Filed Pursuant to Rule 424(b)(4)
Registration No. 333-249316

PROSPECTUS SUPPLEMENT

(To prospectus dated October 15, 2020)

 Summit Therapeutics Inc.
Subscription Rights to Purchase Up to 14,312,977 Shares of Common Stock at the Initial Price

Summit Therapeutics Inc. is distributing at no charge to the holders of our common stock, par value $0.01 per share, non-transferable subscription rights to purchase up to 14,312,977 shares of common stock at the Initial Price (as defined below) with an aggregate offering value of up to $75,000,000. The subscription price per share of common stock shall be equal to the lesser of (i) $5.24 (the “Initial Price”) and (ii) the volume weighted average price of our common stock for the ten day trading period through and including the Expiration Date (as defined below) (the “Alternate Price”), as provided herein. Each stockholder will receive one subscription right entitling the holder to purchase 0.172598 shares of common stock at the Initial Price, for each share of our common stock owned at 5:00 p.m., Eastern Time, on April 9, 2021 (the “Record Date”). To the extent that the Alternate Price is lower than the Initial Price, we will sell additional shares of common stock, provided that we will not issue any fractional shares of common stock. If you fully exercise your basic subscription right and other stockholders do not fully exercise their basic subscription rights, you may also exercise an over-subscription right to purchase additional shares of common stock that remain unsubscribed at the expiration of the rights offering, subject to the availability and pro rata allocation of shares among persons exercising this over-subscription right.

The purpose of this rights offering is to raise equity capital in a cost-effective manner that provides all of our existing stockholders the opportunity to participate. The net proceeds will be used to repay all amounts outstanding under the unsecured promissory note in the amount of $55 million issued to the Company’s CEO and Chairman, Robert W. Duggan, on April 20, 2021, further patient enrollment into the Ri-CoDIFy Phase 3 clinical trial program of ridinilazole, obtain regulatory approval of ridinilazole and prepare for its commercial launch, develop early-stage research projects using the Company’s Discuva Platform, pursue business development opportunities to expand our pipeline of drug candidates and support general corporate purposes.

The subscription rights will be distributed and exercisable beginning on the Record Date. The subscription rights will expire and will have no value if they are not exercised prior to the expiration date of this rights offering, which is currently expected to be 5:00 p.m. Eastern Time, on May 10, 2021 (the “Expiration Date”), unless we, in our sole discretion, extend the period for exercising the subscription rights. We will extend the duration of the rights offering as required by applicable law, and may choose to extend the rights offering if we decide that changes in the market price of our common stock warrant an extension or if we decide that the degree of participation in this rights offering by holders of our common stock is less than the level we desire. You should carefully consider whether or not to exercise your subscription rights before the Expiration Date. We reserve the right to cancel the rights offering at any time before the expiration of the rights offering, for any reason.

Robert W. Duggan, our chief executive officer, chairman of our board of directors and the beneficial owner of approximately 69% of our outstanding common stock prior to this rights offering, has indicated that he intends to exercise at least all of his basic subscription rights, but has not made any formal binding commitment to do so.

There is no minimum number of shares of common stock that we must sell in order to complete the rights offering. If you exercise your rights in full, you may also exercise an over-subscription right to purchase additional shares of common stock that remain unsubscribed at the expiration of the rights offering, subject to the availability and allocation of shares of common stock among persons exercising this over-subscription right and certain other limitations as further described elsewhere in this prospectus supplement. Stockholders who do not participate in the rights offering will continue to own the same number of shares, but will own a smaller percentage of the total shares outstanding after the rights offering to the extent that other stockholders participate in the rights offering. Rights that are not exercised by the Expiration Date will expire and have no value.

We are distributing the rights and offering the underlying securities directly to you. We have not employed any brokers, dealers or underwriters in connection with the solicitation or exercise of rights in the rights offering and no commissions, fees or discounts will be paid in connection with the rights offering. Broadridge Corporate Issuer Solutions, Inc. is acting as the subscription agent and information agent for the rights offering. While certain of our directors, officers and other employees may solicit responses from you, those directors, officers and other employees will not receive any commissions or compensation for their services other than their normal compensation.

The subscription rights may not be sold or transferred except as required by operation of law.

Our common stock is listed on the Nasdaq Global Market under the symbol “SMMT.” On April 20, 2021, the last reported sale price for our common stock on the Nasdaq Global Market was $5.15 per share.

Investing in our securities involves risks. You should carefully review and consider the information contained in this prospectus supplement, including the risk factors beginning on page S-24 of this prospectus supplement, as well as the risk factors and other information contained in any documents we incorporate by reference into this prospectus supplement before exercising your subscription rights. See “Where You Can Find Additional Information” beginning on page S-51. Neither the Securities and Exchange Commission nor any state securities regulators have approved or disapproved of these securities or determined if this prospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is April 21, 2021.

