b clinical trial, we do not know how GB001 will perform in future clinical trials, including as a result of any differences from targeting a population of more severe asthma subjects with elevated eosinophil counts, as well as other differences in our trial design. Further, GB001 did not meet its primary efficacy endpoint of improvement in FEV1 over 10 weeks in the first Phase 2 clinical trial conducted by Pulmagen Therapeutics (Asthma) Limited, or Pulmagen, and the second Phase 2 clinical trial conducted by Pulmagen and its partner, Teijin, was limited to only Japanese patients. While we

S-9

Table of Contents

have designed our ongoing LEDA Phase 2b trial in a manner intended to address what we believe to be the shortcomings of the first Pulmagen Phase 2 clinical trial, we cannot be certain that such failure was not due to GB001 itself or that the results of our ongoing Phase 2b trial will otherwise be successful in a broader patient population, or that the final results of the LEDA trial will differ from the interim analysis, or not warrant proceeding into Phase 3 development. In addition, in October 2019, Novartis announced that its oral DP2 antagonist, fevipiprant, failed to improve lung function in a pair of Phase 3 clinical trials of patients with moderate asthma, and in December 2019, Novartis announced that the pooled analysis from a pair of pivotal Phase 3 clinical trials of patients with moderate-to-severe asthma did not meet the clinically relevant threshold for reduction in rate of moderate-to-severe exacerbation and that the results did not support further development of fevipiprant in asthma. It is not uncommon to observe results in clinical trials that are unexpected based on preclinical studies and early clinical trials, and many product candidates fail in clinical trials despite very promising early results. For example, our decision to advance GB002 as a potential treatment for PAH is based in part on the efficacy of imatinib (Gleevec), a tyrosine kinase inhibitor with known activity against PDGF and marketed for oncology indications, observed by Novartis in a Phase 3 clinical trial; however, we may not observe similar efficacy in our clinical trials of GB002. Moreover, this and any future preclinical and clinical data may be susceptible to varying interpretations and analyses. A number of companies in the pharmaceutical and biotechnology industries have suffered significant setbacks in clinical development even after achieving promising results in earlier studies. Furthermore, we cannot assure you that our preclinical programs will be able to progress from candidate identification to Phase 1 clinical development.

In addition, Teijin, a third party over which we have no control, has the right to develop and commercialize GB001 in Japan. If serious adverse events or other problems occur during any clinical trials of GB001 conducted by Teijin, the FDA or other regulatory authorities may delay, limit or deny approval of GB001 or require us to conduct additional clinical trials as a condition to marketing approval, which would increase our costs. If we receive FDA approval for GB001 and a new and serious safety issue is identified in clinical trials conducted by Teijin, regulatory authorities may withdraw their approval of the product or otherwise restrict our ability to market and sell GB001. In addition, treating physicians may be less willing to prescribe our product due to concerns over such adverse events, which would limit our ability to commercialize GB001.

In addition, in May 2020 we reported promising topline results from our Phase 1b study of GB004 in patients with active mild-to-moderate UC, and we plan to initiate a Phase 2 trial of GB004 in UC in the second half of 2020. However, the Phase 1b study was not powered to show differences in clinical outcomes, and we may not observe positive efficacy data or safety results in our planned Phase 2 trial, including as a result of using a new oral tablet formulation versus the solution used in the Phase 1b study or different dosage strengths versus the doses used in the Phase 1b study.

For the foregoing reasons, we cannot be certain that our ongoing and planned clinical trials and preclinical studies will be successful. Any safety concerns observed in any one of our clinical trials in our targeted indications could limit the prospects for regulatory approval of our product candidates in those and other indications, which could have a material adverse effect on our business, financial condition and results of operations.

We are involved in securities class action litigation and could be subject in the future to securities class action litigation.

In the past, securities class action litigation has often been brought against a company following a decline in the market price of its securities. This risk is especially relevant for us, because biotechnology and pharmaceutical companies have experienced significant stock price volatility in recent years. On April 3, 2020, we, certain of our executive officers and directors, and the underwriters of our initial public offering, or IPO, were named as defendants in a purported securities class action lawsuit on behalf of all persons who purchased or otherwise acquired our securities between February 8, 2019 and December 13, 2020. The complaint generally alleges that we, and such executive officers and directors and the underwriters of our IPO, made false and/or misleading statements and failed to disclose material adverse facts about our business, operations and prospects. This lawsuit and any future lawsuits to which we may become a party are subject to inherent uncertainties and will likely be expensive and time-consuming to investigate, defend and resolve, and will divert our management’s attention and financial and other resources. The outcome of litigation is necessarily uncertain, and we could be forced to expend significant resources in the defense of this and other suits, and we may not prevail. Any litigation to which we are a party may

S-10

Table of Contents

result in an onerous or unfavorable judgment that may not be reversed upon appeal, or in payments of substantial monetary damages or fines, or we may decide to settle this or other lawsuits on similarly unfavorable terms, which could adversely affect our business, financial condition, results of operations or stock price.  See Item 1. “Legal Proceedings” of our Quarterly Report on Form 10-Q for the quarter ended March 31, 2020 for additional information regarding the class action.

Risks Relating to This Offering

The notes will be effectively subordinated to our existing and future secured indebtedness and structurally subordinated to the liabilities of our subsidiaries.

The notes will be our senior, unsecured obligations and will rank equal in right of payment with our existing and future senior, unsecured indebtedness, senior in right of payment to our existing and future indebtedness that is expressly subordinated to the notes and effectively subordinated to our existing and future secured indebtedness, to the extent of the value of the collateral securing that indebtedness, including all indebtedness under our existing credit facility. In addition, because none of our subsidiaries will guarantee the notes, the notes will be structurally subordinated to all existing and future indebtedness and other liabilities, including trade payables, and (to the extent we are not a holder thereof) preferred equity, if any, of our subsidiaries. As of March 31, 2020, excluding intercompany indebtedness, we, including our subsidiaries, had approximately $65.0 million of indebtedness and other liabilities, including trade payables, of which approximately $28.5 million was secured indebtedness under our existing credit facility that we guarantee. In addition, we have the ability to access an additional $120.0 million of loans under our existing credit facility subject to specified availability periods. The indenture governing the notes will not prohibit us or our other subsidiaries from incurring additional indebtedness, including senior or secured indebtedness, in the future.

If a bankruptcy, liquidation, dissolution, reorganization or similar proceeding occurs with respect to us, then the holders of any of our secured indebtedness may proceed directly against the assets securing that indebtedness. Accordingly, those assets will not be available to satisfy any outstanding amounts under our unsecured indebtedness, including the notes, unless the secured indebtedness is first paid in full. The remaining assets, if any, would then be allocated pro rata among the holders of our senior, unsecured indebtedness, including the notes. There may be insufficient assets to pay all amounts then due.

If a bankruptcy, liquidation, dissolution, reorganization or similar proceeding occurs with respect to any of our subsidiaries, then we, as a direct or indirect common equity owner of that subsidiary (and, accordingly, holders of our indebtedness, including the notes), will be subject to the prior claims of that subsidiary’s creditors, including trade creditors and preferred equity holders. We may never receive any amounts from that subsidiary to satisfy amounts due under the notes.

We conduct a significant amount of our operations through our subsidiaries and will rely significantly on our subsidiaries to make payments under the notes.

We conduct a significant amount of our operations through our subsidiaries. Accordingly, our ability to pay amounts due on the notes may depend on any future cash flows of our subsidiaries and their ability to make distributions to us. None of our subsidiaries has guaranteed or otherwise become obligated with respect to the notes. Furthermore, none of our subsidiaries is under any obligation to make payments to us, and any payments to us would depend on the earnings or financial condition of our subsidiaries and various business considerations. Statutory, contractual or other restrictions may also limit our subsidiaries’ ability to pay dividends or make distributions, loans or advances to us, including restrictions under our existing credit facility. For these reasons, we may not have access to any assets or future cash flows of our subsidiaries to make payments on the notes.

S-11

Table of Contents

Our indebtedness and liabilities could limit the cash flow available for our operations, expose us to risks that could adversely affect our business, financial condition and results of operations and impair our ability to satisfy our obligations under the notes.

As of March 31, 2020, excluding intercompany indebtedness, we, including our subsidiaries, had approximately $65.0 million of indebtedness and other liabilities, including trade payables, of which approximately $28.5 million was secured indebtedness under our existing credit facility that we guarantee. We will incur $200.0 million (or, if the underwriters fully exercise their option to purchase additional notes, $230.0 million) principal amount of additional indebtedness as a result of this offering. We may also incur additional indebtedness to meet future financing needs. Our indebtedness could have significant negative consequences for our security holders and our business, results of operations and financial condition by, among other things:

Our business may not generate sufficient funds, and we may otherwise be unable to maintain sufficient cash reserves, to pay amounts due under our indebtedness, including the notes, and our cash needs may increase in the future. In addition, our existing credit facility contains, and any future indebtedness that we may incur may contain, financial and other restrictive covenants that limit our ability to operate our business, raise capital or make payments under our other indebtedness. If we fail to comply with these covenants or to make payments under our indebtedness when due, then we would be in default under that indebtedness, which could, in turn, result in that and our other indebtedness becoming immediately payable in full. For a description of our outstanding indebtedness, see “Description of Other Indebtedness.”

S-12

Table of Contents

We may be unable to raise the funds necessary to repurchase the notes for cash following a fundamental change, or to pay any cash amounts due upon conversion, and our other indebtedness may limit our ability to repurchase the notes or pay cash upon their conversion.

Noteholders may, subject to a limited exception described in this prospectus supplement, require us to repurchase their notes following a fundamental change at a cash repurchase price generally equal to the principal amount of the notes to be repurchased, plus accrued and unpaid interest, if any. See “Description of Notes—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes.” In addition, upon conversion, we will satisfy part or all of our conversion obligation in cash unless we elect to settle conversions solely in shares of our common stock. We may not have enough available cash or be able to obtain financing at the time we are required to repurchase the notes or pay the cash amounts due upon conversion. In addition, applicable law, regulatory authorities and the agreements governing our other indebtedness may restrict our ability to repurchase the notes or pay the cash amounts due upon conversion including pursuant to our existing credit facility. For example, our credit facility currently prohibits us from repurchasing the notes or paying cash amounts due upon conversion without the consent of the lenders. Our failure to repurchase notes or to pay the cash amounts due upon conversion when required will constitute a default under the indenture. A default under the indenture or the fundamental change itself could also lead to a default under agreements governing our other indebtedness, including our credit facility, which may result in that other indebtedness becoming immediately payable in full. We may not have sufficient funds to satisfy all amounts due under the other indebtedness and the notes.

Not all events that may adversely affect the trading price of the notes and our common stock will result in an adjustment to the conversion rate.

We will adjust the conversion rate of the notes for certain events, including:

See “Description of Notes—Conversion Rights—Conversion Rate Adjustments.” We are not required to adjust the conversion rate for other events, such as third-party tender offers or an issuance of common stock (or securities exercisable for, or convertible into, common stock) for cash, that may adversely affect the trading price of the notes and our common stock. An event may occur that adversely affects the noteholders and the trading price of the notes and the underlying shares of our common stock but that does not result in an adjustment to the conversion rate.

Not all significant restructuring transactions will constitute a fundamental change, in which case you will not have the right to require us to repurchase your notes for cash.

If certain corporate events called “fundamental changes” occur, you will have the right to require us to repurchase your notes for cash. See “Description of Notes—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes.” However, the definition of “fundamental change” is limited to specific corporate events and does not include all events that may adversely affect our financial condition or the trading price of the notes. For example, a leveraged recapitalization, refinancing, restructuring or acquisition by us may not constitute a fundamental change that would require us to repurchase the notes. Nonetheless, these events could significantly increase the amount of our indebtedness, harm our credit rating or adversely affect our capital structure and the trading price of the notes.

S-13

Table of Contents

The increase to the conversion rate resulting from a make-whole fundamental change may not adequately compensate noteholders for the lost option value of their notes. In addition, a variety of transactions that do not constitute a make-whole fundamental change may significantly reduce the option value of the notes without a corresponding increase to the conversion rate.

If certain corporate events that constitute a “make-whole fundamental change” occur, then we will, in certain circumstances, temporarily increase the conversion rate. See “Description of Notes—Conversion Rights—Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change.” The amount of the increase to the conversion rate will depend on the date on which the make-whole fundamental change becomes effective and the applicable “stock price.” While the increase to the conversion rate is designed to compensate noteholders for the lost option value of their notes resulting from a make-whole fundamental change, the increase is only an approximation and may not adequately compensate noteholders for the loss in option value. In addition, if the applicable “stock price” is greater than $100.00 per share or less than $13.25 per share (in each case, subject to adjustment), then we will not increase the conversion rate for the make-whole fundamental change. Moreover, we will not increase the conversion rate pursuant to these provisions to an amount that exceeds 75.4716 shares per $1,000 principal amount of notes, subject to adjustment.

Furthermore, the definition of make-whole fundamental change is limited to certain specific transactions. Accordingly, the make-whole fundamental change provisions of the indenture will not protect noteholders from other transactions that could significantly reduce the option value of the notes. For example, a spin-off or sale of a subsidiary or business division with volatile earnings, or a change in our line of business, could significantly affect the trading characteristics of our common stock and reduce the option value of the notes without constituting a make-whole fundamental change that results in a temporary increase to the conversion rate.

In addition, our obligation to increase the conversion rate in connection with a make-whole fundamental change could be considered a penalty, in which case its enforceability would be subject to general principles of reasonableness and equitable remedies.

There is currently no trading market for the notes. If an active trading market for the notes does not develop, then noteholders may be unable to sell their notes at desired times or prices, or at all.

The notes are a new class of securities for which no market currently exists. We do not intend to apply to list the notes on any securities exchange or for quotation on any inter-dealer quotation system. Although the underwriters have advised us that they intend to make a market in the notes, they are not obligated to do so and may discontinue any market-making activity at any time and without notice. Accordingly, an active market for the notes may never develop, and, even if one develops, it may not be maintained. If an active trading market for the notes does not develop or is not maintained, then the market price and liquidity of the notes will be adversely affected and noteholders may not be able to sell their notes at desired times or prices, or at all.

The liquidity of the trading market, if any, and future trading prices of the notes will depend on many factors, including, among other things, the trading price and volatility of our common stock, prevailing interest rates, our dividend yield, financial condition, results of operations, business, prospects and credit quality relative to our competitors, the market for similar securities and the overall securities market. Many of these factors are beyond our control. Historically, the market for convertible debt has been volatile. Market volatility could significantly harm the market for the notes, regardless of our financial condition, results of operations, business, prospects or credit quality.

The trading price of our common stock, the condition of the financial markets, prevailing interest rates and other factors could significantly affect the trading price of the notes.

We expect that the trading price of our common stock will significantly affect the trading price of the notes, which could result in greater volatility in the trading price of the notes than would be expected for non-convertible securities. The trading price of our common stock will likely continue to fluctuate in response to the factors described or referred to elsewhere in this section and under the caption “Cautionary Note Regarding Forward-Looking Statements,” among others, many of which are beyond our control.

S-14

Table of Contents

In addition, the condition of the financial markets and changes in prevailing interest rates can have an adverse effect on the trading price of the notes. For example, prevailing interest rates have fluctuated in the past and are likely to fluctuate in the future, and we would expect an increase in prevailing interest rates to depress the trading price of the notes.

The issuance or sale of shares of our common stock, or rights to acquire shares of our common stock, could depress the trading price of our common stock and the notes.

We may conduct future offerings of our common stock, preferred stock or other securities that are convertible into or exercisable for our common stock to finance our operations or fund acquisitions, or for other purposes. The indenture for the notes will not restrict our ability to issue additional equity securities in the future. If we issue additional shares of our common stock or rights to acquire shares of our common stock, if any of our existing stockholders sells a substantial amount of our common stock, or if the market perceives that such issuances or sales may occur, then the trading price of our common stock, and, accordingly, the notes may significantly decline. In addition, our issuance of additional shares of common stock will dilute the ownership interests of our existing common stockholders, including noteholders who have received shares of our common stock upon conversion of their notes.

We will make only very limited covenants in the indenture, and these limited covenants may not protect your investment.

Many debt instruments contain provisions that are designed to restrict the borrower’s activities and operations in a manner that is designed to preserve the borrower’s ability to make payments on the related indebtedness when due. These provisions include financial and operating covenants, and restrictions on the payments of dividends, the incurrence of indebtedness or the issuance or repurchase of securities by the borrower or any of its subsidiaries. The indenture for the notes will not contain any of these covenants or restrictions or otherwise place any meaningful restrictions on our ability to operate our business as management deems appropriate. As a result, your investment in the notes may not be as protected as an investment in an instrument that contains some or all of these types of covenants and restrictions.

Recent and future regulatory actions, changes in market conditions and other events may adversely affect the trading price and liquidity of the notes and the ability of investors to implement a convertible note arbitrage trading strategy.

We expect that many investors in the notes, including potential purchasers of the notes from investors in this offering, will seek to employ a convertible note arbitrage strategy. Under this strategy, investors typically short sell a certain number of shares of our common stock and adjust their short position over time while they continue to hold the notes. Investors may also implement this type of strategy by entering into swaps on our common stock in lieu of, or in addition to, short selling shares of our common stock.

The SEC and other regulatory authorities have implemented various rules and taken certain actions, and may in the future adopt additional rules and take other actions, that may impact those engaging in short selling activity involving equity securities (including our common stock). These rules and actions include Rule 201 of SEC Regulation SHO, the adoption by the Financial Industry Regulatory Authority, Inc., and the national securities exchanges of a “limit up-limit down” program, the imposition of market-wide circuit breakers that halt trading of securities for certain periods following specific market declines, and the implementation of certain regulatory reforms required by the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010. Any governmental or regulatory action that restricts investors’ ability to effect short sales of our common stock or enter into equity swaps on our common stock could depress the trading price of, and the liquidity of the market for, the notes.

S-15

Table of Contents

In addition, the liquidity of the market for our common stock and other market conditions could deteriorate, which could reduce, or eliminate entirely, the number of shares available for lending in connection with short sale transactions and the number of counterparties willing to enter into an equity swap on our common stock with a note investor. These and other market events could make implementing a convertible note arbitrage strategy prohibitively expensive or infeasible. If investors in this offering or potential purchasers of the notes that seek to employ a convertible note arbitrage strategy are unable to do so on commercial terms, or at all, then the trading price of, and the liquidity of the market for, the notes may significantly decline.

You may be subject to tax if we make or fail to make certain adjustments to the conversion rate of the notes even though you do not receive a corresponding cash distribution.

The conversion rate of the notes is subject to adjustment in certain circumstances, including the payment of cash dividends. If the conversion rate is adjusted as a result of a distribution that is taxable to our common stockholders, such as a cash dividend, you will be deemed to have received a distribution, which may be treated as a dividend subject to U.S. federal income tax, without the receipt of any cash. In addition, a failure to adjust (or to adjust adequately) the conversion rate after an event that increases your proportionate interest in us could be treated as a deemed taxable dividend to you. If a make-whole fundamental change occurs prior to the maturity date, under some circumstances, we will increase the conversion rate for notes converted in connection with the make-whole fundamental change. Such increase also may be treated as a distribution subject to U.S. federal income tax as a dividend. See “Material U.S. Federal Income Tax Considerations.” If you are a non-U.S. holder (as defined under “Material U.S. Federal Income Tax Considerations”), any deemed dividend will generally be subject to U.S. federal withholding tax at a 30% rate, or such lower rate as may be specified by an applicable treaty, which may be set off against subsequent payments on the notes or any shares of our common stock owned by you or from any proceeds of any subsequent sale, exchange or other disposition of the notes (including the retirement of a note) or such common stock or other funds or assets of yours. The Internal Revenue Service has proposed regulations addressing the amount and timing of deemed distributions, obligations of withholding agents and filing and notice obligations of issuers, which if adopted could affect the U.S. federal income tax treatment of beneficial owners of notes deemed to receive such a distribution. See “Material U.S. Federal Income Tax Considerations.”

A rating agency may not rate the notes or may assign a rating that is lower than expected.

We do not intend to seek to have the notes rated by any rating agency. However, if one or more rating agencies rate the notes and assign a rating that is lower than the rating that investors expect, or reduce their rating in the future, then the trading price of our common stock and the notes could significantly decline.

In addition, market perceptions of our creditworthiness will directly affect the trading price of the notes. Accordingly, if a ratings agency rates any of our indebtedness in the future or downgrades or withdraws the rating, or puts us on credit watch, then the trading price of the notes will likely decline.

Provisions in the indenture could delay or prevent an otherwise beneficial takeover of us.

Certain provisions in the notes and the indenture could make a third party attempt to acquire us more difficult or expensive. For example, if a takeover constitutes a fundamental change, then noteholders will have the right to require us to repurchase their notes for cash. In addition, if a takeover constitutes a make-whole fundamental change, then we may be required to temporarily increase the conversion rate. In either case, and in other cases, our obligations under the notes and the indenture could increase the cost of acquiring us or otherwise discourage a third party from acquiring us or removing incumbent management, including in a transaction that noteholders or holders of our common stock may view as favorable.

You may be unable to convert your notes before March 1, 2027, and the trading price of the notes could be less than the value of the consideration into which they could otherwise be converted.

Before March 1, 2027, you may convert your notes only if specific conditions are met. If these conditions are not met, then you will not be able to convert your notes and receive the cash, shares of our common stock or combination of cash and shares, as applicable, into which the notes would otherwise be convertible. As a result, the notes may trade at prices that are less than the value of the consideration into which they would otherwise be convertible.

S-16

Table of Contents

Fluctuations in the trading price of our common stock after you elect to convert your notes may cause you to receive less valuable consideration than expected.

We will generally have the right to settle conversions in cash, shares of our common stock or a combination of cash and shares. If we elect to settle conversions solely in cash or in a combination of cash and shares, then the consideration due upon conversion will be determined based on the volume-weighted average price of our common stock during the related “observation period,” which is defined under the caption “Description of Notes—Definitions” and will consist of 50 consecutive “VWAP trading days.” Except in certain circumstances, the observation period will begin after the related conversion date. Accordingly, a considerable amount of time may lapse between the time you elect to convert your notes and the time you receive the consideration due upon conversion, and if the trading price of our common stock declines during this time, then you may receive less consideration, or consideration that is less valuable, than expected.

Your investment in the notes may be harmed if we redeem the notes.

We will have the right to redeem notes, in whole or in part, in certain circumstances on or after June 6, 2024. See “Description of Notes—Optional Redemption.” If we redeem your notes, then you may not be entitled to benefit from potential future appreciation in the trading price of our common stock, and you may be unable to reinvest any proceeds from the redemption in comparable investments at favorable interest rates. In addition, a redemption of less than all of the outstanding notes will likely harm the liquidity of the market for the unredeemed notes following the redemption. Accordingly, if your notes are not redeemed in a partial redemption, then you may be unable to sell your notes at the times you desire or at favorable prices, if at all, and the trading price of your notes may decline.

Our management may spend the proceeds of this offering in ways with which you may disagree or that may not be profitable.

We intend to use the net proceeds from this offering and, if it is consummated, the concurrent equity offering to fund research and development of our product candidates and development programs and for working capital and general corporate purposes. However, our management will have broad discretion to apply the net proceeds, and investors will rely on our management’s judgment in spending the net proceeds. Our management may use the proceeds in ways that do not earn a profit or otherwise result in the creation of stockholder value.

The accounting method for the notes could adversely affect our reported financial condition and results.

The accounting method for reflecting the notes on our balance sheet, accruing interest expense for the notes and reflecting the underlying shares of our common stock in our reported diluted earnings per share may adversely affect our reported earnings and financial condition.

We expect that, under applicable accounting principles, the initial liability carrying amount of the notes will be the fair value of a similar debt instrument that does not have a conversion feature, valued using our cost of capital for straight, unconvertible debt. We expect to reflect the difference between the net proceeds from this offering and the initial carrying amount as a debt discount for accounting purposes, which will be amortized into interest expense over the term of the notes. As a result of this amortization, the interest expense that we expect to recognize for the notes for accounting purposes will be greater than the cash interest payments we will pay on the notes, which will result in lower reported income or higher reported loss. The lower reported income or higher reported loss resulting from this accounting treatment could depress the trading price of our common stock and the notes.

In addition, we may be eligible to use the treasury stock method to reflect the shares underlying the notes in our diluted earnings per share. Under this method, if the conversion value of the notes exceeds their principal amount for a reporting period, then we will calculate our diluted earnings per share assuming that all the notes were converted and that we issued shares of our common stock to settle the excess. However, if reflecting the notes in diluted earnings per share in this manner is anti-dilutive, or if the conversion value of the notes does not exceed their principal amount for a reporting period, then the shares underlying the notes will not be reflected in our diluted earnings per share. In addition, if accounting standards change in the future and we are not permitted to use the

S-17

Table of Contents

treasury stock method, then our diluted earnings per share may decline. For example, in July 2019, the Financial Accounting Standards Board published an exposure draft proposing to amend these accounting standards to eliminate the treasury stock method for convertible instruments and instead require application of the “if-converted” method. Under that method, if it is adopted, diluted earnings per share would generally be calculated assuming that all the notes were converted solely into shares of common stock at the beginning of the reporting period, unless the result would be anti-dilutive. The application of the if-converted method may reduce our reported diluted earnings per share.

Furthermore, if any of the conditions to the convertibility of the notes is satisfied, then we may be required under applicable accounting standards to reclassify the liability carrying value of the notes as a current, rather than a long-term, liability. This reclassification could be required even if no noteholders convert their notes and could materially reduce our reported working capital.

Because the notes will initially be held in book-entry form, holders must rely on DTC’s procedures to receive communications relating to the notes and exercise their rights and remedies.

We will initially issue the notes in the form of one or more global notes registered in the name of Cede & Co., as nominee of DTC. Beneficial interests in global notes will be shown on, and transfers of global notes will be effected only through, the records maintained by DTC. Except in limited circumstances, we will not issue certificated notes. See “Description of Notes—Book-Entry Procedures for Global Notes” and “Global Securities” in the accompanying prospectus. Accordingly, if you own a beneficial interest in a global note, then you will not be considered an owner or holder of the notes. Instead, DTC or its nominee will be the sole holder of the notes. Unlike persons who have physical notes registered in their names, owners of beneficial interests in global notes will not have the direct right to act on our solicitations for consents or requests for waivers or other actions from holders. Instead, those beneficial owners will be permitted to act only to the extent that they have received appropriate proxies to do so from DTC or, if applicable, a DTC participant. The applicable procedures for the granting of these proxies may not be sufficient to enable owners of beneficial interests in global notes to vote on any requested actions on a timely basis. In addition, notices and other communications relating to the notes (including any notice of redemption) will be sent to DTC. We expect DTC to forward any such communications to DTC participants, which in turn would forward such communications to indirect DTC participants. But we can make no assurances that you timely receive any such communications.

Holding notes will not, in itself, confer any rights with respect to our common stock.

Noteholders will generally not be entitled to any rights with respect to our common stock (including voting rights and rights to receive any dividends or other distributions on our common stock). However, noteholders will be subject to all changes affecting our common stock to the extent the trading price of the notes depends on the market price of our common stock and to the extent they receive shares of our common stock upon conversion of their notes. For example, if we propose an amendment to our charter documents that requires stockholder approval, then a noteholder will not, as such, be entitled to vote on the amendment, although the noteholder will be subject to any changes implemented by that amendment in the powers, preferences or special rights of our common stock.

S-18

Table of Contents

Cautionary Note Regarding Forward-Looking Statements

This prospectus supplement and the accompanying prospectus, including the documents incorporated by reference herein and therein, and any free writing prospectus that we have authorized for use in connection with this offering contain forward-looking statements within the meaning of Section 21E of the Exchange Act. All statements other than statements of historical facts contained in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein are forward-looking statements, including statements regarding: our plans with respect to potential Phase 3 clinical development for GB001; the anticipated timing of initiation and enrollment of clinical trials for our product candidates; plans to advance our product candidates; expectations on the timing of data readouts from our clinical studies; the potential clinical benefits of our product candidates; the expected impact of COVID-19; our future results of operations and financial position, business strategy, prospective products, product approvals, research and development costs, timing and likelihood of success, plans and objectives of management for future operations and future results of product development programs; and the anticipated timing, size, terms and use of proceeds related to this offering and the concurrent equity offering. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. This prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein also contain estimates and other statistical data made by independent parties and by us relating to market size and growth and other data about our industry. This data involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. In addition, projections, assumptions and estimates of our future performance and the future performance of the markets in which we operate are necessarily subject to a high degree of uncertainty and risk.

In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “could,” “intend,” “target,” “project,” “contemplates,” “believes,” “estimates,” “predicts,” “potential” or “continue” or the negative of these terms or other similar expressions. The forward-looking statements in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein are only predictions. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our business, financial condition and results of operations. These forward-looking statements speak only as of the date of this prospectus supplement and are subject to a number of risks, uncertainties and assumptions, which we discuss in greater detail in this prospectus supplement and in the documents incorporated by reference herein, including under the heading “Risk Factors.” The events and circumstances reflected in our forward-looking statements may not be achieved or occur and actual results could differ materially from those projected in the forward-looking statements. Moreover, we operate in an evolving environment. New risk factors and uncertainties may emerge from time to time, and it is not possible for management to predict all risk factors and uncertainties. Given these risks and uncertainties, you should not place undue reliance on these forward-looking statements. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained in this prospectus supplement, the accompanying prospectus or the documents incorporated by reference herein, whether as a result of any new information, future events, changed circumstances or otherwise. For all forward-looking statements, we claim the protection of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995.

S-19

Table of Contents

Use of Proceeds

We estimate that we will receive net proceeds of approximately $193.3 million from the sale of $200.0 million of notes offered by us in this offering, or approximately $222.4 million if the underwriters exercise in full their option to purchase additional notes, after deducting the underwriting discounts and commissions and estimated offering expenses payable by us.

We estimate that we will receive net proceeds of approximately $117.0 million from the concurrent equity offering, if it is consummated, or approximately $134.6 million if the underwriters of the concurrent equity offering exercise in full their option to purchase additional shares of common stock, after deducting the underwriting discounts and commissions and estimated offering expenses payable by us. However, the completion of this offering is not contingent on the completion of the concurrent equity offering, so it is possible that this offering occurs and the concurrent equity offering does not occur or results in lower net proceeds than we currently estimate.

We currently intend to use the net proceeds from this offering and, if it is consummated, from the concurrent equity offering to fund research and development of our product candidates and development programs and for working capital and general corporate purposes.

The amounts and timing of our actual expenditures will depend on numerous factors, including the factors described under “Risk Factors” in this prospectus and in the documents incorporated by reference herein, as well as the amount of cash used in our operations. We may find it necessary or advisable to use the net proceeds for other purposes, and we will have broad discretion in the application of the net proceeds.

Pending the uses described above, we plan to invest the net proceeds from this offering and the net proceeds of the concurrent equity offering, if completed, in short- and intermediate-term, interest-bearing obligations, investment-grade instruments, certificates of deposit or direct or guaranteed obligations of the U.S. government.

S-20

Table of Contents

Capitalization

The following table presents our cash, cash equivalents and marketable securities and our capitalization as of March 31, 2020:

The as adjusted and pro forma as adjusted information in the table below is illustrative only, and our capitalization following the completion of this offering and the concurrent equity offering, if it is completed, will be adjusted based on the final terms of this offering and the concurrent equity offering. Moreover, because the completion of this offering is not contingent on the completion of the concurrent equity offering, you should not assume that the concurrent equity offering, as reflected in the pro forma as adjusted column in the table below, will take place or will take place on the terms assumed in this prospectus supplement.

This table should be read in conjunction with the other information included or incorporated by reference in this prospectus supplement and the accompanying prospectus, including our consolidated financial statements and related notes.

S-21

Table of Contents

The number of shares of our common stock outstanding on an as adjusted and pro forma as adjusted basis is based on 66,338,201 shares outstanding as of March 31, 2020, including 4,243,889 shares subject to forfeiture, and excludes as of that date:

S-22

Table of Contents

Description of Notes

We will issue the notes under an indenture (the “base indenture”), to be dated as of the initial closing date of this offering, between us and Wilmington Trust, National Association, as trustee (the “trustee”), as supplemented by a supplemental indenture (the base indenture, as so supplemented, the “indenture”), to be dated as of the initial closing date of this offering, between us and the trustee.

The following is a summary of certain provisions of the notes and the indenture. It is only a summary and is not complete. We qualify this summary by referring you to the indenture and the notes, because they, and not this summary, define your rights as a holder of the notes. We will provide you with a copy of the indenture, which includes the form of the notes, as provided under the caption “Where You Can Find Additional Information.” In addition, the indenture and the notes will be deemed to include certain terms that are made a part of the indenture and the notes pursuant to the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”).

This “Description of Notes” section supplements and, to the extent inconsistent therewith, supersedes the information in the accompanying prospectus under the caption “Description of Debt Securities.”

Certain terms used in this summary are defined below under the caption “—Definitions.” Certain other terms used in this summary are defined in the indenture.

References to “we,” “us” and “our” in this section refer to Gossamer Bio, Inc. only and not to any of its subsidiaries. References to any “note” in this section refer to any authorized denomination of a note, unless the context requires otherwise.

Generally

The notes will:

S-23

Table of Contents

The indenture will not contain any financial covenants and will not limit us or our subsidiaries from incurring additional indebtedness, paying dividends or issuing or repurchasing any securities. Except to the extent described below under the captions “—Conversion Rights—Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change,” “—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes” and “—Consolidation, Merger and Asset Sale,” the indenture will not contain any provisions designed to protect noteholders upon a highly leveraged transaction involving us or a decline in our credit rating as a result of a recapitalization, takeover, highly leveraged transaction or other restructuring involving us.

Without the consent of any noteholder, we may issue additional notes under the indenture with the same terms as the notes we are offering (except for certain differences, such as the date as of which interest begins to accrue and the first interest payment date for such additional notes). However, such additional notes (and any notes that have been resold after they have been purchased or otherwise acquired by us or our subsidiaries) must be identified by a separate CUSIP number or by no CUSIP number if they are not fungible, for federal income tax or federal securities laws purposes, with other notes we issue under the indenture.

We do not intend to list the notes on any securities exchange or include them in any automated inter-dealer quotation system.

Absent manifest error, a person in whose name a note is registered on the registrar’s books will be considered to be the holder of that note for all purposes, and only registered noteholders (which, in the case of notes held through DTC, will initially be DTC’s nominee, Cede & Co.) will have rights under the indenture as noteholders.

Subject to applicable law, we or our subsidiaries may directly or indirectly repurchase notes in the open market or otherwise, whether through private or public tender or exchange offers, cash-settled swaps or other cash-settled derivatives. Any notes that we or our subsidiaries have purchased or otherwise acquired will be deemed to remain outstanding until such time as we deliver them to the trustee for cancellation. However, subject to the terms of the indenture, notes that we or any of our affiliates own will be disregarded and deemed not to be outstanding for purposes of determining whether the noteholders have concurred in any direction, waiver, consent or other action under the indenture.

Payments on the Notes

We will pay (or cause the paying agent to pay) the principal of, and interest on, any global note by wire transfer of immediately available funds. We will pay (or cause the paying agent to pay) the principal of, and interest on, any physical note as follows:

S-24

Table of Contents

To be timely, a written request referred to in the first bullet point above must be delivered no later than the “close of business” (as defined below under the caption “—Definitions”) on the following date: (i) with respect to the payment of any interest due on an interest payment date, the immediately preceding record date; and (ii) with respect to any other payment, the date that is 15 calendar days immediately before the date such payment is due.

If the due date for a payment on a note is not a “business day” (as defined below under the caption “—Definitions”), then such payment may be made on the immediately following business day and no interest will accrue on such payment as a result of the related delay. Solely for purposes of the immediately preceding sentence, a day on which the applicable place of payment is authorized or required by law or executive order to close or be closed will be deemed not to be a “business day.”

Registrar, Paying Agent and Conversion Agent

We will maintain one or more offices or agencies in the continental United States where notes may be presented for registration of transfer or for exchange, payment and conversion, which we refer to as the “registrar,” “paying agent” and “conversion agent,” respectively. We have appointed trustee as the initial registrar, paying agent and conversion agent and its office in the United States as a place where notes may be presented for payment. However, we may change the registrar, paying agent and conversion agent, and we or any of our subsidiaries may choose to act in that capacity as well, without prior notice to the noteholders.

Transfers and Exchanges

For purposes of the notes, the description below under this section titled “—Transfers and Exchanges” supersedes, in its entirety, the information in the accompanying prospectus under the caption “Transfer and Exchange.”

A noteholder may transfer or exchange its notes at the office of the registrar in accordance with the indenture. We, the trustee and the registrar may require the noteholder to, among other things, deliver appropriate endorsements or transfer instruments, and such certificates or other documentation or evidence as we or they may reasonably require to determine that such transfer or exchange complies with applicable securities laws. In addition, we, the trustee and the registrar may refuse to register the transfer or exchange of any note that is subject to conversion, redemption or required repurchase.

We have appointed the trustee’s corporate trust office in the United States as a place where notes may be presented for registration of transfer or for exchange. However, we may change the registrar or act as the registrar ourselves without prior notice to the noteholders.

Interest

The notes will bear cash interest at an annual rate of 5.00%, payable semi-annually in arrears on June 1 and December 1 of each year, beginning on December 1, 2020, to the noteholders of record of the notes as of the close of business on the immediately preceding May 15 and November 15, respectively. Interest will accrue from, and including, the last date to which interest has been paid or duly provided for (or, if no interest has been paid or duly provided for, from, and including, the date the notes are initially issued) to, but excluding, the next interest payment date. Interest will be computed on the basis of a 360-day year comprised of twelve 30-day months.

In addition to the stated interest on the notes referred to above, special interest will accrue on the notes in the circumstances described below under the caption “—Events of Default—Special Interest as Sole Remedy for Certain Reporting Defaults.” All references in this prospectus supplement to interest on the notes include any special interest payable on the notes, unless the context requires otherwise.

Ranking

The notes will be our senior, unsecured obligations and will be:

S-25

Table of Contents

The indenture will not prohibit us from incurring additional indebtedness, including secured indebtedness, which would be effectively senior to the notes to the extent of the value of the collateral securing that indebtedness, or indebtedness that would rank equal in right of payment with the notes. The indenture will also not prohibit our subsidiaries from incurring any additional indebtedness or other liabilities that would be structurally senior to our obligations under the notes.

In the event of our bankruptcy, liquidation, reorganization or other winding up, our assets that secure any indebtedness will not be available to make payments under the notes unless all of that indebtedness is first paid in full. In the event of the bankruptcy, liquidation, reorganization or other winding up of any of our subsidiaries, we, as a common equity holder of that subsidiary, and, therefore, the noteholders, will rank behind that subsidiary’s creditors, including that subsidiary’s trade creditors, and (to the extent we are not a holder thereof) that subsidiary’s preferred equity holders. Even if we were a creditor of any of our subsidiaries, our rights as a creditor would be effectively subordinated to any security interest of others in the assets of that subsidiary, to the extent of the value of those assets, and would be subordinated to any indebtedness of that subsidiary that is senior in right of payment to that held by us.

Our subsidiaries will have no obligations under the notes. The ability of our subsidiaries to pay dividends or make other payments to us is restricted by, among other things, corporate and other laws and by agreements to which our subsidiaries may become a party, including our existing credit facility. Accordingly, we may be unable to gain access to the cash flow or assets of our subsidiaries to enable us to make payments on the notes.

As of March 31, 2020, excluding intercompany indebtedness, we, including our subsidiaries, had approximately $65.0 million of indebtedness and other liabilities, including trade payables, of which approximately $28.5 million was secured indebtedness under our existing credit facility that we guarantee.

See “Risk Factors—The notes will be effectively subordinated to our existing and future secured indebtedness and structurally subordinated to the liabilities of our subsidiaries.”

Optional Redemption

We may not redeem the notes at our option at any time before June 6, 2024. Subject to the terms of the indenture, we have the right, at our election, to redeem all, or any portion in an authorized denomination, of the notes, at any time, and from time to time, on a redemption date on or after June 6, 2024 and on or before the 50th “scheduled trading day” (as defined below under the caption “—Definitions”) immediately before the maturity date, for cash, but only if the “last reported sale price” (as defined below under the caption “—Definitions”) per share of common stock exceeds 130% of the “conversion price” (as defined below under the caption “—Definitions”) on (i) each of at least 20 “trading days” (as defined below under the caption “—Definitions”), whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date we send the related redemption notice; and (ii) the trading day immediately before the date we send such notice. In addition, calling any note for redemption will constitute a “make-whole fundamental change” (as defined below under the caption “—Definitions”) with respect to that note, in which case the conversion rate applicable to the conversion of that note will be increased in certain circumstances if it is converted after it is called for redemption. If we elect to redeem less than all of the outstanding notes, then the redemption will not constitute a make-whole fundamental change with respect to the notes not called for redemption, and holders of the notes not called for redemption will not be entitled to an increased conversion rate for such notes as described above on account of the redemption, except to the limited extent described further below.

S-26

Table of Contents

The redemption date will be a business day of our choosing that is no more than 75, nor less than 55, scheduled trading days after the date we send the related redemption notice, as described below. However, if, in accordance with the provisions described below under the caption “—Conversion Rights—Settlement upon Conversion—Settlement Method,” we elect to settle all conversions with a conversion date that occurs on or after the date we send such redemption notice and on or before the business day immediately before the related redemption date by physical settlement, then we may instead elect to choose a redemption date that is a business day no more than 60, nor less than 30, calendar days after the date we send such redemption notice.

The redemption price for any note called for redemption will be the principal amount of such note plus accrued and unpaid interest on such note to, but excluding, the redemption date. However, if the redemption date is after a regular record date and on or before the next interest payment date, then (i) the holder of such note at the close of business on such regular record date will be entitled, notwithstanding such redemption, to receive, on or, at our election, before such interest payment date, the unpaid interest that would have accrued on such note to, but excluding, such interest payment date; and (ii) the redemption price will not include accrued and unpaid interest on such note to, but excluding, such redemption date.

We will send to each applicable noteholder notice of the redemption containing certain information set forth in the indenture, including the redemption price and the redemption date.

If only a portion of a note is subject to redemption and that note is converted in part, then the converted portion of that note will be deemed to be from the portion of that note that was subject to redemption.

If we elect to redeem less than all of the outstanding notes, and the holder of any note, or any owner of a beneficial interest in any global note, is reasonably not able to determine, before the close of business on the 52nd scheduled trading day (or, if, as described above, we irrevocably elect physical settlement for all conversions with a conversion date that occurs on or after the date we send the related redemption notice and on or before the business day immediately before the related redemption date, the 10th calendar day) immediately before the relevant redemption date, whether such note or beneficial interest, as applicable, is to be redeemed pursuant to such redemption, then such holder or owner, as applicable, will be entitled to convert such note or beneficial interest, as applicable, at any time before the close of business on the business day immediately before such redemption date, and each such conversion will be deemed to be of a note called for redemption for purposes of the these redemption provisions and the provisions described below under the captions “—Conversion Rights—When the Notes May Be Converted—Conversion upon Redemption” and “—Conversion Rights—Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change.”

Notwithstanding anything to the contrary above, we may not redeem any notes if the principal amount of the notes has been accelerated and such acceleration has not been rescinded on or before the redemption date (including a rescission as a result of the payment of the related redemption price and any related interest described above on the redemption date).

Conversion Rights

Generally

Noteholders will have the right to convert their notes (or any portion of a note in an authorized denomination), in the circumstances described below, into cash, shares of our common stock or a combination of cash and shares of our common stock (together with cash in lieu of any fractional share, if applicable), at our election, based on an initial conversion rate of 61.6095 shares per $1,000 principal amount of notes (which represents an initial conversion price of approximately $16.23 per share).

Noteholders may convert their notes only in the circumstances described below under the caption “—When the Notes May Be Converted.”

S-27

Table of Contents

Treatment of Interest upon Conversion

We will not adjust the conversion rate to account for any accrued and unpaid interest on any note being converted, and, except as described below, our delivery of the consideration due in respect of the conversion will be deemed to fully satisfy and discharge our obligation to pay the principal of, and accrued and unpaid interest, if any, on, such note to, but excluding, the “conversion date” (as defined below under the caption “—Conversion Procedures”). As a result, except as described below, any accrued and unpaid interest on a converted note will be deemed to be paid in full rather than cancelled, extinguished or forfeited. In addition, if the consideration due upon conversion consists of both cash and shares of our common stock, then accrued and unpaid interest that is deemed to be paid therewith will be deemed to be paid first out of such cash.

Notwithstanding anything to the contrary above, if the conversion date of a note is after a regular record date and before the next interest payment date, then:

However, such noteholder need not deliver such cash:

Accordingly, for the avoidance of doubt, all noteholders as of the close of business on the regular record date immediately before the maturity date will receive the full interest payment that would have been due on the maturity date regardless of whether their notes have been converted after such regular record date.

When the Notes May Be Converted

Noteholders may convert their notes only in the circumstances set forth below. However, in no event may notes be converted after the close of business on the scheduled trading day immediately before the maturity date.

Conversion upon Satisfaction of Common Stock Sale Price Condition

A noteholder may convert its notes during any calendar quarter (and only during such calendar quarter) commencing after the calendar quarter ending on September 30, 2020, if the last reported sale price per share of our common stock exceeds 130% of the conversion price for each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter.

S-28

Table of Contents

Conversion upon Satisfaction of Note Trading Price Condition

A noteholder may convert its notes during the five consecutive business days immediately after any 10 consecutive trading day period (such 10 consecutive trading day period, the “measurement period”) if the “trading price” (as defined below under the caption “—Definitions”) per $1,000 principal amount of notes, as determined following a request by a noteholder in accordance with the procedures described below, for each trading day of the measurement period was less than 98% of the product of the last reported sale price per share of our common stock on such trading day and the conversion rate on such trading day. We refer to this condition as the “trading price condition.”

The trading price will be determined by the bid solicitation agent as described below and the definition of “trading price.” The bid solicitation agent (if not us) will have no obligation to solicit the trading price of the notes unless we have requested such solicitation in writing, and we will have no obligation to make such request (or seek bids ourselves) unless a noteholder provides us with reasonable evidence that the trading price per $1,000 principal amount of notes would be less than 98% of the product of the last reported sale price per share of our common stock and the conversion rate. If a noteholder provides such evidence, then we will instruct the bid solicitation agent in writing to (or, if we are acting as the bid solicitation agent, we will) determine the trading price of the notes, in accordance with the bids solicited by the bid solicitation agent, beginning on the next trading day and on each successive trading day until the trading price per $1,000 principal amount of notes is greater than or equal to 98% of the product of the last reported sale price per share of our common stock on such trading day and the conversion rate on such trading day. If the trading price condition has been met as described above, then we will notify the noteholders of the same. If, on any trading day after the trading price condition has been met as described above, the trading price per $1,000 principal amount of notes is greater than or equal to 98% of the product of the last reported sale price per share of our common stock on such trading day and the conversion rate on such trading day, then we will notify the noteholders of the same.

We will act as the initial bid solicitation agent. However, we may change the bid solicitation agent, and we may appoint any of our subsidiaries to act in that capacity as well, without prior notice to the noteholders.

Conversion upon Specified Corporate Events

Certain Distributions

If we elect to:

then, in either case, we will send notice of such distribution, and of the related right to convert notes, to noteholders at least 55 scheduled trading days before the “ex-dividend date” (as defined below under the caption “—Definitions”) for such distribution (or, if later in the case of any such separation of rights issued pursuant to a stockholder rights plan or the occurrence of any such triggering event under a stockholder rights plan, as soon as reasonably practicable after we become aware of that such separation or triggering event has occurred or will occur). However, if we are then otherwise permitted to settle conversions by physical settlement (and, for the avoidance of doubt, we have not elected another settlement method to apply, including pursuant to the provision described in the third sentence under the

S-29

Table of Contents

caption “—Settlement upon Conversion—Settlement Method” below), then we may instead elect to provide such notice at least 10 scheduled trading days before such ex-dividend date. In that event, we will be required to settle all conversions with a conversion date occurring on or after the date we provide such notice and on or before the business day immediately before the ex-dividend date for such distribution (or any earlier announcement by us that such distribution will not take place) by physical settlement, and we will describe the same in the notice. Once we have sent such notice, noteholders may convert their notes at any time until the earlier of the close of business on the business day immediately before such ex-dividend date and our announcement that such distribution will not take place. However, the notes will not become convertible on account of such distribution (but we will still be required to send notice of such distribution as described above) if each noteholder participates, at the same time and on the same terms as holders of our common stock, and solely by virtue of being a noteholder, in such distribution without having to convert such noteholder’s notes and as if such noteholder held a number of shares of our common stock equal to the product of (i) the conversion rate in effect on the record date for such distribution; and (ii) the aggregate principal amount (expressed in thousands) of notes held by such noteholder on such date.