Table of Contents

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About This Prospectus SUPPLEMENT

This prospectus supplement provides the terms of the rights offering and supplements the accompanying prospectus, filed on October 5, 2020 as part of a registration statement on Form S-3 that was declared effective by the United States Securities and Exchange Commission (the “SEC”) on October 15, 2020. The accompanying prospectus contains more general information about us and the securities we may offer from time to time, some which does not apply to this rights offering. To the extent any inconsistency or conflict exists between the information included in this prospectus supplement and the information included in the accompanying prospectus, the information included or incorporated by reference in this prospectus supplement updates and supersedes the information in the accompanying prospectus. This prospectus supplement incorporates by reference important business and financial information about us that is not included in or delivered with this prospectus supplement.

You should only rely on the information contained or incorporated by reference in this prospectus supplement and the accompanying prospectus. No person has been authorized to give any information or make any representations other than those contained or incorporated by reference in this prospectus supplement and the accompanying prospectus in connection with the offering described herein and therein, and, if given or made, such information or representations must not be relied upon as having been authorized by us.

You should read the entire prospectus, prospectus supplement and the documents incorporated by reference therein and herein, before making an investment decision. Neither the delivery of this prospectus supplement or the accompanying prospectus nor any sale made hereunder shall under any circumstances imply that the information contained or incorporated by reference herein is correct as of any date subsequent to the date hereof, as applicable. You should assume that the information appearing in this prospectus supplement, or any document incorporated by reference is accurate only as of the date of the applicable documents, regardless of the time of delivery of this prospectus supplement or any sale of securities. Our business, financial condition, results of operations and prospects may have changed since that date.

We are not making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. No action is being taken in any jurisdiction outside the United States to permit a public offering of our securities or possession or distribution of this prospectus supplement in that jurisdiction. Persons who come into possession of this prospectus supplement in jurisdictions outside the United States are required to inform themselves about, and to observe any restrictions as to, this offering and the distribution of this prospectus supplement applicable to those jurisdictions.

Unless the context requires otherwise, references in this prospectus supplement to “Summit, “we”, “us”, “our,” “ours,” “our company,” “our group” or similar terms refer to Summit Therapeutics Inc., a Delaware corporation, and its consolidated subsidiaries, unless expressly indicated or the context otherwise requires.

We own or have rights to trademarks, service marks, and trade names that we use in connection with the operation of our business, including our corporate name, logos and website names. Other trademarks, service marks, and trade names appearing in this prospectus supplement are the property of their respective owners. Solely for convenience, some of the trademarks, service marks, and trade names referred to in this prospectus supplement are listed without the ® and ™ symbols.

Cautionary Note Regarding Forward-Looking Statements

This prospectus supplement, the accompanying prospectus and the information incorporated by reference herein include “forward-looking statements” within the meaning of Section 27A of the Securities Act, and Section 21E of the Exchange Act. All statements contained or incorporated by reference herein, including statements regarding our strategy, future operations, future financial position, future revenue, projected costs, prospects, plans, objectives of management and expected market growth, other than statements of historical facts, are forward-looking statements. The words “anticipate,” “believe,” “estimate,” “expect,” “intend,” “may,” “plan,” “predict,” “project,” “potential,” “will,” “would,” “could,” “should,” “continue,” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words.

We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make. You are cautioned that these forward-looking statements are only predictions and are subject to risks, uncertainties and assumptions that are referenced in the section of any accompanying prospectus supplement entitled “Risk Factors.” You should also carefully review the risk factors and cautionary statements described in the other documents we file from time to time with the SEC, specifically our most recent Annual Report on Form 10-K, our Quarterly Reports on Form 10-Q and our Current Reports on Form 8-K. We undertake no obligation to revise or update any forward-looking statements, except to the extent required by law.

Prospectus Summary

This summary description about us and our business highlights selected information contained elsewhere in this prospectus supplement or incorporated in this prospectus supplement by reference. This summary does not contain all of the information you should consider before investing in our common stock. You should carefully read this entire prospectus supplement and accompanying prospectus, including each of the documents incorporated herein or therein by reference, before making an investment decision.

Company Overview

We are a biopharmaceutical company focused on the discovery, development and commercialization of novel antibiotics or other treatments for serious infectious diseases or other high unmet medical needs. We are conducting a Phase 3 clinical program focused on the infectious disease C. difficile infection, or CDI. We are seeking to expand our product candidate portfolio through the development of new mechanism, precision antibiotics using our proprietary Discuva Platform. We may also expand our product candidate portfolio through business development opportunities in infectious diseases or other areas of high unmet medical need. Our lead CDI product candidate is ridinilazole (formerly SMT19969), an orally administered small molecule antibiotic.