Certain Corporate Events

If a fundamental change, make-whole fundamental change (other than a make-whole fundamental change pursuant to clause (ii) of the definition thereof) or “common stock change event” (as defined below under the caption “—Effect of Common Stock Change Event”) occurs (other than a merger or other business combination transaction that is effected solely for the purpose of changing our jurisdiction of incorporation or an internal reorganization among us and our wholly owned subsidiaries or parent entities (in each case, direct or indirect) such that, following such reorganization, such subsidiaries or parent entities directly or indirectly own 100% of our outstanding equity and, in each case, that (x) does not constitute a fundamental change or a make-whole fundamental change and (y) results in a reclassification, conversion or exchange of outstanding shares of our common stock solely into shares of common stock of the surviving entity and such common stock becomes the “reference property” (as defined below under the caption “—Effect of Common Stock Change Event”) for the notes), then, in each case, noteholders may convert their notes at any time from, and including, the effective date of such transaction or event to, and including, the 35th trading day after such effective date (or, if such transaction or event also constitutes a fundamental change (other than an “exempted fundamental change,” as defined below under the caption “—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes—No Repurchase Right in Certain Circumstances”), to, but excluding, the related fundamental change repurchase date). No later than such effective date, we will send notice to the noteholders of such transaction or event, such effective date and the related right to convert notes. If we do not provide such notice by the effective date, then the last day on which the notes are convertible will be extended by the number of business days from, and including, the effective date to, but excluding, the date we provide the notice.

Conversion upon Redemption

If we call any note for redemption, then the holder of such note may convert such note at any time before the close of business on the business day immediately before the related redemption date (or, if we fail to pay the redemption price due on such redemption date in full, at any time until such time as we pay such redemption price in full).

Conversions During Free Convertibility Period

A noteholder may convert its notes at any time from, and including, March 1, 2027 until the close of business on the scheduled trading day immediately before the maturity date.

Conversion Procedures

To convert a beneficial interest in a global note, the owner of the beneficial interest must:

S-30

Table of Contents

To convert all or a portion of a physical note, the holder of such note must:

Notes may be surrendered for conversion only after the “open of business” (as defined below under the caption “—Definitions”) and before the close of business on a day that is a business day.

We will pay any documentary, stamp or similar issue or transfer tax or duty due on the issue or delivery of any shares of our common stock upon conversion, except any tax or duty that is due because the converting noteholder requests those shares to be registered in a name other than the noteholder’s name.

We refer to the first business day on which the requirements described above to convert a note are satisfied as the “conversion date,” subject to the provision described in the last sentence under the caption “—Settlement upon Conversion—Delivery of the Conversion Consideration.”

If a noteholder has validly delivered a “fundamental change repurchase notice” (as defined below under the caption “—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes”) with respect to a note, then such note may not be converted, except to the extent (i) such notice is withdrawn in accordance with the procedures described below; or (ii) we fail to pay the related fundamental change repurchase price for such note.

Settlement upon Conversion

Generally

Upon conversion, we may choose to pay or deliver, as applicable, either cash (“cash settlement”), shares of our common stock (“physical settlement”) or a combination of cash and shares of our common stock (“combination settlement”), as described below. We refer to each of these settlement methods as a “settlement method.” If cash settlement or combination settlement applies to a conversion, then the consideration due will be determined over an “observation period” (as defined below under the caption “—Definitions”) consisting of 50 “VWAP trading days” (as defined below under the caption “—Definitions”).

Settlement Method

We will have the right, as described below, to elect the settlement method applicable to the conversion of any notes. Except as described below, we must use the same settlement method for all conversions with the same conversion date, but we will not be obligated to use the same settlement method for conversions with different conversion dates. All conversions with a conversion date that occurs on or after March 1, 2027 will be settled using the same settlement method, and we will send notice of such settlement method to noteholders no later than the open of business on March 1, 2027. If we elect a settlement method for a conversion with a conversion date that occurs before March 1, 2027, then we will send notice of such settlement method to the converting noteholder no later than the close of business on the business day immediately after the conversion date. However, as described above under the captions “—Optional Redemption” and “—When the Notes May Be Converted—Conversion upon Specified Corporate Events—Certain Distributions,” we may in certain circumstances elect that physical settlement apply to all conversions with a conversion date occurring during the periods referred to under those captions. Notwithstanding anything to the

S-31

Table of Contents

contrary described above, if we call any notes for redemption, then (i) we will specify in the related redemption notice the settlement method that will apply to all conversions with a conversion date that occurs on or after the date we send such redemption notice and before the related redemption date; and (ii) if the related redemption date is on or after March 1, 2027, then such settlement method must be the same settlement method that applies to all conversions with a conversion date that occurs on or after March 1, 2027.

If we do not timely elect a settlement method with respect to any conversion, then we will be deemed to have elected the “default settlement method” (as defined below). If we timely elect combination settlement with respect to a conversion but do not timely notify the converting noteholder of the applicable “specified dollar amount” (as defined below under the caption “—Definitions”), then the specified dollar amount for such conversion will be deemed to be $1,000 per $1,000 principal amount of notes. For the avoidance of doubt, our failure to timely elect a settlement method or specify the applicable specified dollar amount will not constitute a default under the indenture.

The “default settlement method” will initially be combination settlement with a specified dollar amount of $1,000 per $1,000 principal amount of notes. However, we may, from time to time, change the default settlement method by sending notice of the new default settlement method to the noteholders. In addition, we may, by notice to the noteholders, irrevocably fix the settlement method, to any settlement method that we are then permitted to elect, that will apply to all note conversions with a conversion date that is on or after the date we send such notice. For the avoidance of doubt, such an irrevocable election, if made, will be effective without the need to amend the indenture or the notes, including pursuant to the provisions described in the seventh bullet point of the third paragraph under the caption “—Modification and Amendment” below. However, we may nonetheless choose to execute such an amendment at our option.

Consideration Due upon Conversion

The consideration due upon conversion of each $1,000 principal amount of a note will be as follows:

However, in lieu of delivering any fractional share of common stock otherwise due upon conversion, we will pay cash based on (i) the daily VWAP on the applicable conversion date (or, if such conversion date is not a VWAP trading day, the immediately preceding VWAP trading day), in the case of physical settlement; or (ii) the daily VWAP on the last VWAP trading day of the applicable observation period, in the case of combination settlement.

If a noteholder converts more than one note on a conversion date, then the consideration due upon such conversion will (in the case of any global note, to the extent permitted by, and practicable under, the depositary procedures) be computed based on the total principal amount of notes converted on such conversion date by that noteholder.

Delivery of the Conversion Consideration

Except as described below under the captions “—Conversion Rate Adjustments” and “—Effect of Common Stock Change Event,” we will pay or deliver, as applicable, the consideration due upon conversion as follows: (i) if cash settlement or combination settlement applies, on or before the second business day immediately after the last VWAP trading day of the observation period for such conversion; and (ii) if physical settlement applies, on or before the second business day immediately after the conversion date for such conversion. However, if physical settlement

S-32

Table of Contents

applies to the conversion of any note with a conversion date that is after the regular record date immediately before the maturity date, then, solely for purposes of such conversion, we will pay or deliver, as applicable, the consideration due upon such conversion no later than the maturity date (or, if the maturity date is not a business day, the next business day) and the conversion date will instead be deemed to be the second business day immediately before the maturity date.

When Converting Noteholders Become Stockholders of Record

The person in whose name any share of common stock is issuable upon conversion of any note will be deemed to become the holder of record of that share as of the close of business on (i) the conversion date for such conversion, in the case of physical settlement; or (ii) the last VWAP trading day of the observation period for such conversion, in the case of combination settlement.

Conversion Rate Adjustments

Generally

The conversion rate will be adjusted for the events described below. However, we are not required to adjust the conversion rate for these events (other than a stock split or combination or a tender or exchange offer) if each noteholder participates, at the same time and on the same terms as holders of our common stock, and solely by virtue of being a holder of notes, in such transaction or event without having to convert such noteholder’s notes and as if such noteholder held a number of shares of our common stock equal to the product of (i) the conversion rate in effect on the related record date; and (ii) the aggregate principal amount (expressed in thousands) of notes held by such noteholder on such date.

where:

S-33

Table of Contents

If any dividend, distribution, stock split or stock combination of the type described in this paragraph (1) is declared or announced, but not so paid or made, then the conversion rate will be readjusted, effective as of the date our board of directors determines not to pay such dividend or distribution or to effect such stock split or stock combination, to the conversion rate that would then be in effect had such dividend, distribution, stock split or stock combination not been declared or announced.

where:

To the extent such rights, options or warrants are not so distributed, the conversion rate will be readjusted to the conversion rate that would then be in effect had the increase to the conversion rate for such distribution been made on the basis of only the rights, options or warrants, if any, actually distributed. In addition, to the extent that shares of our common stock are not delivered after the expiration of such rights, options or warrants (including as a result of such rights, options or warrants not being exercised), the conversion rate will be readjusted to the conversion rate that would then be in effect had the increase to the conversion rate for such distribution been made on the basis of delivery of only the number of shares of our common stock actually delivered upon exercise of such rights, option or warrants.

For purposes of this paragraph (2) and the provisions described above under the caption “—When the Notes May Be Converted—Conversion upon Specified Corporate Events—Certain Distributions,” in determining whether any rights, options or warrants entitle holders of our common stock to subscribe for or purchase shares of our common stock at a price per share that is less than the average of the last reported sale prices per share of our common stock for the 10 consecutive trading days ending on, and including, the trading day immediately before the date the distribution of such rights, options or warrants is announced, and in determining the aggregate price payable to exercise such rights, options or warrants, there will be taken into account any consideration we receive for such rights, options or warrants and any amount payable on exercise thereof, with the value of such consideration, if not cash, to be determined by our board of directors.

S-34

Table of Contents

then the conversion rate will be increased based on the following formula:

where:

S-35

Table of Contents

However, if FMV is equal to or greater than SP, then, in lieu of the foregoing adjustment to the conversion rate, each noteholder will receive, for each $1,000 principal amount of notes held by such noteholder on the record date for such distribution, at the same time and on the same terms as holders of our common stock, the amount and kind of shares of capital stock, evidences of indebtedness, assets, property, rights, options or warrants that such noteholder would have received if such noteholder had owned, on such record date, a number of shares of our common stock equal to the conversion rate in effect on such record date.

To the extent such distribution is not so paid or made, the conversion rate will be readjusted to the conversion rate that would then be in effect had the adjustment been made on the basis of only the distribution, if any, actually made or paid.

where:

S-36

Table of Contents

Notwithstanding anything to the contrary, (i) if any VWAP trading day of the observation period for a note whose conversion will be settled pursuant to cash settlement or combination settlement occurs during the spin-off valuation period for such spin-off, then, solely for purposes of determining the conversion rate for such VWAP trading day for such conversion, such spin-off valuation period will be deemed to consist of the trading days occurring in the period from, and including, the ex-dividend date for such spin-off to, and including, such VWAP trading day; and (ii) if the conversion date for a note whose conversion will be settled pursuant to physical settlement occurs during the spin-off valuation period for such spin-off, then, solely for purposes of determining the consideration due in respect of such conversion, such spin-off valuation period will be deemed to consist of the trading days occurring in the period from, and including, the ex-dividend date for such spin-off to, and including, such conversion date.

To the extent any dividend or distribution of the type described above in this paragraph (3)(b) is declared but not made or paid, the conversion rate will be readjusted to the conversion rate that would then be in effect had the adjustment been made on the basis of only the dividend or distribution, if any, actually made or paid.

where:

However, if D is equal to or greater than SP, then, in lieu of the foregoing adjustment to the conversion rate, each noteholder will receive, for each $1,000 principal amount of notes held by such noteholder on the record date for such dividend or distribution, at the same time and on the same terms as holders of our common stock, the amount of cash that such noteholder would have received if such noteholder had owned, on such record date, a number of shares of our common stock equal to the conversion rate in effect on such record date. To the extent such dividend or distribution is declared but not made or paid, the conversion rate will be readjusted to the conversion rate that would then be in effect had the adjustment been made on the basis of only the dividend or distribution, if any, actually made or paid.

S-37

Table of Contents

where:

provided, however, that the conversion rate will in no event be adjusted down pursuant to the provisions described in this paragraph (5), except to the extent provided in the immediately following paragraph. Notwithstanding anything to the contrary, (i) if any VWAP trading day of the observation period for a note whose conversion will be settled pursuant to cash settlement or combination settlement occurs during the tender/exchange offer valuation period for such tender or exchange offer, then, solely for purposes of determining the conversion rate for such VWAP trading day for such conversion, such tender/exchange offer valuation period will be deemed to consist of the trading days occurring in the period from, and including, the trading day immediately after the expiration date for such tender or exchange offer to, and including, such VWAP trading day; and (ii) if the conversion date for a note whose conversion will be settled pursuant to physical settlement occurs during the tender/exchange offer valuation period for such tender or exchange offer, then, solely for purposes of determining the consideration due in respect of such conversion, such tender/exchange offer valuation period will be deemed to consist of the trading days occurring in the period from, and including, the trading day immediately after the expiration date to, and including, such conversion date.

To the extent such tender or exchange offer is announced but not consummated (including as a result of being precluded from consummating such tender or exchange offer under applicable law), or any purchases or exchanges of shares of common stock in such tender or exchange offer are rescinded, the conversion rate will be readjusted to the conversion rate that would then be in effect had the adjustment been made on the basis of only the purchases or exchanges of shares of common stock, if any, actually made, and not rescinded, in such tender or exchange offer.

S-38

Table of Contents

We will not be required to adjust the conversion rate except as described above or below under the caption “—Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change.” Without limiting the foregoing, we will not be required to adjust the conversion rate on account of:

Notice of Conversion Rate Adjustments

Upon the effectiveness of any adjustment to the conversion rate pursuant to the provisions described above under the caption “—Conversion Rate Adjustments—Generally,” we will promptly send notice to the noteholders containing (i) a brief description of the transaction or other event on account of which such adjustment was made; (ii) the conversion rate in effect immediately after such adjustment; and (iii) the effective time of such adjustment.

Voluntary Conversion Rate Increases

To the extent permitted by law and applicable stock exchange rules, we, from time to time, may (but are not required to) increase the conversion rate by any amount if (i) our board of directors determines that such increase is in our best interest or that such increase is advisable to avoid or diminish any income tax imposed on holders of our common stock or rights to purchase our common stock as a result of any dividend or distribution of shares (or rights to acquire shares) of our common stock or any similar event; (ii) such increase is in effect for a period of at least 20 business days; and (iii) such increase is irrevocable during such period.

Tax Considerations

A holder or beneficial owner of the notes may, in some circumstances, including a cash distribution or dividend on our common stock, be deemed to have received a distribution that is subject to U.S. federal income tax as a result of an adjustment or the non-occurrence of an adjustment to the conversion rate. Applicable withholding taxes (including backup withholding) may be withheld from interest and payments upon conversion, repurchase, redemption or maturity of the notes. In addition, if any withholding taxes (including backup withholding) are paid on behalf of a holder or beneficial owner, then those withholding taxes may be withheld from or set off against payments of cash or the delivery of shares of common stock, if any, in respect of the notes (or, in some circumstances, any payments on our common stock) or sales proceeds received by, or other funds or assets of, that holder or beneficial owner. For a discussion of the U.S. federal income tax treatment of an adjustment to the conversion rate, see “Material U.S. Federal Income Tax Considerations.”

S-39

Table of Contents

The Deferral Exception

If an adjustment to the conversion rate otherwise required by the indenture would result in a change of less than 1% to the conversion rate, then we may, at our election, defer such adjustment, except that all such deferred adjustments must be given effect immediately upon the earliest of the following: (i) when all such deferred adjustments would result in a change of at least 1% to the conversion rate; (ii) the conversion date of, or any VWAP trading day of an observation period for, any note; (iii) the date a fundamental change or make-whole fundamental change occurs; (iv) the date we call any notes for redemption; and (v) March 1, 2027. We refer to our ability to defer adjustments as described above as the “deferral exception.”

Special Provisions for Adjustments that Are Not Yet Effective and Where Converting Noteholders Participate in the Relevant Transaction or Event

Notwithstanding anything to the contrary, if:

then, solely for purposes of such conversion, we will, without duplication, give effect to such adjustment on such conversion date (in the case of physical settlement) or such VWAP trading day (in the case of combination settlement). In such case, if the date we are otherwise required to deliver the consideration due upon such conversion is before the first date on which the amount of such adjustment can be determined, then we will delay the settlement of such conversion until the second business day after such first date.

Notwithstanding anything to the contrary, if:

S-40

Table of Contents

then:

Stockholder Rights Plans

If any shares of our common stock are to be issued upon conversion of any note and, at the time of such conversion, we have in effect any stockholder rights plan, then the holder of that note will be entitled to receive, in addition to, and concurrently with the delivery of, the consideration otherwise due upon such conversion, the rights set forth in such stockholder rights plan, unless such rights have separated from our common stock at such time, in which case, and only in such case, the conversion rate will be adjusted pursuant to the provisions described above in paragraph (3)(a) under the caption “—Conversion Rate Adjustments—Generally” on account of such separation as if, at the time of such separation, we had made a distribution of the type referred to in such paragraph to all holders of our common stock, subject to readjustment as described above if such rights expire, terminate or are redeemed. We currently do not have a stockholder rights plan in effect.

Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change

Generally

If a make-whole fundamental change occurs and the conversion date for the conversion of a note occurs during the related “make-whole fundamental change conversion period” (as defined below under the caption “—Definitions”), then, subject to the provisions described below, the conversion rate applicable to such conversion will be increased by a number of shares (the “additional shares”) set forth in the table below corresponding (after interpolation as described below) to the “make-whole fundamental change effective date” (as defined below under the caption “—Definitions”) and the “stock price” (as defined below under the caption “—Definitions”) of such make-whole fundamental change:

S-41

Table of Contents

If such make-whole fundamental change effective date or stock price is not set forth in the table above, then:

Notwithstanding anything to the contrary, in no event will the conversion rate be increased to an amount that exceeds 75.4716 shares of our common stock per $1,000 principal amount of notes, which amount is subject to adjustment in the same manner as, and at the same time and for the same events for which, the conversion rate is required to be adjusted pursuant to the provisions described above under the caption “—Conversion Rate Adjustments—Generally.”

For the avoidance of doubt, calling any notes for redemption will constitute a make-whole fundamental change only with respect to the notes called (or deemed called) for redemption, and not with respect to the notes not called for redemption. Accordingly, if we elect to redeem less than all of the outstanding notes, then holders of the notes not called for redemption will not be entitled to an increased conversion rate for such notes as described above on account of the redemption, except to the limited extent described above under the caption “—Optional Redemption.”

As set forth in the definition of “make-whole fundamental change conversion period” below under the caption “—Definitions,” if the conversion date for the conversion of a note occurs during a make-whole fundamental change conversion period relating to both a make-whole fundamental change resulting from our calling notes for redemption and another make-whole fundamental change, then, solely for purposes of that conversion, such conversion date will be deemed to occur only during the period relating to the make-whole fundamental change with the earlier make-whole fundamental change effective date. In that circumstance, the make-whole fundamental change with the later make-whole fundamental change effective date will be deemed not to occur for purposes of such conversion.

Adjustment of Stock Prices and Number of Additional Shares

The stock prices in the first row (i.e., the column headers) of the table above will be adjusted in the same manner as, and at the same time and for the same events for which, the conversion price is adjusted as a result of the operation of the provisions described above under the caption “—Conversion Rate Adjustments—Generally.” The numbers of additional shares in the table above will be adjusted in the same manner as, and at the same time and for the same events for which, the conversion rate is adjusted pursuant to the provisions described above under the caption “—Conversion Rate Adjustments—Generally.”

Notice of Make-Whole Fundamental Change

We will notify noteholders of each make-whole fundamental change in accordance with the provisions described above under the captions “—When the Notes May Be Converted—Conversion upon Specified Corporate Events—Certain Corporate Events” and “—Optional Redemption.”

Enforceability

Our obligation to increase the conversion rate as described above in connection with a make-whole fundamental change could be considered a penalty, in which case its enforceability would be subject to general principles of reasonableness and equitable remedies.

S-42

Table of Contents

Effect of Common Stock Change Event

Generally

If there occurs any:

and, as a result of which, our common stock is converted into, or is exchanged for, or represents solely the right to receive, other securities, cash or other property, or any combination of the foregoing (such an event, a “common stock change event,” and such other securities, cash or property, the “reference property,” and the amount and kind of reference property that a holder of one share of our common stock would be entitled to receive on account of such common stock change event (without giving effect to any arrangement not to issue or deliver a fractional portion of any security or other property), a “reference property unit”), then, notwithstanding anything to the contrary,

S-43

Table of Contents

If the reference property consists of more than a single type of consideration to be determined based in part upon any form of stockholder election, then the composition of the reference property unit will be deemed to be the weighted average of the types and amounts of consideration actually received, per share of our common stock, by the holders of our common stock. We will notify the noteholders of such weighted average as soon as practicable after such determination is made.

We will not become a party to any common stock change event unless its terms are consistent with the provisions described under this “—Effect of Common Stock Change Event” caption.

Execution of Supplemental Indenture

At or before the effective time of the common stock change event, we and the resulting, surviving or transferee person (if not us) of such common stock change event (the “successor person”) will execute and deliver to the trustee a supplemental indenture that (i) provides for subsequent adjustments to the conversion rate in a manner consistent with the provisions described above; and (ii) contains such other provisions, if any, that we reasonably determine are appropriate to preserve the economic interests of the noteholders and to give effect to the provisions described above. If the reference property includes shares of stock or other securities or assets (other than cash) of a person other than the successor person, then such other person will also execute such supplemental indenture and such supplemental indenture will contain such additional provisions, if any, that we reasonably determine are appropriate to preserve the economic interests of noteholders.

Notice of Common Stock Change Event

We will provide notice of each common stock change event to noteholders no later than the second business day after the effective date of the common stock change event.

Exchange in Lieu of Conversion

Notwithstanding anything to the contrary, and subject to the terms of the indenture, if a note is submitted for conversion, we may elect to arrange to have such note exchanged in lieu of conversion by a financial institution we designate. To make such election, we must send notice of such election to the holder of such note before the close of business on the business day immediately following the conversion date for such note, and we must arrange for the financial institution to deliver the consideration due upon such conversion in the same manner and at the same time as we would have been required to do so. We will remain responsible to deliver such consideration if the financial institution fails to timely deliver the same.

We, the conversion agent and the holders surrendering the notes for conversion shall cooperate to cause such notes to be delivered to the designated financial institution and the conversion agent shall be entitled to conclusively rely on our instruction in connection with effecting any exchange election and shall have no liability for such exchange election outside of its control.

Any notes exchanged by the designated financial institution will remain outstanding, notwithstanding the surrender of such notes and will be subject to the procedures of the depositary.

Equitable Adjustments to Prices

Whenever the indenture requires us to calculate the average of the last reported sale prices, or any function thereof, over a period of multiple days (including to calculate the stock price or an adjustment to the conversion rate), or to calculate daily VWAPs over an observation period, we will make proportionate adjustments to those calculations to account for any adjustment to the conversion rate pursuant to paragraph (1) above under the caption “—Conversion Rights—Conversion Rate Adjustments—Generally” that becomes effective, or any event requiring such an adjustment to the conversion rate where the ex-dividend date or effective date, as applicable, of such event occurs, at any time during such period or observation period, as applicable.

S-44

Table of Contents

Fundamental Change Permits Noteholders to Require Us to Repurchase Notes

For purposes of the notes, the description below under this section titled “—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes” supersedes, in its entirety, the information in the accompanying prospectus under the caption “No Protection in the Event of a Change of Control.”

Generally

If a fundamental change occurs, then each noteholder will have the right (the “fundamental change repurchase right”) to require us to repurchase its notes (or any portion thereof in an authorized denomination) for cash on a date (the “fundamental change repurchase date”) of our choosing, which must be a business day that is no more than 35, nor less than 20, business days after the date we send the related fundamental change notice, as described below.

The repurchase price (the “fundamental change repurchase price”) for a note tendered for repurchase will be the principal amount of such note plus accrued and unpaid interest on such note to, but excluding, the fundamental change repurchase date. However, if the fundamental change repurchase date is after a regular record date and on or before the next interest payment date, then (i) the holder of such note at the close of business on such regular record date will be entitled, notwithstanding such repurchase, to receive, on or, at our election, before such interest payment date, the unpaid interest that would have accrued on such note to, but excluding, such interest payment date; and (ii) the fundamental change repurchase price will not include accrued and unpaid interest on such note to, but excluding, the fundamental change repurchase date.

Notwithstanding anything to the contrary above, we may not repurchase any notes if the principal amount of the notes has been accelerated and such acceleration has not been rescinded on or before the fundamental change repurchase date (including as a result of the payment of the related fundamental change repurchase price and any related interest described above on the fundamental change repurchase date).

Notice of Fundamental Change

On or before the 20th calendar day after the effective date of a fundamental change, we will send to each noteholder notice of such fundamental change containing certain information set forth in the indenture, including the fundamental change repurchase date, the fundamental change repurchase price and the procedures noteholders must follow to tender their notes for repurchase.

Procedures to Exercise the Fundamental Change Repurchase Right

To exercise its fundamental change repurchase right with respect to a note, the holder thereof must deliver a notice (a “fundamental change repurchase notice”) to the paying agent such repurchase before the close of business on the business day immediately before the related fundamental change repurchase date (or such later time as may be required by law).

The fundamental change repurchase notice must contain certain information set forth in the indenture, including the certificate number of any physical notes to be repurchased, or must otherwise comply with the depositary procedures in the case of a global note.

A noteholder that has delivered a fundamental change repurchase notice with respect to a note may withdraw that notice by delivering a withdrawal notice to the paying agent at any time before the close of business on the business day immediately before the fundamental change repurchase date. The withdrawal notice must contain certain information set forth in the indenture, including the certificate number of any physical notes with respect to which the withdrawal notice is being delivered, or must otherwise comply with the depositary procedures in the case of a global note.

Notes to be repurchased must be delivered to the paying agent (in the case of physical notes) or the depositary procedures must be complied with (in the case of global notes) for the holder of those notes to be entitled to receive the fundamental change repurchase price.

S-45

Table of Contents

Compliance with Securities Laws

We will comply, in all material respects, with all federal and state securities laws in connection with a repurchase following a fundamental change (including complying with Rules 13e-4 and 14e-1 under the Exchange Act and filing any required Schedule TO, to the extent applicable) so as to permit effecting such repurchase in the manner described above. However, to the extent that our obligations to offer to repurchase and to repurchase notes pursuant to the provisions described above conflict with any law or regulation that is applicable to us and enacted after the date we initially issue the notes, our compliance with such law or regulation will not be considered to be a default of those obligations.

Repurchase by Third Party

Notwithstanding anything to the contrary, we will be deemed to satisfy our obligations to repurchase notes pursuant to the provisions described above if (i) one or more third parties conduct the repurchase offer and repurchase tendered notes in a manner that would have satisfied our obligations to do the same if conducted directly by us; and (ii) an owner of a beneficial interest in any note repurchased by such third party or parties will not receive a lesser amount (as a result of taxes, additional expenses or for any other reason) than such owner would have received had we repurchased such note.

No Repurchase Right in Certain Circumstances

Notwithstanding anything to the contrary, we will not be required to send a fundamental change notice, or offer to repurchase or repurchase any notes, as described above, in connection with a fundamental change occurring pursuant to clause (ii)(2) (or pursuant to clause (i) that also constitutes a fundamental change occurring pursuant to clause (ii)(2)) of the definition thereof, if:

We refer to any fundamental change with respect to which, in accordance with the provisions described above, we do not offer to repurchase any notes as an “exempted fundamental change.”

Consolidation, Merger and Asset Sale

For purposes of the notes, the description below under this section titled “—Consolidation, Merger and Asset Sale” supersedes, in its entirety, the information in the accompanying prospectus under the caption “Consolidation, Merger and Sale of Assets.”

S-46

Table of Contents

We will not consolidate with or merge with or into, or (directly, or indirectly through one or more of our subsidiaries) sell, lease or otherwise transfer, in one transaction or a series of transactions, all or substantially all of the assets of us and our subsidiaries, taken as a whole, to another person (a “business combination event”), unless:

At the effective time of a business combination event that complies with the provisions described above, the successor corporation (if not us) will succeed to, and may exercise every right and power of, us under the indenture and the notes, and, except in the case of a lease, the predecessor company will be discharged from its obligations under the indenture and the notes.

Notwithstanding anything to the contrary above, the provisions described above will not apply to any transfer of assets between or among us and any one or more of our “wholly owned subsidiaries” (as defined below under the caption “—Definitions”) not effected by merger or consolidation.

The definition of “business combination event” includes a reference to “all or substantially all” of our and our subsidiaries’ assets. There is no precise, established definition of the phrase “all or substantially all” under applicable law. Accordingly, there may be uncertainty as to whether the provisions described above would apply to a sale, lease or transfer of less than all of our and our subsidiaries’ assets.

Events of Default

For purposes of the notes, the description below under this section titled “—Events of Default” supersedes, in its entirety, the information in the accompanying prospectus under the caption “Events of Default.”

Generally

An “event of default” means the occurrence of any of the following:

S-47

Table of Contents

in each case where such default is not cured or waived within 30 days after notice to us by the trustee or to us and the trustee by holders of at least 25% of the aggregate principal amount of notes then outstanding;

Acceleration

If an event of default described in paragraph (9) above occurs with respect to us (and not solely with respect to a significant subsidiary of ours), then the principal amount of, and all accrued and unpaid interest on, all of the notes then outstanding will immediately become due and payable without any further action or notice by any person. If an event of default (other than an event of default described in paragraph (9) above with respect to us and not solely with respect to a significant subsidiary of ours) occurs and is continuing, then, except as described below under the caption “—Special Interest as Sole Remedy for Certain Reporting Defaults,” the trustee, by notice to us, or noteholders of at least 25% of the aggregate principal amount of notes then outstanding, by notice to us and the trustee, may declare the principal amount of, and all accrued and unpaid interest on, all of the notes then outstanding to become due and payable immediately.

Noteholders of a majority in aggregate principal amount of the notes then outstanding, by notice to us and the trustee, may, on behalf of all noteholders, rescind any acceleration of the notes and its consequences if (i) such rescission would not conflict with any judgment or decree of a court of competent jurisdiction; and (ii) all existing events of default (except the non-payment of principal of, or interest on, the notes that has become due solely because of such acceleration) have been cured or waived. No such rescission will affect any subsequent default or impair any right consequent thereto.

If any portion of the amount payable on the notes upon acceleration is considered by a court to be unearned interest (through the allocation of the value of the instrument to the embedded warrant or otherwise), then the court could disallow recovery of any such portion.

S-48

Table of Contents

Waiver of Past Defaults

An event of default pursuant to paragraph (1), (2), (4) or (6) above (that, in the case of paragraph (6) only, results from a default under any covenant that cannot be amended without the consent of each affected noteholder), and a default that could lead to such an event of default, can be waived only with the consent of each affected noteholder. Each other default or event of default may be waived, on behalf of all noteholders, by noteholders of a majority in aggregate principal amount of the notes then outstanding.

Notice of Defaults

If a default or event of default occurs, then we will, within 30 days after its first occurrence, notify the trustee, setting forth what action we are taking or propose to take with respect thereto. We must also provide the trustee annually, within 120 days after the end of each fiscal year, with a certificate as to whether any defaults or events of default have occurred or are continuing. If a default or event of default occurs and is continuing and is actually known to a responsible officer of the trustee, then the trustee must notify the noteholders of the same within 90 days after it occurs or, if it is not actually known to the trustee at such time, promptly (and in any event within 10 business days) after it becomes actually known to a responsible officer of the trustee. However, except in the case of a default or event of default in the payment of the principal of, or interest on, any note, the trustee may withhold such notice if and for so long as it in good faith determines that withholding such notice is in the interests of the noteholders.

Limitation on Suits; Absolute Rights of Noteholders

Except with respect to the rights referred to below, no noteholder may pursue any remedy with respect to the indenture or the notes, unless:

However, notwithstanding anything to the contrary, but without limiting the provisions described in the third paragraph under the caption “—Modification and Amendment,” the right of each holder of a note to receive payment or delivery, as applicable, of the principal of, or the redemption price or fundamental change repurchase price for, or any interest on, or the consideration due upon conversion of, such note on or after the respective due dates therefor, or to bring suit for the enforcement of any such payment or delivery on or after such respective due dates, will not be impaired or affected without the consent of such holder.

Noteholders of a majority in aggregate principal amount of the notes then outstanding may direct the time, method and place of conducting any proceeding for exercising any remedy available to the trustee or exercising any trust or power conferred on it. However, the trustee may refuse to follow any direction that conflicts with law, the indenture or the notes, or that, subject to the terms of the indenture, the trustee determines may be unduly prejudicial to the rights of other noteholders or may involve the trustee in liability, unless the trustee is offered security and indemnity satisfactory to the trustee against any loss, liability or expense to the trustee that may result from the trustee’s following such direction (it being understood that the trustee does not have an affirmative duty to determine whether any direction is prejudicial to any holder).

S-49

Table of Contents

Default Interest

Payments of any amounts due on the notes that are not made when due will accrue interest at a rate per annum equal to the stated interest on the notes.

Special Interest as Sole Remedy for Certain Reporting Defaults

Notwithstanding anything to the contrary described above, we may elect that the sole remedy for any event of default (a “reporting event of default”) pursuant to paragraph (6) above arising from our failure to comply with our obligations described below under the caption “—Exchange Act Reports” (including our obligations under Section 314(a)(1) of the Trust Indenture Act) will, for each of the first 365 calendar days on which a reporting event of default has occurred and is continuing, consist exclusively of the accrual of special interest on the notes. If we have made such an election, then (i) the notes will be subject to acceleration as described above on account of the relevant reporting event of default from, and including, the 366th calendar day on which a reporting event of default has occurred and is continuing or if we fail to pay any accrued and unpaid special interest when due; and (ii) special interest will cease to accrue on any notes from, and including, such 366th calendar day.

Any special interest that accrues on a note will be payable on the same dates and in the same manner as the stated interest on such note and will accrue at a rate per annum equal to 0.25% of the principal amount thereof for the first 180 days on which special interest accrues and, thereafter, at a rate per annum equal to 0.50% of the principal amount thereof. However, in no event will special interest accrue on any day on a note at a combined rate per annum that exceeds 0.50%. For the avoidance of doubt, any special interest that accrues on a note will be in addition to the stated interest that accrues on such note.

To make the election to pay special interest as described above, we must provide notice of such election to noteholders before the date on which each reporting event of default first occurs. The notice will also, among other things, briefly describe the periods during which and rate at which special interest will accrue and the circumstances under which the notes will be subject to acceleration on account of such reporting event of default.

Modification and Amendment

For purposes of the notes, the description below under this section titled “—Modification and Amendment” supersedes, in its entirety, the information in the accompanying prospectus under the caption “Modification and Waiver.”

We and the trustee may, with the consent of holders of a majority in aggregate principal amount of the notes then outstanding, amend or supplement the indenture or the notes or waive compliance with any provision of the indenture or the notes. However, without the consent of each affected noteholder, no amendment or supplement to the indenture or the notes, or waiver of any provision of the indenture or the notes, may:

S-50

Table of Contents

For the avoidance of doubt, pursuant to the first four bullet points above, no amendment or supplement to the indenture or the notes, or waiver of any provision of the indenture or the notes, may change the amount or type of consideration due on any note (whether on an interest payment date, redemption date, fundamental change repurchase date or the maturity date or upon conversion, or otherwise), or the date(s) or time(s) such consideration is payable or deliverable, as applicable, without the consent of each affected noteholder.

Notwithstanding anything to the contrary above, we and the trustee may amend or supplement the indenture or the notes without the consent of any noteholder to:

S-51

Table of Contents

Exchange Act Reports

We will send to the trustee copies of all reports that we are required to file with the SEC pursuant to Section 13(a) or 15(d) of the Exchange Act within 15 calendar days after the date that we are required to so file the same (after giving effect to all applicable grace periods under the Exchange Act). However, we need not send to the trustee any material for which we have received, or are seeking in good faith and have not been denied, confidential treatment by the SEC. Any report that we file with the SEC through the EDGAR system (or any successor thereto) will be deemed to be sent to the trustee at the time such report is so filed via the EDGAR system (or such successor). Upon the written request of any noteholder, the trustee will provide to the noteholder a copy of any report that we have sent the trustee pursuant to the provisions described above, other than a report that is deemed to be sent to the trustee pursuant to the preceding sentence. We will also comply with our other obligations under Section 314(a)(1) of the Trust Indenture Act.

Delivery of reports to the trustee is for informational purposes only, and the trustee’s receipt thereof shall not constitute actual or constructive notice of any information contained therein, including our compliance with any covenants under the indenture (as to which the trustee is entitled to certificates).

Discharge

For purposes of the notes, the description below under this section titled “—Discharge” supersedes, in its entirety, the information in the accompanying prospectus under the caption “Defeasance of Debt Securities and Certain Covenants in Certain Circumstances.”

Subject to the terms of the indenture, our obligations with respect to the notes under the indenture will be discharged if we deliver all outstanding notes to the trustee for cancellation, or if all outstanding notes have become due and payable (including upon conversion, if the consideration due upon such conversion has been determined) and we have irrevocably deposited with the trustee, or caused to be delivered to noteholders, sufficient cash or other consideration to satisfy all such amounts that have become due and payable.

Calculations

We will be responsible for making all calculations called for under the indenture or the notes, including determinations of the last reported sale price, the daily conversion value, the daily cash amount, the daily share amount, accrued interest on the notes and the conversion rate. We will make all calculations in good faith, and, absent manifest error, our calculations will be final and binding on all noteholders. We will provide a schedule of our calculations to the trustee and to any noteholder upon written request of such noteholder.

Trustee

The trustee under the indenture is Wilmington Trust, National Association. The trustee assumes no responsibility for the accuracy or completeness of the information contained in this prospectus supplement or the related documents. The trustee and its affiliates may from time to time in the future provide banking and other services to us in the ordinary course of business.

Notices

We will send all notices or communications to noteholders pursuant to the indenture in writing by first class mail, certified or registered, return receipt requested, or by overnight air courier guaranteeing next day delivery, to the noteholders’ respective addresses shown on the register for the notes. However, in the case of global notes, we are permitted to send notices or communications to noteholders pursuant to the depositary procedures, and notices and communications that we send in this manner will be deemed to have been properly sent to such noteholders in writing.

S-52

Table of Contents

No Personal Liability of Directors, Officers, Employees and Stockholders

For purposes of the notes, the description below under this section titled “—No Personal Liability of Directors, Officers, Employees and Stockholders” supersedes, in its entirety, the information in the accompanying prospectus under the caption “No Personal Liability of Directors, Officers, Employees or Securityholders.”

No past, present or future director, officer, employee, incorporator or stockholder of ours, as such, will have any liability for any obligations of ours under the indenture or the notes or for any claim based on, in respect of, or by reason of, such obligations or their creation. By accepting any note, each noteholder will be deemed to waive and release all such liability, and such waiver and release are part of the consideration for the issuance of the notes.

Governing Law; Waiver of Jury Trial

For purposes of the notes, the description below under this section titled “—Governing Law; Waiver of Jury Trial” supersedes, in its entirety, the information in the accompanying prospectus under the caption “Governing Law.”

The indenture and the notes, and any claim, controversy or dispute arising under or related to the indenture or the notes, will be governed by and construed in accordance with the laws of the state of New York. The indenture will provide that we, the trustee and each holder (by its acceptance of any note) will irrevocably waive, to the fullest extent permitted by applicable law, any and all right to trial by jury in any legal proceeding arising out of or relating to the indenture, the notes or the transactions contemplated by the indenture or the notes.

Submission to Jurisdiction

Any legal suit, action or proceeding arising out of or based upon the indenture or the transactions contemplated by the indenture may be instituted in the federal courts of the United States of America located in the City of New York or the courts of the State of New York, in each case located in the City of New York (collectively, the “specified courts”), and each party will be deemed to irrevocably submit to the non-exclusive jurisdiction of those courts in any such suit, action or proceeding. Service of any process, summons, notice or document by mail (to the extent allowed under any applicable statute or rule of court) to any party’s address as provided in the indenture will be effective service of process for any such suit, action or proceeding brought in any such court. Each of us, the trustee and each noteholder (by its acceptance of any note) will be deemed to irrevocably and unconditionally waive any objection to the laying of venue of any suit, action or other proceeding in the specified courts and to irrevocably and unconditionally waive and agree not to plead or claim any such suit, action or other proceeding has been brought in an inconvenient forum.

Definitions

“Affiliate” has the meaning set forth in Rule 144 under the Securities Act as in effect on the date we first issue the notes.

“Bid solicitation agent” means the person who is required to obtain bids for the trading price in accordance with the provisions described under the caption “—Conversion Rights—When the Notes May Be Converted—Conversion upon Satisfaction of Note Trading Price Condition” and in the definition of “trading price.”

“Board of directors” means our board of directors or a committee of such board duly authorized to act on behalf of such board.

“Business day” means any day other than a Saturday, a Sunday or any day on which the Federal Reserve Bank of New York is authorized or required by law or executive order to close or be closed.

“Capital stock” of any person means any and all shares of, interests in, rights to purchase, warrants or options for, participations in, or other equivalents of, in each case however designated, the equity of such person, but excluding any debt securities convertible into such equity.

“Close of business” means 5:00 p.m., New York City time.

S-53

Table of Contents

“Conversion price” means, as of any time, an amount equal to (i) $1,000 divided by (ii) the conversion rate in effect at such time.

“Conversion rate” initially means 61.6095 shares of our common stock per $1,000 principal amount of notes, which amount is subject to adjustment as described above under the caption “—Conversion Rights.” Whenever in this prospectus supplement we refer to the conversion rate as of a particular date without setting forth a particular time on such date, such reference will be deemed to be to the conversion rate immediately after the close of business on such date.

“Daily cash amount” means, with respect to any VWAP trading day, the lesser of (i) the applicable daily maximum cash amount; and (ii) the daily conversion value for such VWAP trading day.

“Daily conversion value” means, with respect to any VWAP trading day, one-50th of the product of (i) the conversion rate on such VWAP trading day; and (ii) the daily VWAP per share of our common stock on such VWAP trading day.

“Daily maximum cash amount” means, with respect to the conversion of any note, the quotient obtained by dividing (i) the specified dollar amount applicable to such conversion by (ii) 50.

“Daily share amount” means, with respect to any VWAP trading day, the quotient obtained by dividing (i) the excess, if any, of the daily conversion value for such VWAP trading day over the applicable daily maximum cash amount by (ii) the daily VWAP for such VWAP trading day. For the avoidance of doubt, the daily share amount will be zero for such VWAP trading day if such daily conversion value does not exceed such daily maximum cash amount.

“Daily VWAP” means, for any VWAP trading day, the per share volume-weighted average price of our common stock as displayed under the heading “Bloomberg VWAP” on Bloomberg page “GOSS <EQUITY> AQR” (or, if such page is not available, its equivalent successor page) in respect of the period from the scheduled open of trading until the scheduled close of trading of the primary trading session on such VWAP trading day (or, if such volume-weighted average price is unavailable, the market value of one share of our common stock on such VWAP trading day, determined, using a volume-weighted average price method, by a nationally recognized independent investment banking firm we select, which may include any of the underwriters). The daily VWAP will be determined without regard to after-hours trading or any other trading outside of the regular trading session.

“Depositary procedures” means, with respect to any transfer, exchange or transaction involving a global note or any beneficial interest therein, the rules and procedures of the depositary applicable to such transfer, exchange or transaction.

“DTC” means The Depository Trust Company.

“Ex-dividend date” means, with respect to an issuance, dividend or distribution on our common stock, the first date on which shares of our common stock trade on the applicable exchange or in the applicable market, regular way, without the right to receive such issuance, dividend or distribution (including pursuant to due bills or similar arrangements required by the relevant stock exchange). For the avoidance of doubt, any alternative trading convention on the applicable exchange or market in respect of our common stock under a separate ticker symbol or CUSIP number will not be considered “regular way” for this purpose.

“Exchange Act” means the U.S. Securities Exchange Act of 1934, as amended.

“Fundamental change” means any of the following events:

(i)a “person” or “group” (within the meaning of Section 13(d)(3) of the Exchange Act), other than us or our “wholly owned subsidiaries” (as defined below), or any employee benefit plans of ours or our wholly owned subsidiaries, files any report with the SEC indicating that such person or group has become the direct or indirect “beneficial owner” (as defined below) of shares of our common stock representing more than 50% of the voting power of all of our common stock;

(ii)the consummation of: (1) any sale, lease or other transfer, in one transaction or a series of transactions, of all or substantially all of the assets of us and our subsidiaries, taken as a whole, to any person, other

S-54

Table of Contents

than solely to one or more of our wholly owned subsidiaries; or (2) any transaction or series of related transactions in connection with which (whether by means of merger, consolidation, share exchange, combination, reclassification, recapitalization, acquisition, liquidation or otherwise) all of our common stock is exchanged for, converted into, acquired for, or constitutes solely the right to receive, other securities, cash or other property; provided, however, that any merger, consolidation, share exchange or combination of us pursuant to which the persons that directly or indirectly “beneficially owned” (as defined below) all classes of our common equity immediately before such transaction directly or indirectly “beneficially own,” immediately after such transaction, more than 50% of all classes of common equity of the surviving, continuing or acquiring company or other transferee, as applicable, or the parent thereof, in substantially the same proportions vis-à-vis each other as immediately before such transaction will be deemed not to be a fundamental change pursuant to this clause (ii);

(iii)our stockholders approve any plan or proposal for our liquidation or dissolution; or

(iv)our common stock ceases to be listed on any of The New York Stock Exchange, The NASDAQ Global Market or The NASDAQ Global Select Market (or any of their respective successors);

provided, however, that a transaction or event described in clause (i) or (ii) above will not constitute a fundamental change if at least 90% of the consideration received or to be received by the holders of our common stock (excluding cash payments for fractional shares or pursuant to dissenters rights), in connection with such transaction or event, consists of shares of common stock or other corporate common equity interests listed (or depositary receipts representing shares of common stock or other corporate common equity interests, which depositary receipts are listed) on any of The New York Stock Exchange, The NASDAQ Global Market or The NASDAQ Global Select Market (or any of their respective successors), or that will be so listed when issued or exchanged in connection with such transaction or event, and such transaction or event constitutes a common stock change event whose reference property consists of such consideration.

For the purposes of this definition, (x) any transaction or event described in both clause (i) and in clause (ii)(1) or (2) above (without regard to the proviso in clause (ii)) will be deemed to occur solely pursuant to clause (ii) above (subject to such proviso); and (y) whether a person is a “beneficial owner,” whether shares are “beneficially owned,” and percentage beneficial ownership, will be determined in accordance with Rule 13d-3 under the Exchange Act, but without regard to paragraph (d)(1) of such Rule.

“Holder” and “noteholder” mean a person in whose name a note is registered in the register for the notes.

“Last reported sale price” of our common stock for any trading day means the closing sale price per share (or, if no closing sale price is reported, the average of the last bid price and the last ask price per share or, if more than one in either case, the average of the average last bid prices and the average last ask prices per share) of our common stock on such trading day as reported in composite transactions for the principal U.S. national or regional securities exchange on which our common stock is then listed. If our common stock is not listed on a U.S. national or regional securities exchange on such trading day, then the last reported sale price will be the last quoted bid price per share of our common stock on such trading day in the over-the-counter market as reported by OTC Markets Group Inc. or a similar organization. If our common stock is not so quoted on such trading day, then the last reported sale price will be the average of the mid-point of the last bid price and the last ask price per share of our common stock on such trading day from a nationally recognized independent investment banking firm we select, which may include any of the underwriters.