To date, we have financed our operations primarily through issuances of our common stock (and before the Redomiciliation Transaction issuances of Summit Therapeutics plc’s ordinary shares and American Depositary Shares, or ADSs), payments to us under our license and commercialization agreement with Eurofarma Laboratórios SA, or Eurofarma, payments to us under our now-terminated license and collaboration agreement with Sarepta, and development funding and other assistance from government entities, philanthropic, non-government and not for profit organizations and patient advocacy groups for our product candidates. In particular, we have received funding from BARDA, CARB-X, Innovate UK, Wellcome Trust and a number of not for profit organizations.

We have devoted substantially all of our efforts to research and development, including clinical trials. We have not completed the development of any drugs. We expect to continue to incur significant expenses and increasing operating losses for at least the next several years. The net losses we incur may fluctuate significantly from quarter to quarter and year to year, due to the nature and timing of our research and development activities. We anticipate that our expenses will increase substantially in connection with conducting clinical trials for our lead product candidate, ridinilazole (formerly SMT19969), for the treatment of patients with CDI and seeking marketing approval for ridinilazole in the United States, as well as other geographies. In addition, if we obtain marketing approval of ridinilazole in the United States or other jurisdictions where we retain commercial rights, we expect to incur significant sales, marketing, distribution and outsourced manufacturing expenses, as well as ongoing research and development expenses.

Recent Developments

On April 20, 2021, we entered into a Note Purchase Agreement (the “Purchase Agreement”) with Robert W. Duggan, the Company’s Chief Executive Officer, Chairman of the Company’s board of directors and beneficial owner of approximately 69% of the Company’s issued and outstanding common stock. Pursuant to the Purchase Agreement, Mr. Duggan has loaned the Company $55 million in exchange for the issuance by the Company of an unsecured promissory note in the amount of $55 million (the “Note”). The Note accrues interest at a rate per annum equal to 150% of the applicable 10 Year US Treasury rate, as adjusted monthly (initially estimated to be approximately 2.4%). The Company may prepay any portion of the Note at its option without penalty. The Note will mature and become due upon the earlier of (i) the consummation of a registered public offering with net proceeds of no less than $55 million or (ii) 13 months from the date of issuance of the Note. It is anticipated that the Note will be repaid in connection with the consummation of the rights offering.

Prior to entering into the Purchase Agreement, the Company had determined, with Mr. Duggan’s agreement, to rescind both the note purchase agreement entered into with Mr. Duggan on March 24, 2021 and the promissory note issued thereunder, and had repaid the principal amount under such note in full, without interest or penalty. The rescission was effective on April 20, 2021.

Corporate Information

Summit Therapeutics Inc. was incorporated in July 2020 under the laws of the state of Delaware. On September 18, 2020, Summit Therapeutics Inc., became the successor issuer to Summit Therapeutics plc, a public limited company incorporated in England and Wales for certain purposes under both the Securities Act of 1933, as amended (the “Securities Act”), and the Securities Exchange Act of 1934, as amended (the “Exchange Act”) pursuant to a United Kingdom court-approved scheme of arrangement. Our principal executive offices are located at One Broadway, 14th Floor, Cambridge, Massachusetts 02142, and our telephone number is (617) 514-7149. We maintain a website at www.summittxinc.com where general information about us is available. Our website, and the information contained therein, or that can be accessed through, our website, is not a part of this prospectus supplement, and the inclusion of our website address is an inactive textual reference only.

For additional information concerning the rights offering, see “The Rights Offering,” beginning on page S-32.

The information set forth in this prospectus supplement is based on 82,926,705 shares of common stock outstanding as of the Record Date, and assumes that no options or warrants are exercised, RSUs vest, new options are issued under our equity incentive plans or we otherwise issue additional shares of common stock prior to consummation of the rights offering.

Questions and Answers About The Rights Offering

The following are examples of what we anticipate will be common questions about the rights offering. The answers are based on selected information included elsewhere in this prospectus supplement. The following questions and answers do not contain all of the information that may be important to you and may not address all of the questions that you may have about the rights offering. This prospectus supplement and the documents incorporated by reference contain more detailed descriptions of the terms and conditions of the rights offering and provide additional information about us and about our business, including potential risks related to the rights offering, our common stock, and our business.

Exercising the subscription rights and investing in our securities involve a high degree of risk. We urge you to carefully read the section titled “Risk Factors” beginning on page S-24 of this prospectus supplement and all other information included in, or incorporated by reference into, this prospectus supplement in its entirety before you decide whether to exercise your subscription rights.