“Make-whole fundamental change” means (i) a fundamental change (determined after giving effect to the proviso immediately after clause (iv) of the definition thereof, but without regard to the proviso to clause (ii)(2) of such definition); or (ii) the sending of any notice of redemption pursuant to the provisions described above under the caption “—Optional Redemption”; provided, however, that the sending of any such notice of redemption will constitute a make-whole fundamental change only with respect to the notes called (or deemed to be called pursuant to the provisions described above under the caption “—Optional Redemption”) for redemption pursuant to such notice and not with respect to any other notes.

S-55

Table of Contents

“Make-whole fundamental change conversion period” has the following meaning:

(i)in the case of a make-whole fundamental change pursuant to clause (i) of the definition thereof, the period from, and including, the make-whole fundamental change effective date of such make-whole fundamental change to, and including, the 35th trading day after such make-whole fundamental change effective date (or, if such make-whole fundamental change also constitutes a fundamental change (other than an exempted fundamental change), to, but excluding, the related fundamental change repurchase date); and

(ii)in the case of a make-whole fundamental change pursuant to clause (ii) of the definition thereof, the period from, and including, the date we send the redemption notice for the related redemption to, and including, the business day immediately before the related redemption date;

provided, however, that if the conversion date for the conversion of a note that has been called (or deemed called) for redemption occurs during the make-whole fundamental change conversion period for both a make-whole fundamental change occurring pursuant to clause (i) of the definition of “make-whole fundamental change” and a make-whole fundamental change resulting from such redemption pursuant to clause (ii) of such definition, then, solely for purposes of such conversion, (x) such conversion date will be deemed to occur solely during the make-whole fundamental change conversion period for the make-whole fundamental change with the earlier make-whole fundamental change effective date; and (y) the make-whole fundamental change with the later make-whole fundamental change effective date will be deemed not to have occurred.

“Make-whole fundamental change effective date” means (i) with respect to a make-whole fundamental change pursuant to clause (i) of the definition thereof, the date on which such make-whole fundamental change occurs or becomes effective; and (ii) with respect to a make-whole fundamental change pursuant to clause (ii) of the definition thereof, the applicable “redemption notice date” (as defined below).

“Market disruption event” means, with respect to any date, the occurrence or existence, during the one-half hour period ending at the scheduled close of trading on such date on the principal U.S. national or regional securities exchange or other market on which our common stock is listed for trading or trades, of any material suspension or limitation imposed on trading (by reason of movements in price exceeding limits permitted by the relevant exchange or otherwise) in our common stock or in any options contracts or futures contracts relating to our common stock.

“Maturity date” means June 1, 2027.

“Observation period” means, with respect to any note to be converted, (i) subject to clause (ii) below, if the conversion date for such note occurs before March 1, 2027, the 50 consecutive VWAP trading days beginning on, and including, the third VWAP trading day immediately after such conversion date; (ii) if such conversion date occurs on or after the date we have sent a redemption notice calling such note for redemption and before the related redemption date, the 50 consecutive VWAP trading days beginning on, and including, the 51st scheduled trading day immediately before such redemption date; and (iii) subject to clause (ii) above, if such conversion date occurs on or after March 1, 2027, the 50 consecutive VWAP trading days beginning on, and including, the 51st scheduled trading day immediately before the maturity date.

“Open of business” means 9:00 a.m., New York City time.

“Person” means any individual, corporation, partnership, limited liability company, joint venture, association, joint-stock company, trust, unincorporated organization or government or other agency or political subdivision thereof. Any division or series of a limited liability company, limited partnership or trust will constitute a separate “person.”

“Redemption notice date” means, with respect to a redemption, the date on which we send the related redemption notice pursuant to the provisions described above under the caption “—Optional Redemption.”

“Scheduled trading day” means any day that is scheduled to be a trading day on the principal U.S. national or regional securities exchange on which our common stock is then listed or, if our common stock is not then listed on a U.S. national or regional securities exchange, on the principal other market on which our common stock is then traded. If our common stock is not so listed or traded, then “scheduled trading day” means a business day.

S-56

Table of Contents

“Securities Act” means the U.S. Securities Act of 1933, as amended.

“Significant subsidiary” of any person means any subsidiary of that person that constitutes a “significant subsidiary” (as defined in Rule 1-02(w) of Regulation S-X under the Exchange Act) of that person; provided, however, that, if a subsidiary meets the criteria of clause (3) of the definition of “significant subsidiary” in Rule 1-02(w) but not clause (1) or (2) thereof, then such subsidiary will be deemed not to be a significant subsidiary of that person unless such subsidiary’s income from continuing operations before income taxes, exclusive of amounts attributable to any non-controlling interests, for the last completed fiscal year before the date of determination exceeds $25,000,000.

“Specified dollar amount” means, with respect to the conversion of a note to which combination settlement applies, the maximum cash amount per $1,000 principal amount of such note deliverable upon such conversion (excluding cash in lieu of any fractional share of common stock).

“Stock price” has the following meaning for any make-whole fundamental change: (i) if the holders of our common stock receive only cash in consideration for their shares of common stock in such make-whole fundamental change and such make-whole fundamental change is pursuant to clause (ii) of the definition of “fundamental change,” then the stock price is the amount of cash paid per share of our common stock in such make-whole fundamental change; and (ii) in all other cases, the stock price is the average of the last reported sale prices per share of common stock for the five consecutive trading days ending on, and including, the trading day immediately before the make-whole fundamental change effective date of such make-whole fundamental change.

“Subsidiary” means, with respect to any person, (i) any corporation, association or other business entity (other than a partnership or limited liability company) of which more than 50% of the total voting power of the capital stock entitled (without regard to the occurrence of any contingency, but after giving effect to any voting agreement or stockholders’ agreement that effectively transfers voting power) to vote in the election of directors, managers or trustees, as applicable, of such corporation, association or other business entity is owned or controlled, directly or indirectly, by such person or one or more of the other subsidiaries of such person; and (ii) any partnership or limited liability company where (x) more than 50% of the capital accounts, distribution rights, equity and voting interests, or of the general and limited partnership interests, as applicable, of such partnership or limited liability company are owned or controlled, directly or indirectly, by such person or one or more of the other subsidiaries of such person, whether in the form of membership, general, special or limited partnership or limited liability company interests or otherwise; and (y) such person or any one or more of the other subsidiaries of such person is a controlling general partner of, or otherwise controls, such partnership or limited liability company.

“Trading day” means any day on which (i) trading in our common stock generally occurs on the principal U.S. national or regional securities exchange on which our common stock is then listed or, if our common stock is not then listed on a U.S. national or regional securities exchange, on the principal other market on which our common stock is then traded; and (ii) there is no “market disruption event” (as defined above in this “—Definitions” section). If our common stock is not so listed or traded, then “trading day” means a business day.

“Trading price” of the notes on any trading day means the average of the secondary market bid quotations, expressed as a cash amount per $1,000 principal amount of notes, obtained by the bid solicitation agent for $1,000,000 (or such lesser amount as may then be outstanding) in principal amount of notes at approximately 3:30 p.m., New York City time, on such trading day from three nationally recognized independent securities dealers we select, which may include any of the underwriters; provided, however, that, if three such bids cannot reasonably be obtained by the bid solicitation agent but two such bids are obtained, then the average of the two bids will be used, and if only one such bid can reasonably be obtained by the bid solicitation agent, then that one bid will be used. If, on any trading day, (i) the bid solicitation agent cannot reasonably obtain at least one bid for $1,000,000 (or such lesser amount as may then be outstanding) in principal amount of notes from a nationally recognized independent securities dealer; (ii) we are not acting as the bid solicitation agent and we fail to instruct the bid solicitation agent to obtain bids when required; or (iii) the bid solicitation agent fails to solicit bids when required, then, in each case, the trading price per $1,000 principal amount of notes on such trading day will be deemed to be less than 98% of the product of the last reported sale price per share of our common stock on such trading day and the conversion rate on such trading day.

S-57

Table of Contents

“VWAP market disruption event” means, with respect to any date, (i) the failure by the principal U.S. national or regional securities exchange on which our common stock is then listed, or, if our common stock is not then listed on a U.S. national or regional securities exchange, the principal other market on which our common stock is then traded, to open for trading during its regular trading session on such date; or (ii) the occurrence or existence, for more than one half hour period in the aggregate, of any suspension or limitation imposed on trading (by reason of movements in price exceeding limits permitted by the relevant exchange or otherwise) in our common stock or in any options contracts or futures contracts relating to our common stock, and such suspension or limitation occurs or exists at any time before 1:00 p.m., New York City time, on such date.

“VWAP trading day” means a day on which (i) there is no VWAP market disruption event; and (ii) trading in our common stock generally occurs on the principal U.S. national or regional securities exchange on which our common stock is then listed or, if our common stock is not then listed on a U.S. national or regional securities exchange, on the principal other market on which our common stock is then traded. If our common stock is not so listed or traded, then “VWAP trading day” means a business day.

“Wholly owned subsidiary” of a person means any subsidiary of such person all of the outstanding capital stock or other ownership interests of which (other than directors’ qualifying shares) are owned by such person or one or more wholly owned subsidiaries of such person.

Book Entry, Settlement and Clearance

Global Notes

The notes will be initially issued in the form of one or more notes registered in the name of Cede & Co., as nominee of DTC, without interest coupons (the “global notes”), and will be deposited with the trustee as custodian for DTC.

Only persons who have accounts with DTC (“DTC participants”) or persons who hold interests through DTC participants may own beneficial interests in a global note. We expect that, under procedures established by DTC:

Book-Entry Procedures for Global Notes

All interests in a global note will be subject to the operations and procedures of DTC. Accordingly, you must allow for sufficient time in order to comply with those operations and procedures if you wish to exercise any of your rights with respect to the notes. The operations and procedures of DTC are controlled by DTC and may be changed at any time. None of us, the trustee or any of the underwriters (nor our or their agents) will be responsible for those operations or procedures.

DTC has advised us that it is:

S-58

Table of Contents

DTC was created to hold securities for its participants and to facilitate the clearance and settlement of securities transactions between its participants through electronic book-entry changes to the accounts of its participants. DTC’s participants include securities brokers and dealers (including the underwriters), banks and trust companies, clearing corporations and other organizations. Indirect access to DTC’s book-entry system is also available to other “indirect participants,” such as banks, brokers, dealers and trust companies, who directly or indirectly clear through or maintain a custodial relationship with a DTC participant. Purchasers of notes who are not DTC participants may beneficially own securities held by or on behalf of DTC only through DTC participants or indirect participants in DTC.

So long as DTC or its nominee is the registered owner of a global note, DTC or that nominee will be considered the sole owner or holder of the notes represented by that global note for all purposes under the indenture. Except as provided below, owners of beneficial interests in a global note:

As a result, each investor who owns a beneficial interest in a global note must rely on the procedures of DTC (and, if the investor is not a participant or an indirect participant in DTC, on the procedures of the DTC participant through whom the investor owns its interest) to exercise any rights of a noteholder under the indenture.

Payments on any global notes will be made to DTC’s nominee as the registered holder of the global note. Neither we nor the trustee (nor our agents or its agents) will have any responsibility or liability for the payment of amounts to owners of beneficial interests in a global note, for any aspect of the records relating to, or payments made on account of, those interests by DTC or for maintaining, supervising or reviewing any records of DTC relating to those interests. Payments by participants and indirect participants in DTC to the owners of beneficial interests in a global note will be governed by standing instructions and customary industry practice and will be the responsibility of those participants or indirect participants and DTC.

Transfers between participants in DTC will be effected under DTC’s procedures and will be settled in same-day funds.

Certificated Notes

A global note will be exchanged, pursuant to customary procedures, for one or more physical notes only if:

S-59

Table of Contents

Description of Other Indebtedness

You should read “Note 5. Long-Term Debt” of our Condensed Consolidated Financial Statements in our Quarterly Report on Form 10-Q for the quarter ended March 31, 2020, which is incorporated by reference into this prospectus supplement and the accompanying prospectus, for a description of our current long-term indebtedness.

S-60

Table of Contents

Material U.S. Federal Income Tax Considerations

The following is a summary of the material U.S. federal income tax consequences of the purchase, ownership, disposition and conversion of notes and the ownership and disposition of shares of our common stock into which the notes may be converted, but does not purport to be a complete analysis of all potential tax effects. The effects of other U.S. federal tax laws, such as estate and gift tax laws, and any applicable state, local or non-U.S. tax laws are not discussed. This summary is based upon provisions of the Internal Revenue Code of 1986, as amended (the “Code”), applicable Treasury Regulations promulgated thereunder, judicial decisions, and published rulings and administrative pronouncements of the Internal Revenue Service (the “IRS”), in each case in effect as of the date hereof. These authorities may change or be subject to differing interpretations. Any such change or differing interpretation may be applied retroactively in a manner that could adversely affect an investor in the notes or the shares of our common stock into which the notes may be converted. We have not sought and will not seek any rulings from the IRS regarding the matters discussed below. There can be no assurance that the IRS or a court will not take a contrary position to that discussed below regarding the tax consequences of the purchase, ownership, disposition and conversion of the notes and the shares of our common stock into which the notes may be converted.

Except where noted, this summary addresses only a note or share of our common stock held as a “capital asset” within the meaning of Section 1221 of the Code (generally, property held for investment) by a beneficial owner who purchased the note on original issuance at its “issue price” (i.e., the first price at which a substantial amount of the notes is sold for cash to persons other than bond houses, brokers, or similar persons or organizations acting in the capacity of underwriters, placement agents or wholesalers). Furthermore, this summary does not address all aspects of U.S. federal income taxes relevant to investors in a note or our common stock (including the alternative minimum tax or the potential application of the Medicare contribution tax), nor does it address all tax consequences that may be relevant to investors subject to special rules, including, without limitation:

S-61

Table of Contents

If an entity or arrangement treated as a partnership for U.S. federal income tax purposes holds notes or our common stock, the tax treatment of a partner in the partnership will depend on the status of the partner, the activities of the partnership and certain determinations made at the partner level. Accordingly, partnerships holding notes or our common stock and the partners in such partnerships should consult their tax advisors regarding the U.S. federal income tax consequences to them.

THIS DISCUSSION IS FOR INFORMATIONAL PURPOSES ONLY AND IS NOT TAX OR LEGAL ADVICE. INVESTORS SHOULD CONSULT THEIR TAX ADVISORS WITH RESPECT TO THE APPLICATION OF THE U.S. FEDERAL INCOME TAX LAWS TO THEIR PARTICULAR SITUATIONS AS WELL AS ANY TAX CONSEQUENCES OF THE PURCHASE, OWNERSHIP, DISPOSITION AND CONVERSION OF NOTES AND THE OWNERSHIP AND DISPOSITION OF SHARES OF OUR COMMON STOCK ARISING UNDER OTHER U.S. FEDERAL TAX LAWS (INCLUDING ESTATE AND GIFT TAX LAWS), UNDER THE LAWS OF ANY STATE, LOCAL OR NON-U.S. TAXING JURISDICTION OR UNDER ANY APPLICABLE INCOME TAX TREATY.

As used herein, a “U.S. holder” is a beneficial owner of a note or our common stock received upon conversion of a note that is, for U.S. federal income tax purposes:

A “non-U.S. holder” is a beneficial owner of a note or our common stock received upon conversion of a note that is an individual, corporation (or any other entity treated as a corporation for U.S. federal income tax purposes), estate or trust that is not a U.S. holder. Special rules may apply to certain non-U.S. holders. Consequently, non-U.S. holders should consult their tax advisors to determine the U.S. federal, state, local, non-U.S. and other tax consequences that may be relevant to them in light of their particular circumstances.

Consequences to U.S. Holders

Interest on the Notes

Stated interest on a note generally will be taxable to a U.S. holder as ordinary income at the time it is received or accrued in accordance with the U.S. holder’s usual method of accounting for tax purposes. It is anticipated, and this discussion assumes, that the notes will be issued with less than de minimis original issue discount for U.S. federal income tax purposes.

S-62

Table of Contents

Additional Payments

In certain circumstances, we may be obligated to make payments on the notes in excess of stated principal and interest. We believe and intend to take the position that these contingencies will not cause the notes to be treated as contingent payment debt instruments under the applicable Treasury Regulations. Assuming this position is respected by the IRS, a U.S. holder will be required to include in income the amounts of any such additional payments at the time such payments are received or accrued, in accordance with such U.S. holder’s method of accounting for U.S. federal income tax purposes. Our position is binding on a U.S. holder, unless it discloses in the proper manner to the IRS that it is taking a different position. If the IRS successfully challenged our position, and the notes were treated as contingent payment debt instruments, a U.S. holder would be required to accrue interest income at a rate higher than the yield to maturity of the notes (based on stated interest), regardless of the U.S. holder’s method of accounting, and to treat as ordinary income, rather than capital gain, any gain recognized on a sale, exchange, retirement or redemption of a note (including all gain realized upon conversion, even if the U.S. holder receives shares of our common stock). This discussion assumes that the notes will not be considered contingent payment debt instruments. U.S. holders are urged to consult their tax advisors regarding the potential application to the notes of the contingent payment debt instrument rules and the consequences thereof.

Sale, Exchange, Redemption or Other Taxable Disposition of Notes

Except as provided below under “—Conversion of Notes,” a U.S. holder generally will recognize gain or loss upon the sale, exchange, redemption or other taxable disposition of a note equal to the difference between the amount realized (excluding accrued but unpaid interest, which will be treated as described above under “—Interest on the Notes”) and such U.S. holder’s adjusted tax basis in the note. The amount realized by a U.S. holder will include the amount of any cash and the fair market value of any other property received for the note. A U.S. holder’s adjusted tax basis in a note generally will be equal to the amount that the U.S. holder paid for the note, increased to the extent any constructive distribution is treated as a dividend as provided below under “—Constructive Distributions.”

Any gain or loss recognized on a taxable disposition of a note generally will be capital gain or loss. If, at the time of the sale, exchange, redemption or other taxable disposition of a note, a U.S. holder held the note for more than one year, such gain or loss generally will be long-term capital gain or loss. Otherwise, such gain or loss will be short-term capital gain or loss. In the case of certain non-corporate U.S. holders (including individuals), long-term capital gains generally are eligible for a reduced rate of U.S. federal income tax. A U.S. holder’s ability to deduct capital losses may be limited.

Conversion of Notes

If a U.S. holder presents a note for conversion, it may receive solely cash, solely shares of our common stock, or a combination of cash and shares of our common stock in exchange for the note, depending upon our chosen settlement method.

If a U.S. holder receives solely cash in exchange for a note upon conversion, the U.S. holder’s gain or loss will be determined in the same manner as if the U.S. holder disposed of the notes in a taxable disposition (as described above under “—Sale, Exchange, Redemption or Other Taxable Disposition of Notes”).

If a U.S. holder receives solely shares of our common stock, and cash in lieu of a fractional share of our common stock, in exchange for notes upon conversion (excluding an exchange with a designated financial institution in lieu of conversion, as described in “—Exchange in Lieu of Conversion” below), the U.S. holder generally will not recognize gain or loss upon the conversion of the notes into shares of our common stock except to the extent of (1) cash received in lieu of a fractional share and (2) amounts received with respect to accrued but unpaid interest (which will be treated as described above under “—Interest on the Notes”).

S-63

Table of Contents

The amount of gain or loss a U.S. holder will recognize on the receipt of cash in lieu of a fractional share will be equal to the difference between the amount of cash the U.S. holder receives in respect of the fractional share and the portion of the U.S. holder’s adjusted tax basis in the note that is allocable to the fractional share. Any such gain or loss generally will be capital gain or loss and generally will be long-term capital gain or loss, if at the time of the conversion, the note has been held for more than one year.

The tax basis of shares of our common stock received upon a conversion (other than shares attributable to accrued but unpaid interest, the tax basis of which will equal their fair market value) will equal the adjusted tax basis of the note that was converted (excluding the portion of the adjusted tax basis that is allocable to any fractional share). The U.S. holder’s holding period for the shares of our common stock will include the period during which the U.S. holder held the notes, except that the holding period of any shares received with respect to accrued interest will commence on the day after the date of receipt.

As described below, the tax treatment of a conversion of a note into cash and shares of our common stock (excluding an exchange with a designated financial institution in lieu of conversion, the consequences of which are described below in “—Exchange in Lieu of Conversion”) is uncertain and subject to different possible characterizations, and U.S. holders should consult their tax advisors regarding the consequences of such a conversion.

Treatment as a Recapitalization. If a combination of cash and shares of our common stock is received by a U.S. holder upon conversion of a note, we intend to take the position that the notes are “securities” and to treat the conversion as a recapitalization for U.S. federal income tax purposes. In such case, gain, but not loss, will be recognized by the U.S. holder equal to the excess of the fair market value of our common stock and cash received (other than amounts attributable to accrued but unpaid interest, which will be treated as described above under “—Interest on the Notes”) over the U.S. holder’s adjusted tax basis in the note, but in no event will the gain recognized exceed the amount of cash received (excluding any cash received in lieu of a fractional share or attributable to accrued but unpaid interest). The amount of gain or loss recognized on the receipt of cash in lieu of a fractional share will be equal to the difference between the amount of cash received and the portion of the U.S. holder’s tax basis in our common stock received that is allocable to the fractional share, as described in the following paragraph. Any gain recognized by a U.S. holder on conversion of a note generally will be capital gain and generally will be long-term capital gain if, at the time of the conversion, the note has been held for more than one year.

The tax basis of our common stock received upon such a conversion (including any fractional share deemed to be received by the U.S. holder, but excluding any common stock attributable to accrued but unpaid interest, the tax basis of which will equal its fair market value) will equal the adjusted tax basis of the note that was converted, reduced by the amount of any cash received (excluding cash received in lieu of a fractional share or attributable to accrued but unpaid interest), and increased by the amount of gain, if any, recognized (other than gain recognized on any cash received with respect to a fractional share). A U.S. holder’s holding period for our common stock will include the period during which the U.S. holder held the note, except that the holding period of any common stock received with respect to accrued but unpaid interest will commence on the day after our common stock is received.

Alternative Treatment as Part Conversion and Part Redemption. If the conversion of a note into cash and common stock were not treated as a recapitalization as discussed above, the cash payment received would be treated as proceeds from the redemption of a portion of the note and taxed in the manner described above under “—Sale, Exchange, Redemption or Other Taxable Disposition of Notes,” in which case our common stock received on such a conversion would be treated as received upon a conversion of the other portion of the note, which generally would not be taxable to a U.S. holder except to the extent of any common stock received with respect to accrued but unpaid interest. In that case, the U.S. holder’s adjusted tax basis in the note would generally be allocated pro rata among our common stock and cash received based on the fair market value of our common stock and the cash received. The holding period for our common stock received in the conversion would include the holding period for the note, except that the holding period of any common stock received with respect to accrued but unpaid interest would commence on the day after our common stock is received.

S-64

Table of Contents

Constructive Distributions

The conversion rate of the notes will be adjusted in certain circumstances. Adjustments (or failures to make adjustments) that have the effect of increasing a U.S. holder’s proportionate interest in our assets or earnings and profits may, in some circumstances, result in a deemed distribution to the U.S. holder for U.S. federal income tax purposes even though no cash is received. Adjustments to the conversion rate made pursuant to a bona fide reasonable adjustment formula that has the effect of preventing the dilution of the interest of the holders of the notes, however, will generally not result in a deemed distribution to a U.S. holder.

Certain of the conversion rate adjustments provided in the notes (including, without limitation, adjustments in respect of taxable dividends to holders of our common stock) will not qualify as being pursuant to a bona fide reasonable adjustment formula. If such adjustments are made, a U.S. holder of notes will be deemed to have received a distribution, even though the U.S. holder has not received any cash as a result of such conversion rate adjustment. In addition, an adjustment to the conversion rate in connection with a make-whole fundamental change may be treated as a deemed distribution. Any deemed distribution will be taxable as a dividend, return of capital or capital gain as described below under “—Distributions.”

It is not entirely clear, however, whether a constructive dividend deemed paid to a non-corporate U.S. holder would be eligible for the lower applicable long-term capital gains rates as described below under “—Distributions.” It also is not entirely clear whether corporate U.S. holders would be entitled to claim the dividends received deduction with respect to any such constructive dividends. Generally, a U.S. holder’s adjusted tax basis in a note will be increased to the extent any such constructive distribution is treated as a dividend.

We are currently required to report the amount of any deemed distributions on our website or to the IRS and holders of notes not exempt from information reporting. The IRS proposed regulations addressing the amount and timing of deemed distributions, as well as obligations of withholding agents and filing and notice obligations of issuers in respect of such deemed distributions. If adopted as proposed, the regulations would generally provide that (1) the amount of a deemed distribution is the excess of the fair market value of the right to acquire stock immediately after the conversion rate adjustment over the fair market value of the right to acquire stock without the adjustment, (2) the deemed distribution occurs at the earlier of the date the adjustment occurs under the terms of the note and the date of the actual distribution of cash or property that results in the deemed distribution, (3) subject to certain limited exceptions, a withholding agent is required to impose any applicable withholding on deemed distributions and, if there is no associated cash payment, may set off its withholding obligations against payments on the notes (or, in some circumstances, any payments on our common stock) or sales proceeds received by or other funds or assets of an investor and (4) we are required to report the amount of any deemed distributions on our website or to the IRS and all holders of notes (including holders of notes that would otherwise be exempt from information reporting). The final regulations will be effective for deemed distributions occurring on or after the date of adoption, but beneficial owners of notes and withholding agents may rely on them prior to that date under certain circumstances.

Exchange in Lieu of Conversion

If a U.S. holder surrenders notes for conversion and such notes are exchanged with a designated financial institution, as described under “Description of Notes—Conversion Rights—Exchange in Lieu of Conversion,” the U.S. holder will be required to recognize gain or loss as described under “—Sale, Exchange, Redemption or Other Taxable Disposition of Notes.” In such case, the U.S. holder’s tax basis in our common stock received will equal the fair market value of the stock on the date of the exchange, and the U.S. holder’s holding period in our common stock received will begin on the day after the date of the exchange.

S-65

Table of Contents

Possible Effect of a Change in Conversion Consideration

In certain situations, the notes may become convertible or exchangeable into shares of an acquirer or other consideration. Depending on the circumstances, such an event could result in a deemed taxable exchange of the notes to a U.S. holder and the modified notes could be treated as newly issued at that time, potentially resulting in the recognition of taxable gain or loss. Furthermore, depending on the circumstances, subsequent to any such event, the U.S. federal income tax consequences of the conversion or exchange of the notes as well as the ownership of the notes and the shares of our common stock or other consideration received upon conversion or exchange may be different from the U.S. federal income tax consequences addressed in this discussion.

Distributions

Distributions, if any, made on our common stock, other than certain pro rata distributions of common shares, generally will be included in the income of a U.S. holder of our common stock as ordinary dividend income to the extent of our current or accumulated earnings and profits. Distributions in excess of our current and accumulated earnings and profits will be treated as a tax-free return of capital to the extent of a U.S. holder’s tax basis in our common stock and thereafter as capital gain from the sale or exchange of such common stock. Dividends received by a corporate U.S. holder may be eligible for a dividends received deduction, subject to applicable limitations. Dividends received by certain non-corporate U.S. holders (including individuals) generally are taxed at the lower rates applicable to long-term capital gains, provided certain holding period and other requirements are satisfied.

Sales, Certain Redemptions or Other Taxable Dispositions of Common Stock

Upon sales, certain redemptions or other taxable dispositions of our common stock, a U.S. holder generally will recognize gain or loss equal to the difference between the amount realized and the U.S. holder’s tax basis in our common stock. Any gain or loss recognized on a taxable disposition of common stock generally will be capital gain or loss. Such capital gain or loss generally will be long-term capital gain or loss if a U.S. holder’s holding period at the time of the sale, redemption or other taxable disposition of our common stock is more than one year. Long-term capital gains recognized by certain non-corporate U.S. holders (including individuals) generally are eligible for a reduced rate of U.S. federal income tax. The deductibility of capital losses is subject to limitations.

Consequences to Non-U.S. Holders

Interest on the Notes

Subject to the discussions below under “Information Reporting and Backup Withholding—Non-U.S. Holders” and “Additional Withholding Tax on Payments Made to Foreign Accounts,” U.S. federal income and withholding taxes will not apply to any payment of interest on a note to a non-U.S. holder that is not effectively connected with the non-U.S. holder’s conduct of a trade or business within the United States, provided that:

S-66

Table of Contents

If a non-U.S. holder cannot satisfy the requirements described above, payments of interest will be subject to a 30% U.S. federal withholding tax, unless the non-U.S. holder provides the applicable withholding agent with a properly executed (1) IRS Form W-8BEN or W-8BEN-E (or other applicable form) claiming an exemption from or reduction in withholding under an applicable income tax treaty or (2) IRS Form W-8ECI (or other applicable form) stating that interest paid on the notes is not subject to withholding tax because it is effectively connected with the non-U.S. holder’s conduct of a trade or business in the United States.

If a non-U.S. holder is engaged in a trade or business in the United States and interest on a note is effectively connected with the conduct of that trade or business (and, if required by an applicable income tax treaty, is attributable to a permanent establishment or fixed base maintained by the non-U.S. holder in the United States), then (although the non-U.S. holder will not be subject to the 30% withholding, provided the certification requirements discussed above are satisfied) the non-U.S. holder will be subject to federal income tax on that interest on a net-income basis generally in the same manner as if the non-U.S. holder were a U.S. holder. In addition, if the non-U.S. holder is a foreign corporation, it may be subject to a branch profits tax equal to 30% (or lesser rate under an applicable income tax treaty) of its earnings and profits for the taxable year, subject to adjustments, that are effectively connected with its conduct of a trade or business in the United States.

Distributions and Constructive Distributions

If we make distributions of cash or property on our common stock (and any constructive distributions resulting from certain adjustments, or failures to make adjustments, to the conversion rate of the notes, as described above under “Consequences to U.S. Holders—Constructive Distributions”), such distributions will constitute dividends for U.S. federal income tax purposes to the extent paid from our current or accumulated earnings and profits, as determined under U.S. federal income tax principles. Amounts not treated as dividends for U.S. federal income tax purposes will constitute a return of capital and first be applied against and reduce a non-U.S. holder’s adjusted tax basis in its common stock, but not below zero. Any excess will be treated as capital gain and will be treated as described below under “—Sale, Exchange, Certain Redemptions, Conversion or Other Taxable Dispositions of Notes or Common Stock.”

Subject to the discussion below on effectively connected income, dividends paid to a non-U.S. holder of our common stock will be subject to U.S. federal withholding tax at a rate of 30% of the gross amount of the dividends (or such lower rate specified by an applicable income tax treaty, provided the non-U.S. holder furnishes a valid IRS Form W-8BEN or W-8BEN-E (or other applicable documentation) certifying qualification for the lower treaty rate). If a non-U.S. holder holds the stock through a financial institution or other agent acting on the non-U.S. holder’s behalf, the non-U.S. holder will be required to provide appropriate documentation to the agent, who then will be required to provide certification to the applicable withholding agent, either directly or through other intermediaries. A non-U.S. holder that does not timely furnish the required documentation, but that qualifies for a reduced treaty rate, may obtain a refund of any excess amounts withheld by timely filing an appropriate claim for refund with the IRS. Non-U.S. Holders should consult their tax advisors regarding their entitlement to benefits under any applicable income tax treaty.

If dividends paid to a non-U.S. holder are effectively connected with the non-U.S. holder’s conduct of a trade or business within the United States (and, if required by an applicable income tax treaty, the non-U.S. holder maintains a permanent establishment or fixed base in the United States to which such dividends are attributable), the non-U.S. holder will be exempt from the U.S. federal withholding tax described above. To claim the exemption, the non-U.S. holder must furnish to the applicable withholding agent a valid IRS Form W-8ECI, certifying that the dividends are effectively connected with the non-U.S. holder’s conduct of a trade or business within the United States. Any such effectively connected dividends will be subject to U.S. federal income tax on a net income basis at the regular rates. A non-U.S. holder that is a corporation also may be subject to a branch profits tax at a rate of 30% (or such lower rate specified by an applicable income tax treaty) on such effectively connected dividends, as adjusted for certain items. Non-U.S. Holders should consult their tax advisors regarding any applicable tax treaties that may provide for different rules.

S-67

Table of Contents

Any applicable withholding taxes (including backup withholding) with respect to deemed dividends may be withheld from interest and payments upon conversion, repurchase or maturity of the notes or if any withholding taxes (including backup withholding) are paid on behalf of a non-U.S. holder, those withholding taxes may be set off against payments of cash or our common stock, if any, payable on the notes (or, in some circumstances, any payments on our common stock) or sales proceeds received by or other funds or assets of such non-U.S. holder.

Sale, Exchange, Certain Redemptions, Conversion or Other Taxable Dispositions of Notes or Common Stock

Subject to the discussion below under “Information Reporting and Backup Withholding— Non-U.S. Holders” and “Additional Withholding Tax on Payments Made to Foreign Accounts,” any gain recognized by a non-U.S. holder on the sale, exchange, certain redemptions, conversion or other taxable dispositions of a note or our common stock will not be subject to U.S. federal income tax unless:

Gain described in the first bullet point above generally will be subject to U.S. federal income tax on a net income basis at the regular rates. A non-U.S. holder that is a corporation also may be subject to a branch profits tax at a rate of 30% (or such lower rate specified by an applicable income tax treaty) on such effectively connected gain, as adjusted for certain items.

Gain described in the second bullet point above will be subject to U.S. federal income tax at a rate of 30% (or such lower rate specified by an applicable income tax treaty), which may be offset by U.S. source capital losses of the non-U.S. holder (even though the non-U.S. holder is not considered a resident of the United States), provided the non-U.S. holder has timely filed U.S. federal income tax returns with respect to such losses.

With respect to the third bullet point above, we believe we currently are not, and do not anticipate becoming, a USRPHC. Because the determination of whether we are a USRPHC depends, however, on the fair market value of our U.S. real property interests relative to the fair market value of our non-U.S. real property interests and our other business assets, there can be no assurance we currently are not a USRPHC or will not become one in the future.

Any amounts (including our common stock) that a non-U.S. holder receives on a sale, exchange, redemption, conversion or other taxable disposition of a note that are attributable to accrued but unpaid interest will be treated as interest and may be subject to U.S. federal income tax in accordance with the rules described above under “—Interest on the Notes.”

Information Reporting and Backup Withholding

U.S. Holders

Information reporting requirements generally will apply to payments of interest and deemed dividends on the notes (if any), dividends on our common stock and the proceeds of a sale of a note or common stock paid to a U.S. holder unless the U.S. holder is an exempt recipient, and if requested, certifies as to that status. Backup withholding generally will apply to those payments if the U.S. holder fails to provide an appropriate certification with its correct taxpayer identification number or certification of exempt status.

S-68

Table of Contents

Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules may be allowed as a refund or a credit against a U.S. holder’s U.S. federal income tax liability, provided the required information is timely furnished to the IRS.

Non-U.S. Holders

Payments of interest or deemed dividends on a note or payments of dividends on our common stock will not be subject to backup withholding, provided the applicable withholding agent does not have actual knowledge or reason to know the holder is a United States person and the holder either certifies its non-U.S. status, such as by furnishing a valid IRS Form W-8BEN, W-8BEN-E or W-8ECI, or otherwise establishes an exemption. However, information returns are required to be filed with the IRS in connection with interest and deemed dividends on the notes (if any) and any distributions on our common stock paid to the non-U.S. holder, regardless of whether any tax was actually withheld. In addition, proceeds of the sale or other taxable disposition of a note or our common stock within the United States or conducted through certain U.S.-related brokers generally will not be subject to backup withholding or information reporting, if the applicable withholding agent receives the certification described above and does not have actual knowledge or reason to know that such holder is a United States person, or the holder otherwise establishes an exemption. Proceeds of a disposition of a note or our common stock conducted through a non-U.S. office of a non-U.S. broker generally will not be subject to backup withholding or information reporting.

Copies of information returns that are filed with the IRS may also be made available under the provisions of an applicable treaty or agreement to the tax authorities of the country in which the non-U.S. holder resides or is established.

Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules may be allowed as a refund or a credit against a non-U.S. holder’s U.S. federal income tax liability, provided the required information is timely furnished to the IRS.

ADDITIONAL WITHHOLDING TAX ON PAYMENTS MADE TO FOREIGN ACCOUNTS

Withholding taxes may be imposed under Sections 1471 to 1474 of the Code (such Sections are commonly referred to as the Foreign Account Tax Compliance Act, or FATCA) on certain types of payments made to non-U.S. financial institutions and certain other non-U.S. entities. Specifically, a 30% withholding tax may be imposed on interest and dividends (including deemed dividends) on, or subject to the proposed Treasury Regulations discussed below, gross proceeds from the sale or other disposition of, a note or our common stock paid to a “foreign financial institution” or a “non-financial foreign entity” (each as defined in the Code), unless (1) the foreign financial institution undertakes certain diligence and reporting obligations, (2) the non-financial foreign entity either certifies it does not have any “substantial United States owners” (as defined in the Code) or furnishes identifying information regarding each substantial United States owner, or (3) the foreign financial institution or non-financial foreign entity otherwise qualifies for an exemption from these rules. If the payee is a foreign financial institution and is subject to the diligence and reporting requirements in clause (1) above, it must enter into an agreement with the U.S. Department of the Treasury requiring, among other things, that it undertake to identify accounts held by certain “specified United States persons” or “United States owned foreign entities” (each as defined in the Code), annually report certain information about such accounts, and withhold 30% on certain payments to non-compliant foreign financial institutions and certain other account holders. Foreign financial institutions located in jurisdictions that have an intergovernmental agreement with the United States governing FATCA may be subject to different rules.

Under the applicable Treasury Regulations and administrative guidance, withholding under FATCA generally applies to payments of interest and dividends (including deemed dividends) on a note or our common stock. While withholding under FATCA would also have applied to payments of gross proceeds from the sale or other disposition of notes or stock on or after January 1, 2019, proposed Treasury Regulations eliminate FATCA withholding on payments of gross proceeds entirely. Taxpayers generally may rely on these proposed Treasury Regulations until final Treasury Regulations are issued.

Prospective investors should consult their tax advisors regarding the potential application of withholding under FATCA to their investment in our notes and common stock.

S-69

Table of Contents

The Concurrent EQUITY Offering

Concurrently with this offering of notes, we are offering, through a separate prospectus supplement, 9,433,963 shares of our common stock, which we refer to as the “concurrent equity offering.” We have granted the underwriters of the concurrent equity offering an option to purchase up to an additional 1,415,094 shares of our common stock.

The completion of this offering is not contingent on the completion of the concurrent equity offering, and the completion of the concurrent equity offering is not contingent on the completion of this offering. Accordingly, you should not assume that the concurrent equity offering will be consummated on the terms described in this prospectus supplement, if at all, or that we will receive any additional proceeds from the concurrent equity offering. This prospectus supplement does not constitute an offer to sell, or the solicitation of an offer to buy, any securities being offered in the concurrent equity offering.

See “Use of Proceeds” for additional information regarding the use of proceeds from this offering and the concurrent equity offering.

S-70

Table of Contents

Underwriting

BofA Securities, Inc., SVB Leerink LLC and Piper Sandler & Co. are acting as the representatives of each of the underwriters named below. Subject to the terms and conditions set forth in an underwriting agreement among us and the underwriters, we have agreed to sell to the underwriters, and each of the underwriters has agreed, severally and not jointly, to purchase from us, the principal amount of notes set forth opposite its name below.`

Subject to the terms and conditions set forth in the underwriting agreement, the underwriters have agreed, severally and not jointly, to purchase all of the notes sold under the underwriting agreement if any of these notes are purchased. If an underwriter defaults, the underwriting agreement provides that the purchase commitments of the nondefaulting underwriters may be increased or the underwriting agreement may be terminated.

We have agreed to indemnify the underwriters against certain liabilities, including liabilities under the Securities Act, or to contribute to payments the underwriters may be required to make in respect of those liabilities.

The underwriters are offering the notes, subject to prior sale, when, as and if issued to and accepted by them, subject to approval of legal matters by their counsel, including the validity of the notes, and other conditions contained in the underwriting agreement, such as the receipt by the underwriters of officer’s certificates and legal opinions. The underwriters reserve the right to withdraw, cancel or modify offers to the public and to reject orders in whole or in part.

Commissions and Discounts

The representatives have advised us that the underwriters propose initially to offer the notes at a price of 100.00% of the principal amount of notes, plus accrued interest from the original issue date of the notes, if any. After the initial offering, the public offering price or any other term of the offering may be changed.

The following table shows the public offering price, underwriting discount and proceeds before expenses to us.  The information assumes either no exercise or full exercise by the underwriters of their option to purchase additional notes.

The expenses of the offering, not including the underwriting discount, are estimated to be approximately $700,000. We have also agreed to reimburse the underwriters for up to $10,000 for their Financial Industry Regulatory Authority, Inc. (“FINRA”) counsel fee. In accordance with FINRA Rule 5110, this reimbursement is deemed underwriting compensation for this offering.

S-71

Table of Contents

Over-allotment option

We have granted an option to the underwriters to purchase, for settlement within a period of 13 days from, and including, the date notes are first issued, up to an additional $30,000,000 aggregate principal amount of notes at the public offering price, less the underwriting discount, solely to cover over-allotments, if any. If the underwriters exercise this option, each will be obligated, subject to conditions contained in the underwriting agreement, to purchase an additional principal amount of the notes proportionate to that underwriter’s initial amount reflected in the above table.

New Issue of Notes

The notes are a new issue of securities with no established trading market.  We do not intend to apply for listing of the notes on any national securities exchange or for inclusion of the notes on any automated dealer quotation system.  We have been advised by the underwriters that they presently intend to make a market in the notes after completion of the offering.  However, they are under no obligation to do so and may discontinue any market-making activities at any time without any notice.  We cannot assure the liquidity of the trading market for the notes or that an active public market for the notes will develop.  If an active public trading market for the notes does not develop, the market price and liquidity of the notes may be adversely affected.  If the notes are traded, they may trade at a discount from their initial offering price, depending on prevailing interest rates, the market for similar securities, our operating performance and financial condition, general economic conditions and other factors.

Nasdaq Global Select Market Listing

Our common stock is listed on the Nasdaq Global Select Market under the symbol “GOSS.”

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A.

No Sales of Similar Securities

We, our executive officers and directors have agreed not to sell or transfer any common stock or securities convertible into, exchangeable for, exercisable for, or repayable with common stock, for 60 days after the date of this prospectus supplement without first obtaining the written consent of the representatives. Specifically, we and these other persons have agreed, with certain limited exceptions, not to directly or indirectly

S-72

Table of Contents

This lock-up provision applies to common stock and to securities convertible into or exchangeable or exercisable for or repayable with common stock. It also applies to common stock owned now or acquired later by the person executing the agreement or for which the person executing the agreement later acquires the power of disposition.  

Price Stabilization, Short Positions

In connection with the offering, the underwriters may purchase and sell the notes or shares of our common stock in the open market.  These transactions may include short sales, purchases on the open market to cover positions created by short sales and stabilizing transactions.  Short sales involve the sale by the underwriters of a greater principal amount of notes than they are required to purchase in the offering.  “Covered” short sales are sales made in an amount not greater than the underwriters’ option to purchase additional notes described above. The underwriters may close out any covered short position by either exercising their option to purchase additional notes or purchasing notes in the open market.  In determining the source of notes to close out the covered short position, the underwriters will consider, among other things, the price of notes available for purchase in the open market as compared to the price at which they may purchase notes through the option granted to them.  “Naked” short sales are sales in excess of such option.  The underwriters must close out any naked short position by purchasing notes in the open market.  A naked short position is more likely to be created if the underwriters are concerned that there may be downward pressure on the price of the notes in the open market after pricing that could adversely affect investors who purchase in the offering.  Stabilizing transactions consist of various bids for or purchases of notes or shares of our common stock made by the underwriters in the open market to peg, fix or maintain the price of the notes or our common stock prior to the completion of the offering.

Similar to other purchase transactions, the underwriters’ purchases to cover the syndicate short sales may have the effect of raising or maintaining the market price of the notes or preventing or retarding a decline in the market price of the notes.  As a result, the price of the notes may be higher than the price that might otherwise exist in the open market.

Neither we nor any of the underwriters make any representation or prediction as to the direction or magnitude of any effect that the transactions described above may have on the price of the notes or our common stock.  In addition, neither we nor any of the underwriters make any representation that the representatives will engage in these transactions or that these transactions, once commenced, will not be discontinued without notice.

Other Relationships

Some of the underwriters and their affiliates have engaged in, and may in the future engage in, investment banking and other commercial dealings in the ordinary course of business with us or our affiliates. They have received, or may in the future receive, customary fees and commissions for these transactions. BofA Securities, Inc. and SVB Leerink LLC served as underwriters in our initial public offering in February 2019. In addition, Silicon Valley Bank, an affiliate of SVB Leerink LLC, is a lender under our debt facility. BofA Securities, Inc. and SVB Leerink LLC are also acting as underwriters in the concurrent equity offering of our common stock, for which they will receive customary underwriting discounts and commissions.

In addition, in the ordinary course of their business activities, the underwriters and their affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers. Such investments and securities activities may involve securities and/or instruments of ours or our affiliates. The underwriters and their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

Electronic Distribution

In connection with the offering, certain of the underwriters or securities dealers may distribute this prospectus supplement and the accompanying prospectus by electronic means, such as e-mail.  

S-73

Table of Contents

European Economic Area and the United Kingdom

The notes are not intended to be offered, sold or otherwise made available to and should not be offered, sold or otherwise made available to any retail investor in the European Economic Area (“EEA”) or in the United Kingdom (“UK”). For these purposes, a retail investor means a person who is one (or more) of: (i) a retail client as defined in point (11) of Article 4(1) of Directive 2014/65/EU  (as amended, “MiFID II”); or (ii) a customer within the meaning of Directive (EU) 2016/97 (as amended, the “Insurance Distribution Directive”), where that customer would not qualify as a professional client as defined in point (10) of Article 4(1) of MiFID II; or (iii) not a qualified investor as defined in Regulation (EU) 2017/1129 (as amended, the “Prospectus Regulation”). Consequently no key information document required by Regulation (EU) No 1286/2014 (as amended, the “PRIIPs Regulation”) for offering or selling the notes or otherwise making them available to retail investors in the EEA or in the UK has been prepared and therefore offering or selling the notes or otherwise making them available to any retail investor in the EEA or in the UK may be unlawful under the PRIIPS Regulation.  This prospectus supplement has been prepared on the basis that any offer of the notes in any Member State of the EEA will be made pursuant to an exemption under the Prospectus Regulation from the requirement to publish a prospectus for offers of the notes. This prospectus supplement is not a prospectus for the purposes of the Prospectus Regulation.

References to Regulations or Directives include, in relation to the UK, those Regulations or Directives as they form part of UK domestic law by virtue of the European Union (Withdrawal) Act 2018 or have been implemented in UK domestic law, as appropriate.

The above selling restriction is in addition to any other selling restrictions set out below.

Notice to Prospective Investors in the United Kingdom

This document is for distribution only to persons who (i) have professional experience in matters relating to investments and who qualify as investment professionals within the meaning of Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005 (as amended, the “Financial Promotion Order”), (ii) are persons falling within Article 49(2)(a) to (d) (“high net worth companies, unincorporated associations etc.”) of the Financial Promotion Order, (iii) are outside the United Kingdom, or (iv) are persons to whom an invitation or inducement to engage in investment activity (within the meaning of Section 21 of the Financial Services and Markets Act 2000, as amended (“FSMA”)) in connection with the issue or sale of any securities may otherwise lawfully be communicated or caused to be communicated (all such persons together being referred to as “relevant persons”). This document is directed only at relevant persons and must not be acted on or relied on by persons who are not relevant persons. Any investment or investment activity to which this document relates is available only to relevant persons and will be engaged in only with relevant persons.

Notice to Prospective Investors in Switzerland

The notes may not be publicly offered in Switzerland and will not be listed on the SIX Swiss Exchange (“SIX”) or on any other stock exchange or regulated trading facility in Switzerland. This document has been prepared without regard to the disclosure standards for issuance prospectuses under art. 652a or art. 1156 of the Swiss Code of Obligations or the disclosure standards for listing prospectuses under art. 27 ff. of the SIX Listing Rules or the listing rules of any other stock exchange or regulated trading facility in Switzerland. Neither this document nor any other offering or marketing material relating to the notes or the offering may be publicly distributed or otherwise made publicly available in Switzerland.

Neither this document nor any other offering or marketing material relating to the offering, the Company, the notes have been or will be filed with or approved by any Swiss regulatory authority. In particular, this document will not be filed with, and the offer of the notes will not be supervised by, the Swiss Financial Market Supervisory Authority FINMA (FINMA), and the offer of the notes has not been and will not be authorized under the Swiss Federal Act on Collective Investment Schemes (“CISA”). The investor protection afforded to acquirers of interests in collective investment schemes under the CISA does not extend to acquirers of the notes.

S-74

Table of Contents

Notice to Prospective Investors in the Dubai International Financial Centre

This prospectus supplement relates to an Exempt Offer in accordance with the Offered Securities Rules of the Dubai Financial Services Authority (“DFSA”). This prospectus supplement is intended for distribution only to persons of a type specified in the Offered Securities Rules of the DFSA. It must not be delivered to, or relied on by, any other person. The DFSA has no responsibility for reviewing or verifying any documents in connection with Exempt Offers. The DFSA has not approved this prospectus supplement nor taken steps to verify the information set forth herein and has no responsibility for the prospectus supplement. The notes to which this prospectus supplement relates may be illiquid and/or subject to restrictions on their resale. Prospective purchasers of the notes offered should conduct their own due diligence on the notes. If you do not understand the contents of this prospectus supplement you should consult an authorized financial advisor.

Notice to Prospective Investors in Australia

No placement document, prospectus, product disclosure statement or other disclosure document has been lodged with the Australian Securities and Investments Commission (“ASIC”), in relation to the offering. This prospectus does not constitute a prospectus, product disclosure statement or other disclosure document under the Corporations Act 2001 (the “Corporations Act”), and does not purport to include the information required for a prospectus, product disclosure statement or other disclosure document under the Corporations Act.

Any offer in Australia of the notes may only be made to persons (the “Exempt Investors”) who are “sophisticated investors” (within the meaning of section 708(8) of the Corporations Act), “professional investors” (within the meaning of section 708(11) of the Corporations Act) or otherwise pursuant to one or more exemptions contained in section 708 of the Corporations Act so that it is lawful to offer the notes without disclosure to investors under Chapter 6D of the Corporations Act.

The notes applied for by Exempt Investors in Australia must not be offered for sale in Australia in the period of 12 months after the date of allotment under the offering, except in circumstances where disclosure to investors under Chapter 6D of the Corporations Act would not be required pursuant to an exemption under section 708 of the Corporations Act or otherwise or where the offer is pursuant to a disclosure document which complies with Chapter 6D of the Corporations Act.

Further, any shares of our common stock issued on conversion of the notes must not be offered for sale in Australia in the period of 12 months after the date of issue of those shares of common stock except in circumstances where disclosure to investors under Chapter 6D of the Corporations Act would not be required pursuant to an exemption under section 708 of the Corporations Act or otherwise or where the offer is pursuant to a disclosure document which complies with Chapter 6D of the Corporations Act. Any person acquiring notes or common stock must observe such Australian on-sale restrictions.

This prospectus supplement contains general information only and does not take account of the investment objectives, financial situation or particular needs of any particular person. It does not contain any securities recommendations or financial product advice. Before making an investment decision, investors need to consider whether the information in this prospectus supplement is appropriate to their needs, objectives and circumstances, and, if necessary, seek expert advice on those matters.

S-75

Table of Contents

Notice to Prospective Investors in Hong Kong

The notes have not been offered or sold and will not be offered or sold in Hong Kong, by means of any document, other than (a) to “professional investors” as defined in the Securities and Futures Ordinance (Cap. 571) of Hong Kong and any rules made under that Ordinance; or (b) in other circumstances which do not result in the document being a “prospectus” as defined in the Companies Ordinance (Cap. 32) of Hong Kong or which do not constitute an offer to the public within the meaning of that Ordinance. No advertisement, invitation or document relating to the notes has been or may be issued or has been or may be in the possession of any person for the purposes of issue, whether in Hong Kong or elsewhere, which is directed at, or the contents of which are likely to be accessed or read by, the public of Hong Kong (except if permitted to do so under the securities laws of Hong Kong) other than with respect to the notes which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” as defined in the Securities and Futures Ordinance and any rules made under that Ordinance.

Notice to Prospective Investors in Japan

The notes have not been and will not be registered under the Financial Instruments and Exchange Law of Japan (Law No. 25 of 1948, as amended) and, accordingly, will not be offered or sold, directly or indirectly, in Japan, or for the benefit of any Japanese Person or to others for re-offering or resale, directly or indirectly, in Japan or to any Japanese Person, except in compliance with all applicable laws, regulations and ministerial guidelines promulgated by relevant Japanese governmental or regulatory authorities in effect at the relevant time. For the purposes of this paragraph, “Japanese Person” shall mean any person resident in Japan, including any corporation or other entity organized under the laws of Japan.

Notice to Prospective Investors in Singapore

This prospectus supplement has not been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, the notes were not offered or sold or caused to be made the subject of an invitation for subscription or purchase and will not be offered or sold or caused to be made the subject of an invitation for subscription or purchase, and this prospectus supplement or any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the notes, has not been circulated or distributed, nor will it be circulated or distributed, whether directly or indirectly, to any person in Singapore other than (i) to an institutional investor (as defined in Section 4A of the Securities and Futures Act (Chapter 289) of Singapore, as modified or amended from time to time (the “SFA”)) pursuant to Section 274 of the SFA, (ii) to a relevant person (as defined in Section 275(2) of the SFA) pursuant to Section 275(1) of the SFA, or any person pursuant to Section 275(1A) of the SFA, and in accordance with the conditions specified in Section 275 of the SFA, or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA.

Where the notes are subscribed or purchased under Section 275 of the SFA by a relevant person which is:

S-76

Table of Contents

securities or securities-based derivatives contracts (each term as defined in Section 2(1) of the SFA) of that corporation or the beneficiaries’ rights and interest (howsoever described) in that trust shall not be transferred within six months after that corporation or that trust has acquired the notes pursuant to an offer made under Section 275 of the SFA except:

Notice to Prospective Investors in Canada

The notes may be sold only to purchasers purchasing, or deemed to be purchasing, as principal that are accredited investors, as defined in National Instrument 45-106 Prospectus Exemptions or subsection 73.3(1) of the Securities Act (Ontario), and are permitted clients, as defined in National Instrument 31-103 Registration Requirements, Exemptions and Ongoing Registrant Obligations.  Any resale of the notes must be made in accordance with an exemption from, or in a transaction not subject to, the prospectus requirements of applicable securities laws.

Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus supplement (including any amendment thereto) contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory.  The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory for particulars of these rights or consult with a legal advisor.

Pursuant to section 3A.3 (or, in the case of securities issued or guaranteed by the government of a non-Canadian jurisdiction, section 3A.4) of National Instrument 33-105 Underwriting Conflicts (NI 33-105), the underwriters are not required to comply with the disclosure requirements of NI 33-105 regarding underwriter conflicts of interest in connection with this offering.

S-77

Table of Contents

Legal Matters

The validity of the issuance of the securities offered hereby will be passed upon by our counsel, Latham & Watkins LLP, San Diego, California and certain attorneys and investment funds affiliated with the firm collectively own less than one percent of our common stock. The underwriters are being represented in connection with this offering by Cooley LLP, San Diego, California.

Experts

Ernst & Young LLP, independent registered public accounting firm, has audited our consolidated financial statements and related notes appearing in our 2019 Annual Report for the years ended December 31, 2018 and 2019, as set forth in their report therein, and incorporated herein by reference. Such financial statements have been incorporated herein by reference in reliance on Ernst & Young LLP’s report, given on their authority as experts in accounting and auditing.

Where You Can Find More Information

We have filed with the SEC a registration statement on Form S-3 under the Securities Act, of which this prospectus supplement forms a part. The rules and regulations of the SEC allow us to omit from this prospectus supplement and the accompanying prospectus certain information included in the registration statement. For further information about us and the securities we are offering under this prospectus supplement, you should refer to the registration statement and the exhibits and schedules filed with the registration statement. With respect to the statements contained in this prospectus supplement and the accompanying prospectus regarding the contents of any agreement or any other document, in each instance, the statement is qualified in all respects by the complete text of the agreement or document, a copy of which has been filed as an exhibit to the registration statement.

We file reports, proxy statements and other information with the SEC. The SEC maintains a website that contains reports, proxy and information statements and other information about issuers, such as us, who file electronically with the SEC. The address of that website is http://www.sec.gov.

Our website address is www.gossamerbio.com. The information on, or accessible through, our website is not part of, and is not incorporated into, this prospectus supplement or the accompanying prospectus and should not be considered part of this prospectus supplement or the accompanying prospectus.

Information Incorporated By Reference

The SEC’s rules allow us to “incorporate by reference” information into this prospectus supplement, which means that we can disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference is deemed to be part of this prospectus supplement and the accompanying prospectus, and subsequent information that we file with the SEC will automatically update and supersede that information. Any statement contained in a previously filed document incorporated by reference will be deemed to be modified or superseded for purposes of this prospectus supplement and the accompanying prospectus to the extent that a statement contained in this prospectus supplement or the accompanying prospectus modifies or replaces that statement.

We incorporate by reference our documents listed below and any future filings made by us with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act between the date of this prospectus supplement and the termination of the offering of the securities described in this prospectus supplement. We are not, however, incorporating by reference any documents or portions thereof, whether specifically listed below or filed in the future, that are not deemed “filed” with the SEC, including our Compensation Committee report and performance graph or any information furnished pursuant to Items 2.02 or 7.01 of Form 8-K or related exhibits furnished pursuant to Item 9.01 of Form 8-K.

S-78

Table of Contents

This prospectus supplement and the accompanying prospectus incorporate by reference the documents set forth below that have previously been filed with the SEC:

All reports and other documents we subsequently file pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act prior to the termination of this offering, excluding any information furnished to, rather than filed with, the SEC, will also be incorporated by reference into this prospectus supplement and the accompanying prospectus and deemed to be part of this prospectus supplement and the accompanying prospectus from the date of the filing of such reports and documents.

You may request a free copy of any of the documents incorporated by reference in this prospectus supplement and the accompanying prospectus (other than exhibits, unless they are specifically incorporated by reference in the documents) by writing or telephoning us at the following address:

Gossamer Bio, Inc.

Attention: Corporate Secretary

3013 Science Park Road

San Diego, CA 92121

(858) 684-1300

S-79

Table of Contents

PROSPECTUS

Common Stock

Preferred Stock

Debt Securities

Warrants

Units

We may offer and sell the securities identified above from time to time in one or more offerings. This prospectus provides you with a general description of the securities.

Each time we offer and sell securities, we will provide a supplement to this prospectus that contains specific information about the offering and the amounts, prices and terms of the securities. The supplement may also add, update or change information contained in this prospectus with respect to that offering. You should carefully read this prospectus and the applicable prospectus supplement, together with the documents we incorporate by reference, before you invest in any of our securities.

We may offer and sell the securities described in this prospectus and any prospectus supplement to or through one or more underwriters, dealers and agents, or directly to purchasers, or through a combination of these methods.  If any underwriters, dealers or agents are involved in the sale of any of the securities, their names and any applicable purchase price, fee, commission or discount arrangement between or among them will be set forth, or will be calculable from the information set forth, in the applicable prospectus supplement. See the sections of this prospectus entitled “About this Prospectus” and “Plan of Distribution” for more information. No securities may be sold without delivery of this prospectus and the applicable prospectus supplement describing the method and terms of the offering of such securities.

Investing in our securities involves risks. See the “Risk Factors” on page 4 of this prospectus and any similar section contained in the applicable prospectus supplement concerning factors you should consider before investing in our securities.

Our common stock is listed on the Nasdaq Global Select Market under the symbol “GOSS.” On April 9, 2020, the last reported sale price of our common stock on the Nasdaq Global Select Market was $11.49 per share.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is April 10, 2020.

Table of Contents

TABLE OF CONTENTS

Table of Contents

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the U.S. Securities and Exchange Commission, or the SEC, as a “well-known seasoned issuer” as defined in Rule 405 under the Securities Act of 1933, as amended, which we refer to as the “Securities Act” in this prospectus, using a “shelf” registration process. By using a shelf registration statement, we may sell securities from time to time and in one or more offerings as described in this prospectus. Each time that we offer and sell securities, we will provide a prospectus supplement to this prospectus that contains specific information about the securities being offered and sold and the specific terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement or free writing prospectus may also add, update or change information contained in this prospectus with respect to that offering. If there is any inconsistency between the information in this prospectus and the applicable prospectus supplement or free writing prospectus, you should rely on the prospectus supplement or free writing prospectus, as applicable. Before purchasing any securities, you should carefully read both this prospectus and the applicable prospectus supplement (and any applicable free writing prospectuses), together with the additional information described under the heading “Where You Can Find More Information; Incorporation by Reference.”

We have not authorized anyone to provide you with any information or to make any representations other than those contained in this prospectus, any applicable prospectus supplement or any free writing prospectuses prepared by or on behalf of us or to which we have referred you.  We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you.  We will not make an offer to sell these securities in any jurisdiction where the offer or sale is not permitted.  You should assume that the information appearing in this prospectus and the applicable prospectus supplement to this prospectus is accurate only as of the date on its respective cover, that the information appearing in any applicable free writing prospectus is accurate only as of the date of that free writing prospectus, and that any information incorporated by reference is accurate only as of the date of the document incorporated by reference, unless we indicate otherwise.  Our business, financial condition, results of operations and prospects may have changed since those dates.  This prospectus incorporates by reference, and any prospectus supplement or free writing prospectus may contain and incorporate by reference, market data and industry statistics and forecasts that are based on independent industry publications and other publicly available information.  Although we believe these sources are reliable, we do not guarantee the accuracy or completeness of this information and we have not independently verified this information.  Although we are not aware of any misstatements regarding the market and industry data presented in this prospectus and the documents incorporated herein by reference, these estimates involve risks and uncertainties and are subject to change based on various factors, including those discussed under the heading “Risk Factors” contained in this prospectus, the applicable prospectus supplement and any applicable free writing prospectus, and under similar headings in other documents that are incorporated by reference into this prospectus.  Accordingly, investors should not place undue reliance on this information.

When we refer to “Gossamer,” “we,” “our,” “us” and the “Company” in this prospectus, we mean Gossamer Bio, Inc. and its subsidiaries, unless otherwise specified. When we refer to “you,” we mean the holders of the applicable series of securities.

This prospectus also includes trademarks, tradenames and service marks that are the property of other organizations. Solely for convenience, trademarks and tradenames referred to in this prospectus appear without the ® and ™ symbols, but those references are not intended to indicate, in any way, that we will not assert, to the fullest extent under applicable law, our rights or that the applicable owner will not assert its rights, to these trademarks and tradenames.

1

Table of Contents

WHERE YOU CAN FIND MORE INFORMATION; INCORPORATION BY REFERENCE

Available Information

We file reports, proxy statements and other information with the SEC. The SEC maintains a website that contains reports, proxy and information statements and other information about issuers, such as us, who file electronically with the SEC. The address of that website is http://www.sec.gov.

Our website address is www.gossamerbio.com. The information on our website, however, is not, and should not be deemed to be, a part of this prospectus.

This prospectus and any prospectus supplement are part of a registration statement that we filed with the SEC and do not contain all of the information in the registration statement. The full registration statement may be obtained from the SEC or us, as provided below. Forms of the indenture and other documents establishing the terms of the offered securities are or may be filed as exhibits to the registration statement or documents incorporated by reference in the registration statement. Statements in this prospectus or any prospectus supplement about these documents are summaries and each statement is qualified in all respects by reference to the document to which it refers. You should refer to the actual documents for a more complete description of the relevant matters. You may inspect a copy of the registration statement through the SEC’s website, as provided above.

Incorporation by Reference

The SEC’s rules allow us to “incorporate by reference” information into this prospectus, which means that we can disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference is deemed to be part of this prospectus, and subsequent information that we file with the SEC will automatically update and supersede that information. Any statement contained in this prospectus or a previously filed document incorporated by reference will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus or a subsequently filed document incorporated by reference modifies or replaces that statement.

We incorporate by reference our documents listed below and any future filings made by us with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended, which we refer to as the “Exchange Act” in this prospectus, between the date of this prospectus and the termination of the offering of the securities described in this prospectus. We are not, however, incorporating by reference any documents or portions thereof, whether specifically listed below or filed in the future, that are not deemed “filed” with the SEC, including our Compensation Committee report and performance graph or any information furnished pursuant to Items 2.02 or 7.01 of Form 8-K or related exhibits furnished pursuant to Item 9.01 of Form 8-K.

This prospectus and any accompanying prospectus supplement incorporate by reference the documents set forth below that have previously been filed with the SEC:

All reports and other documents we subsequently file pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act prior to the termination of this offering, but excluding any information furnished to, rather than filed with, the SEC, will also be incorporated by reference into this prospectus and deemed to be part of this prospectus from the date of the filing of such reports and documents.

You may request a free copy of any of the documents incorporated by reference in this prospectus (other than exhibits, unless they are specifically incorporated by reference in the documents) by writing or telephoning us at the following address:

2

Table of Contents

Gossamer Bio, Inc.

Attention: Corporate Secretary

3013 Science Park Road

San Diego, CA 92121

(858) 684-1300

Exhibits to the filings will not be sent, however, unless those exhibits have specifically been incorporated by reference in this prospectus or any accompanying prospectus supplement.

3

Table of Contents

THE COMPANY

We are a clinical-stage biopharmaceutical company focused on discovering, acquiring, developing and commercializing therapeutics in the disease areas of immunology, inflammation and oncology. Our goal is to be an industry leader in each of these therapeutic areas and to enhance and extend the lives of patients suffering from such diseases. To accomplish this goal, we have assembled a deeply experienced and highly skilled group of industry veterans, scientists, clinicians and key opinion leaders from leading biotechnology and pharmaceutical companies, as well as leading academic centers from around the world. Our collective immunology and translational discovery and development expertise serves as the foundation of our company. We intend to maintain a scientifically rigorous and inclusive corporate culture where employees strive to bring improved therapeutic options to patients.

We are pursuing product candidates with strong scientific rationale to address indications where there is both a high unmet need and an opportunity to develop best-in-class or first-in-class therapeutics. We currently have four clinical-stage product candidates, in addition to multiple preclinical programs.  

We were incorporated under the laws of the state of Delaware on October 26, 2015 under the name FSG, Bio, Inc. and changed our name to Gossamer Bio, Inc. in 2017. Our principal executive offices are located at 3013 Science Park Road, San Diego, California 92121, and our telephone number is (858) 684-1300.

RISK FACTORS

Investment in any securities offered pursuant to this prospectus and the applicable prospectus supplement involves risks. You should carefully consider the risk factors incorporated by reference to our most recent Annual Report on Form 10-K and any subsequent Quarterly Reports on Form 10-Q or Current Reports on Form 8-K we file after the date of this prospectus, and all other information contained or incorporated by reference into this prospectus, as updated by our subsequent filings under the Exchange Act, and the risk factors and other information contained in the applicable prospectus supplement before acquiring any of such securities. The occurrence of any of these risks might cause you to lose all or part of your investment in the offered securities.

4

Table of Contents

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and the documents incorporated by reference herein contain forward-looking statements within the meaning of Section 21E of the Exchange Act. All statements other than statements of historical facts contained in this prospectus and the documents incorporated by reference herein, including statements regarding our future results of operations and financial position, business strategy, prospective products, product approvals, research and development costs, timing and likelihood of success, plans and objectives of management for future operations and future results of anticipated products, are forward-looking statements. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. This prospectus and the documents incorporated by reference herein also contain estimates and other statistical data made by independent parties and by us relating to market size and growth and other data about our industry. This data involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. In addition, projections, assumptions and estimates of our future performance and the future performance of the markets in which we operate are necessarily subject to a high degree of uncertainty and risk.

In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “could,” “intend,” “target,” “project,” “contemplates,” “believes,” “estimates,” “predicts,” “potential” or “continue” or the negative of these terms or other similar expressions. The forward-looking statements in this prospectus and the documents incorporated by reference herein are only predictions. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our business, financial condition and results of operations. These forward-looking statements speak only as of the date of this prospectus and are subject to a number of risks, uncertainties and assumptions, which we discuss in greater detail in the documents incorporated by reference herein, including under the heading “Risk Factors” and elsewhere in this prospectus. The events and circumstances reflected in our forward-looking statements may not be achieved or occur and actual results could differ materially from those projected in the forward-looking statements. Moreover, we operate in an evolving environment. New risk factors and uncertainties may emerge from time to time, and it is not possible for management to predict all risk factors and uncertainties. Given these risks and uncertainties, you should not place undue reliance on these forward-looking statements.  Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained in this prospectus or the documents incorporated by reference herein, whether as a result of any new information, future events, changed circumstances or otherwise. For all forward-looking statements, we claim the protection of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995.

5

Table of Contents

USE OF PROCEEDS

We intend to use the net proceeds from the sale of the securities as set forth in the applicable prospectus supplement.

DIVIDEND POLICY

We have never declared or paid any cash dividends on our capital stock. We intend to retain future earnings, if any, to finance the operation of our business and do not anticipate paying any cash dividends in the foreseeable future. Any future determination related to our dividend policy will be made at the discretion of our board of directors after considering our financial condition, results of operations, capital requirements, business prospects and other factors our board of directors deems relevant, and subject to the restrictions contained in any future financing instruments. In addition, the terms of our credit facility restrict our ability to pay dividends, subject to certain exceptions.

6

Table of Contents

DESCRIPTION OF CAPITAL STOCK

The following description of our capital stock is not complete and may not contain all the information you should consider before investing in our capital stock. This description is summarized from, and qualified in its entirety by reference to, our amended and restated certificate of incorporation, which has been publicly filed with the SEC. See “Where You Can Find More Information; Incorporation by Reference.”

Our authorized capital stock consists of:

Common Stock

As of March 18, 2020, there were 66,336,562 shares of our common stock outstanding and held of record by 44 stockholders. Under the terms of our amended and restated certificate of incorporation, holders of our common stock are entitled to one vote for each share held on all matters submitted to a vote of stockholders, including the election of directors, and do not have cumulative voting rights. Accordingly, the holders of a majority of the outstanding shares of common stock entitled to vote in any election of directors can elect all of the directors standing for election, if they so choose, other than any directors that holders of any preferred stock we may issue may be entitled to elect. Subject to the supermajority votes for some matters, other matters shall be decided by the affirmative vote of our stockholders having a majority in voting power of the votes cast by the stockholders present or represented and voting on such matter. Our amended and restated certificate of incorporation and amended and restated bylaws also provide that our directors may be removed only for cause and only by the affirmative vote of the holders of at least two-thirds in voting power of the outstanding shares of capital stock entitled to vote thereon. In addition, the affirmative vote of the holders of at least two-thirds in voting power of the outstanding shares of capital stock entitled to vote thereon is required to amend or repeal, or to adopt any provision inconsistent with, several of the provisions of our amended and restated certificate of incorporation.

Subject to preferences that may be applicable to any then outstanding preferred stock, holders of common stock are entitled to receive ratably those dividends, if any, as may be declared by the board of directors out of legally available funds. In the event of our liquidation, dissolution or winding up, the holders of common stock will be entitled to share ratably in the assets legally available for distribution to stockholders after the payment of or provision for all of our debts and other liabilities, subject to the prior rights of any preferred stock then outstanding. Holders of common stock have no preemptive or conversion rights or other subscription rights and there are no redemption or sinking funds provisions applicable to the common stock. All outstanding shares of common stock are, and the common stock to be outstanding upon the closing of this offering will be, duly authorized, validly issued, fully paid and nonassessable. The rights, preferences and privileges of holders of common stock are subject to and may be adversely affected by the rights of the holders of shares of any series of preferred stock that we may designate and issue in the future.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A.

Preferred Stock

We currently have no outstanding shares of preferred stock. Under the terms of our amended and restated certificate of incorporation, our board of directors has the authority, without further action by our stockholders, to issue up to 70,000,000 shares of preferred stock in one or more series, to establish from time to time the number of shares to be included in each such series, to fix the dividend, voting and other rights, preferences and privileges of the shares of each wholly unissued series and any qualifications, limitations or restrictions thereon, and to increase or decrease the number of shares of any such series, but not below the number of shares of such series then outstanding. Our board of directors may authorize the issuance of preferred stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of the common stock. The issuance of preferred stock, while providing flexibility in connection with possible acquisitions and other corporate purposes, could, among other things, have the effect of delaying, deferring or preventing a change in our control and may adversely affect the market price of the common stock and the voting and other rights of the holders of common stock. We have no current plans to issue any shares of preferred stock.

7

Table of Contents

Prior to the issuance of shares of each series, the board of directors is required by the General Corporation Law of the State of Delaware, or the DGCL, and our amended and restated certificate of incorporation to adopt resolutions and file a certificate of designation with the Secretary of State of the State of Delaware. The certificate of designation fixes for each class or series the designations, powers, preferences, rights, qualifications, limitations and restrictions, including dividend rights, conversion rights, redemption privileges and liquidation preferences.

All shares of preferred stock offered by this prospectus will, when issued, be fully paid and nonassessable and will not have any preemptive or similar rights. Our board of directors may authorize the issuance of preferred stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of the common stock. The issuance of preferred stock, while providing flexibility in connection with possible acquisitions and other corporate purposes, could, among other things, have the effect of delaying, deferring or preventing a change in our control and may adversely affect the market price of the common stock and the voting and other rights of the holders of common stock.

We will describe in a prospectus supplement relating to the class or series of preferred stock being offered the following terms:

8

Table of Contents

Unless we specify otherwise in the applicable prospectus supplement, the preferred stock will rank, relating to dividends and upon our liquidation, dissolution or winding up:

The term equity securities does not include convertible debt securities.

Registration Rights

As of April 9, 2020, holders of 15,525,695 shares of our common stock are entitled to the following rights with respect to the registration of such shares for public resale under the Securities Act, pursuant to the amended and restated investor rights agreement by and among us and certain of our stockholders. The registration of shares of common stock as a result of the following rights being exercised would enable holders to trade these shares without restriction under the Securities Act when the applicable registration statement is declared effective.

Demand Registration Rights

Form S-1.    If at any time investors holding at least 666,667 shares of our common stock, which we refer to as major investors, who also hold at least 30% of the registrable securities request in writing that we effect a registration with respect to at least 50% of the registrable securities then outstanding (or a lesser percent if the anticipated aggregate offering price, net of selling expenses, would exceed $10 million) in an offering, we may be required to register their shares. We are obligated to effect at most two registrations for the holders of registrable securities in response to these demand registration rights, subject to certain exceptions.

Form S-3.    If at any time we are entitled under the Securities Act to register our shares on Form S-3, major investors holding at least 20% of the registrable securities request in writing that we register their shares for public resale on Form S-3 and the price to the public of the offering is $5.0 million or more, we will be required to provide notice to all holders of registrable securities and to use all reasonable efforts to effect such registration; provided, however, that we will not be required to effect such a registration if, within the preceding 12 months, we have already effected two registrations on Form S-3 for the holders of registrable securities.

If the holders requesting registration intend to distribute their shares by means of an underwriting, the underwriter of such offering will have the right to limit the numbers of shares to be underwritten for reasons related to the marketing of the shares.

Piggyback Registration Rights

If at any time we propose to register any shares of our common stock under the Securities Act, subject to certain exceptions, the holders of registrable securities will be entitled to notice of the registration and to include their shares of registrable securities in the registration. If our proposed registration involves an underwriting, the managing underwriter of such offering will have the right to limit the number of shares to be underwritten for reasons related to the marketing of the shares.

Indemnification

Our investor rights agreement contains customary cross indemnification provisions, under which we are obligated to indemnify holders of registrable securities in the event of material misstatements or omissions in the registration statement attributable to us, and they are obligated to indemnify us for material misstatements or omissions attributable to them.

9

Table of Contents

Expenses

Ordinarily, other than underwriting discounts and commissions, we will be required to pay all expenses incurred by us related to any registration effected pursuant to the exercise of these registration rights. These expenses may include all registration and filing fees, printing expenses, fees and disbursements of our counsel, reasonable fees and disbursements of a counsel for the selling securityholders, blue sky fees and expenses and the expenses of any special audits incident to the registration.

Termination of Registration Rights

The registration rights terminate upon the earlier of (1) February 12, 2024, (2) upon the closing of an acquisition of our company or (3) with respect to a particular holder, such time as Rule 144 or another similar exemption under the Securities Act is available for the sale of all shares by such holder without limitation during a three-month period without registration.

Anti-Takeover Effects of Delaware Law and Our Certificate of Incorporation and Bylaws

Some provisions of Delaware law, our amended and restated certificate of incorporation and our amended and restated bylaws contain provisions that could make the following transactions more difficult: an acquisition of us by means of a tender offer; an acquisition of us by means of a proxy contest or otherwise; or the removal of our incumbent officers and directors. It is possible that these provisions could make it more difficult to accomplish or could deter transactions that stockholders may otherwise consider to be in their best interest or in our best interests, including transactions which provide for payment of a premium over the market price for our shares.

These provisions, summarized below, are intended to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to encourage persons seeking to acquire control of us to first negotiate with our board of directors. We believe that the benefits of the increased protection of our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweigh the disadvantages of discouraging these proposals because negotiation of these proposals could result in an improvement of their terms.

Undesignated Preferred Stock

The ability of our board of directors, without action by the stockholders, to issue up to 70,000,000 shares of undesignated preferred stock with voting or other rights or preferences as designated by our board of directors could impede the success of any attempt to change control of us. These and other provisions may have the effect of deferring hostile takeovers or delaying changes in control or management of our company.

Stockholder Meetings

Our amended and restated bylaws provide that a special meeting of stockholders may be called only by our chairman of the board, chief executive officer or president, or by a resolution adopted by a majority of our board of directors.

Requirements for Advance Notification of Stockholder Nominations and Proposals

Our amended and restated bylaws establish advance notice procedures with respect to stockholder proposals to be brought before a stockholder meeting and the nomination of candidates for election as directors, other than nominations made by or at the direction of the board of directors or a committee of the board of directors.

Elimination of Stockholder Action by Written Consent

Our amended and restated certificate of incorporation and amended and restated bylaws eliminate the right of stockholders to act by written consent without a meeting.

10

Table of Contents

Staggered Board

Our board of directors is divided into three classes. The directors in each class will serve for a three-year term, one class being elected each year by our stockholders. This system of electing and removing directors may tend to discourage a third party from making a tender offer or otherwise attempting to obtain control of us, because it generally makes it more difficult for stockholders to replace a majority of the directors.

Removal of Directors

Our amended and restated certificate of incorporation provides that no member of our board of directors may be removed from office by our stockholders except for cause and, in addition to any other vote required by law, upon the approval of not less than two thirds of the total voting power of all of our outstanding voting stock then entitled to vote in the election of directors.

Stockholders Not Entitled to Cumulative Voting

Our amended and restated certificate of incorporation does not permit stockholders to cumulate their votes in the election of directors. Accordingly, the holders of a majority of the outstanding shares of our common stock entitled to vote in any election of directors can elect all of the directors standing for election, if they choose, other than any directors that holders of our preferred stock may be entitled to elect.

Delaware Anti-Takeover Statute

We are subject to Section 203 of the Delaware General Corporation Law, which prohibits persons deemed to be “interested stockholders” from engaging in a “business combination” with a publicly held Delaware corporation for three years following the date these persons become interested stockholders unless the business combination is, or the transaction in which the person became an interested stockholder was, approved in a prescribed manner or another prescribed exception applies. Generally, an “interested stockholder” is a person who, together with affiliates and associates, owns, or within three years prior to the determination of interested stockholder status did own, 15% or more of a corporation’s voting stock. Generally, a “business combination” includes a merger, asset or stock sale, or other transaction resulting in a financial benefit to the interested stockholder. The existence of this provision may have an anti-takeover effect with respect to transactions not approved in advance by the board of directors.

Choice of Forum

Our amended and restated certificate of incorporation provides that, unless we consent in writing to the selection of an alternative form, the Court of Chancery of the State of Delaware will be the sole and exclusive forum for: (1) any derivative action or proceeding brought on our behalf; (2) any action asserting a claim of breach of a fiduciary duty or other wrongdoing by any of our directors, officers, employees or agents to us or our stockholders, creditors or other constituents; (3) any action asserting a claim against us arising pursuant to any provision of the General Corporation Law of the State of Delaware or our amended and restated certificate of incorporation or amended and restated bylaws; (4) any action to interpret, apply, enforce or determine the validity of our certificate of incorporation or bylaws; or (5) any action asserting a claim governed by the internal affairs doctrine. The provision would not apply to suits brought to enforce a duty or liability created by the Exchange Act. In any case, stockholders will not be deemed to have waived our compliance with the federal securities laws and the rules and regulations thereunder. The enforceability of similar choice of forum provisions in other companies’ certificates of incorporation has been challenged in legal proceedings, and it is possible that a court could find these types of provisions to be inapplicable or unenforceable. Our restated certificate of incorporation also provides that any person or entity purchasing or otherwise acquiring any interest in shares of our capital stock will be deemed to have notice of and to have consented to this choice of forum provision.

11

Table of Contents

Amendment of Charter Provisions

The amendment of any of the above provisions, except for the provision making it possible for our board of directors to issue preferred stock, would require approval by holders of at least two thirds of the total voting power of all of our outstanding voting stock.

The provisions of Delaware law, our amended and restated certificate of incorporation and our amended and restated bylaws could have the effect of discouraging others from attempting hostile takeovers and, as a consequence, they may also inhibit temporary fluctuations in the market price of our common stock that often result from actual or rumored hostile takeover attempts. These provisions may also have the effect of preventing changes in the composition of our board and management. It is possible that these provisions could make it more difficult to accomplish transactions that stockholders may otherwise deem to be in their best interests.

12

Table of Contents

DESCRIPTION OF DEBT SECURITIES

The following description, together with the additional information we include in any applicable prospectus supplement or free writing prospectus, summarizes certain general terms and provisions of the debt securities that we may offer under this prospectus. When we offer to sell a particular series of debt securities, we will describe the specific terms of the series in a supplement to this prospectus. We will also indicate in the supplement to what extent the general terms and provisions described in this prospectus apply to a particular series of debt securities. To the extent the information contained in the prospectus supplement differs from this summary description, you should rely on the information in the prospectus supplement.

We may issue debt securities either separately, or together with, or upon the conversion or exercise of or in exchange for, other securities described in this prospectus. Debt securities may be our senior, senior subordinated or subordinated obligations and, unless otherwise specified in a supplement to this prospectus, the debt securities will be our direct, unsecured obligations and may be issued in one or more series.

The debt securities will be issued under an indenture between us and a trustee named in the prospectus supplement. We have summarized select portions of the indenture below. The summary is not complete. The form of the indenture has been filed as an exhibit to the registration statement and you should read the indenture for provisions that may be important to you. In the summary below, we have included references to the section numbers of the indenture so that you can easily locate these provisions. Capitalized terms used in the summary and not defined herein have the meanings specified in the indenture.

General

The terms of each series of debt securities will be established by or pursuant to a resolution of our board of directors and set forth or determined in the manner provided in a resolution of our board of directors, in an officer’s certificate or by a supplemental indenture. (Section 2.2) The particular terms of each series of debt securities will be described in a prospectus supplement relating to such series (including any pricing supplement or term sheet).

We can issue an unlimited amount of debt securities under the indenture that may be in one or more series with the same or various maturities, at par, at a premium, or at a discount. (Section 2.1) We will set forth in a prospectus supplement (including any pricing supplement or term sheet) relating to any series of debt securities being offered, the aggregate principal amount and the following terms of the debt securities, if applicable:

13

Table of Contents

14

Table of Contents

We may issue debt securities that provide for an amount less than their stated principal amount to be due and payable upon declaration of acceleration of their maturity pursuant to the terms of the indenture. We will provide you with information on the federal income tax considerations and other special considerations applicable to any of these debt securities in the applicable prospectus supplement.

If we denominate the purchase price of any of the debt securities in a foreign currency or currencies or a foreign currency unit or units, or if the principal of, and premium, if any, and interest on, any series of debt securities is payable in a foreign currency or currencies or a foreign currency unit or units, we will provide you with information on the restrictions, elections, general tax considerations, specific terms and other information with respect to that issue of debt securities and such foreign currency or currencies or foreign currency unit or units in the applicable prospectus supplement.

Transfer and Exchange

Each debt security will be represented by either one or more global securities registered in the name of The Depository Trust Company (“DTC” or the “Depositary”) or a nominee of the Depositary (we will refer to any debt security represented by a global debt security as a “book-entry debt security”), or a certificate issued in definitive registered form (we will refer to any debt security represented by a certificated security as a “certificated debt security”) as set forth in the applicable prospectus supplement. Except as set forth under the heading “Global Debt Securities and Book-Entry System” below, book-entry debt securities will not be issuable in certificated form.

Certificated Debt Securities. You may transfer or exchange certificated debt securities at any office we maintain for this purpose in accordance with the terms of the indenture. (Section 2.4) No service charge will be made for any transfer or exchange of certificated debt securities, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with a transfer or exchange. (Section 2.7)

You may effect the transfer of certificated debt securities and the right to receive the principal of, premium and interest on certificated debt securities only by surrendering the certificate representing those certificated debt securities and either reissuance by us or the trustee of the certificate to the new holder or the issuance by us or the trustee of a new certificate to the new holder.

Global Debt Securities and Book-Entry System. Each global debt security representing book-entry debt securities will be deposited with, or on behalf of, the Depositary, and registered in the name of the Depositary or a nominee of the Depositary. Please see the section entitled “Global Securities” for more information.

Covenants

We will set forth in the applicable prospectus supplement any restrictive covenants applicable to any issue of debt securities. (Article IV)

No Protection in the Event of a Change of Control

Unless we state otherwise in the applicable prospectus supplement, the debt securities will not contain any provisions that may afford holders of the debt securities protection in the event we have a change in control or in the event of a highly leveraged transaction (whether or not such transaction results in a change in control) that could adversely affect holders of debt securities.

Consolidation, Merger and Sale of Assets

We may not consolidate with or merge with or into, or convey, transfer or lease all or substantially all of our properties and assets to, any person (a “successor person”) unless:

15

Table of Contents

Notwithstanding the above, any of our subsidiaries may consolidate with, merge into or transfer all or part of its properties to us. (Section 5.1)

Events of Default

“Event of Default” means with respect to any series of debt securities, any of the following:

No Event of Default with respect to a particular series of debt securities (except as to certain events of bankruptcy, insolvency or reorganization) necessarily constitutes an Event of Default with respect to any other series of debt securities. (Section 6.1) The occurrence of certain Events of Default or an acceleration under the indenture may constitute an event of default under certain indebtedness of ours or our subsidiaries outstanding from time to time.

We will provide the trustee written notice of any Default or Event of Default within 30 days of becoming aware of the occurrence of such Default or Event of Default, which notice will describe in reasonable detail the status of such Default or Event of Default and what action we are taking or propose to take in respect thereof. (Section 6.1)

If an Event of Default with respect to debt securities of any series at the time outstanding occurs and is continuing, then the trustee or the holders of not less than 25% in principal amount of the outstanding debt securities of that series may, by a notice in writing to us (and to the trustee if given by the holders), declare to be due and payable immediately the principal of (or, if the debt securities of that series are discount securities, that portion of the principal amount as may be specified in the terms of that series) and accrued and unpaid interest, if any, on all debt securities of that series. In the case of an Event of Default resulting from certain events of bankruptcy, insolvency or reorganization, the principal (or such specified amount) of and accrued and unpaid interest, if any, on all outstanding debt securities will become and be immediately due and payable without any declaration or other act on the part of the trustee or any holder of outstanding debt securities. At any time after a declaration of acceleration with respect to debt securities of any series has been made, but before a judgment or decree for payment of the money due has been obtained by the trustee, the holders of a majority in principal amount of the outstanding debt securities of that series may rescind and annul the acceleration if all Events of Default, other than the non-payment of accelerated principal and interest, if any, with respect to debt securities of that series, have been cured or waived as provided in the indenture. (Section 6.2) We refer you to the prospectus supplement relating to any series of debt securities that are discount securities for the particular provisions relating to acceleration of a portion of the principal amount of such discount securities upon the occurrence of an Event of Default.

16

Table of Contents

The indenture provides that the trustee may refuse to perform any duty or exercise any of its rights or powers under the indenture, unless the trustee receives indemnity satisfactory to it against any cost, liability or expense that might be incurred by it in performing such duty or exercising such right or power. (Section 7.1(e)) Subject to certain rights of the trustee, the holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee or exercising any trust or power conferred on the trustee with respect to the debt securities of that series. (Section 6.12)

No holder of any debt security of any series will have any right to institute any proceeding, judicial or otherwise, with respect to the indenture or for the appointment of a receiver or trustee, or for any remedy under the indenture, unless:

Notwithstanding any other provision in the indenture, the holder of any debt security will have an absolute and unconditional right to receive payment of the principal of, and premium and any interest on, that debt security on or after the due dates expressed in that debt security and to institute suit for the enforcement of payment. (Section 6.8)

The indenture requires us, within 120 days after the end of our fiscal year, to furnish to the trustee a statement as to compliance with the indenture. (Section 4.3) If a Default or Event of Default occurs and is continuing with respect to the securities of any series and if it is known to a responsible officer of the trustee, the trustee shall mail to each holder of the securities of that series notice of a Default or Event of Default within 90 days after it occurs or, if later, after a responsible officer of the trustee has knowledge of such Default or Event of Default. The indenture provides that the trustee may withhold notice to the holders of debt securities of any series of any Default or Event of Default (except in payment on any debt securities of that series) with respect to debt securities of that series if the trustee determines in good faith that withholding notice is in the interest of the holders of those debt securities. (Section 7.5)

Modification and Waiver

We and the trustee may modify, amend or supplement the indenture or the debt securities of any series without the consent of any holder of any debt security:

17

Table of Contents

We may also modify and amend the indenture with the consent of the holders of at least a majority in principal amount of the outstanding debt securities of each series affected by the modifications or amendments. We may not make any modification or amendment without the consent of the holders of each affected debt security then outstanding if that amendment will:

Except for certain specified provisions, the holders of at least a majority in principal amount of the outstanding debt securities of any series may on behalf of the holders of all debt securities of that series waive our compliance with provisions of the indenture. (Section 9.2) The holders of a majority in principal amount of the outstanding debt securities of any series may on behalf of the holders of all the debt securities of such series waive any past default under the indenture with respect to that series and its consequences, except a default in the payment of the principal of, premium or any interest on, any debt security of that series; provided, however, that the holders of a majority in principal amount of the outstanding debt securities of any series may rescind an acceleration and its consequences, including any related payment default that resulted from the acceleration. (Section 6.13)

Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

Legal Defeasance. The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, we may be discharged from any and all obligations in respect of the debt securities of any series (subject to certain exceptions). We will be so discharged upon the deposit with the trustee, in trust, of money and/or U.S. government obligations or, in the case of debt securities denominated in a single currency other than U.S. dollars, government obligations of the government that issued or caused to be issued such currency, that, through the payment of interest and principal in accordance with their terms, will provide money or U.S. government obligations in an amount sufficient in the opinion of a nationally recognized firm of independent public accountants or investment bank to pay and discharge each installment of principal of, premium and interest on, and any mandatory sinking fund payments in respect of, the debt securities of that series on the stated maturity of those payments in accordance with the terms of the indenture and those debt securities.

18

Table of Contents

This discharge may occur only if, among other things, we have delivered to the trustee an opinion of counsel stating that we have received from, or there has been published by, the U.S. Internal Revenue Service a ruling or, since the date of execution of the indenture, there has been a change in the applicable U.S. federal income tax law, in either case to the effect that, and based thereon such opinion shall confirm that, the holders of the debt securities of that series will not recognize income, gain or loss for U.S. federal income tax purposes as a result of the deposit, defeasance and discharge and will be subject to U.S. federal income tax on the same amounts and in the same manner and at the same times as would have been the case if the deposit, defeasance and discharge had not occurred. (Section 8.3)

Defeasance of Certain Covenants. The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, upon compliance with certain conditions:

The conditions include:

No Personal Liability of Directors, Officers, Employees or Securityholders

None of our past, present or future directors, officers, employees or securityholders, as such, will have any liability for any of our obligations under the debt securities or the indenture or for any claim based on, or in respect or by reason of, such obligations or their creation. By accepting a debt security, each holder waives and releases all such liability. This waiver and release is part of the consideration for the issue of the debt securities. However, this waiver and release may not be effective to waive liabilities under U.S. federal securities laws, and it is the view of the SEC that such a waiver is against public policy.

Governing Law

The indenture and the debt securities, including any claim or controversy arising out of or relating to the indenture or the debt securities, will be governed by the laws of the State of New York.

The indenture will provide that we, the trustee and the holders of the debt securities (by their acceptance of the debt securities) irrevocably waive, to the fullest extent permitted by applicable law, any and all right to trial by jury in any legal proceeding arising out of or relating to the indenture, the debt securities or the transactions contemplated thereby.

19

Table of Contents

The indenture will provide that any legal suit, action or proceeding arising out of or based upon the indenture or the transactions contemplated thereby may be instituted in the federal courts of the United States of America located in the City of New York or the courts of the State of New York in each case located in the City of New York, and we, the trustee and the holder of the debt securities (by their acceptance of the debt securities) irrevocably submit to the non-exclusive jurisdiction of such courts in any such suit, action or proceeding.  The indenture will further provide that service of any process, summons, notice or document by mail (to the extent allowed under any applicable statute or rule of court) to such party’s address set forth in the indenture will be effective service of process for any suit, action or other proceeding brought in any such court.  The indenture will further provide that we, the trustee and the holders of the debt securities (by their acceptance of the debt securities) irrevocably and unconditionally waive any objection to the laying of venue of any suit, action or other proceeding in the courts specified above and irrevocably and unconditionally waive and agree not to plead or claim any such suit, action or other proceeding has been brought in an inconvenient forum. (Section 10.10)

20

Table of Contents

DESCRIPTION OF WARRANTS

We may issue warrants for the purchase of shares of our common stock or preferred stock or of debt securities. We may issue warrants independently or together with other securities, and the warrants may be attached to or separate from any offered securities. Each series of warrants will be issued under a separate warrant agreement to be entered into between us and the investors or a warrant agent. The following summary of material provisions of the warrants and warrant agreements is subject to, and qualified in its entirety by reference to, all the provisions of the warrant agreement and warrant certificate applicable to a particular series of warrants. The terms of any warrants offered under a prospectus supplement may differ from the terms described below. We urge you to read the applicable prospectus supplement and any related free writing prospectus, as well as the complete warrant agreements and warrant certificates that contain the terms of the warrants.

The particular terms of any issue of warrants will be described in the prospectus supplement relating to the issue. Those terms may include:

Holders of equity warrants will not be entitled to:

Each warrant will entitle its holder to purchase the principal amount of debt securities or the number of shares of preferred stock or common stock at the exercise price set forth in, or calculable as set forth in, the applicable prospectus supplement. Unless we otherwise specify in the applicable prospectus supplement, holders of the warrants may exercise the warrants at any time up to the specified time on the expiration date that we set forth in the applicable prospectus supplement. After the close of business on the expiration date, unexercised warrants will become void.

21

Table of Contents

A holder of warrant certificates may exchange them for new warrant certificates of different denominations, present them for registration of transfer and exercise them at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement. Until any warrants to purchase debt securities are exercised, the holder of the warrants will not have any rights of holders of the debt securities that can be purchased upon exercise, including any rights to receive payments of principal, premium or interest on the underlying debt securities or to enforce covenants in the applicable indenture. Until any warrants to purchase common stock or preferred stock are exercised, the holders of the warrants will not have any rights of holders of the underlying common stock or preferred stock, including any rights to receive dividends or payments upon any liquidation, dissolution or winding up on the common stock or preferred stock, if any.

22