Any Excess Subscription Amount resulting from the reduction of the subscription price from the Initial Price to the Alternate Price will be put towards the purchase of additional shares of common stock (either towards your basic subscription right, if available, or towards the over-subscription right if you have already exercised your basic subscription right in full). The excess amount for any fractional shares of common stock will be returned to you as soon as practicable, in the form in which made. You will not receive interest or a deduction on any payments refunded to you under the rights offering.

In order to properly exercise your over-subscription right, you must deliver the subscription payment for exercise of your over-subscription right before the expiration of the rights offering. Because we will not know the total number of unsubscribed shares of common stock before the expiration of the rights offering, if you wish to maximize the number of shares you purchase pursuant to your over-subscription right, you will need to deliver payment in an amount equal to the aggregate subscription price for the maximum number of shares of common stock available, assuming that no stockholder other than you has purchased any shares of common stock pursuant to such stockholder’s basic subscription right and over-subscription right. Any excess subscription payments received by the subscription agent caused by proration will be returned by the subscription agent to you by mail, without interest or penalty, as soon as practicable after the Expiration Date of the rights offering. The subscription agent will return any excess payments in the form in which it was made. Any Excess Subscription Amount resulting from the reduction of the subscription price from the Initial Price to the Alternate Price will be put towards the purchase of additional shares of common stock (either towards your basic subscription right, if available, or towards the over-subscription right if you have already exercised your basic subscription right in full). See “The Rights Offering — Subscription Rights — Over-Subscription Rights” beginning on page S-32.

If you send a payment that is insufficient to purchase the number of shares of common stock you requested, or if the number of shares of common stock you requested is not specified in the forms, the payment received will be applied to exercise your subscription rights to the fullest extent possible based on the amount of the payment received, subject to the availability of shares of common stock in the rights offering and the elimination of fractional shares. Any excess subscription payments received by the subscription agent will be returned promptly, without interest, following the expiration of the rights offering.

Please note that we will not accept payment by means of uncertified personal check, bank draft or cashier’s check.

Robert W. Duggan, the beneficial owner of approximately 69% of our outstanding common stock prior to this rights offering, has indicated that he intends to exercise at least all of his basic subscription rights to purchase shares of common stock, but has not made any formal binding commitment to do so. If other stockholders do not exercise their subscription rights and Mr. Duggan exercises all of his subscription rights and over-subscription rights, Mr. Duggan would be the only stockholder to subscribe for shares of common stock in connection with this rights offering, which would result in Mr. Duggan becoming the beneficial owner of approximately 74% of our common stock. See the section titled “Prospectus Summary” above for information on how this percentage is calculated.

The issuance of shares of our common stock in the rights offering will dilute, and thereby reduce, your proportionate ownership in our shares of common stock, unless you fully exercise your basic subscription rights. In addition, the issuance of our common stock at a subscription price that is less than the market price as of the record date for the rights offering will likely reduce the price per share of our common stock held by you prior to the rights offering.

If your shares are held in your name such that you are the record holder, then you should send your subscription documents, rights certificate and subscription payment, as provided herein, by first class mail or courier service to Broadridge Corporate Issuer Solutions, Inc., the subscription agent. The address for delivery to the subscription agent is as follows:

Your delivery to a different address or other than by the methods set forth above will not constitute valid delivery. You, or, if applicable, your nominee, are solely responsible for ensuring the subscription agent receives your subscription documents, rights certificate, and subscription payment. You should allow sufficient time for delivery of your subscription materials to the subscription agent and clearance of payment before the expiration of the rights offering period.

Broadridge Corporate Issuer Solutions, Inc.
Attn: BCIS Re-Organization Dept.
P.O. Box 1317
Brentwood, NY 11717-0718

Risk Factors

You should carefully consider the risk factors set forth below, the other information contained in this prospectus supplement and any other risks described in our filings with the SEC including, but not limited to under Item 1A. "Risk Factors" included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2020, as amended and supplemented by subsequently filed Quarterly Reports on Form 10-Q, if any, and Current Reports on Form 8-K, before making an investment decision. Any of the following risks could materially and adversely affect our business, financial condition, results of operations, liquidity and cash flows. In such a case, you may lose all or part of your investment. The risks described below are not the only risks facing us. Additional risks and uncertainties not currently known to us or those we currently view to be immaterial may also materially adversely affect our business, financial condition, results of operations, liquidity and cash flows. If any of the risks or uncertainties described in this prospectus supplement or our SEC filings or any such additional risks and uncertainties actually occur, our business, financial condition or results of operations could be materially and adversely affected, which could cause our actual operating results to differ materially from those indicated or suggested by forward-looking statements made in this prospectus supplement or our SEC filings or presented elsewhere by management from time to time. In that case, the trading price of our common stock could decline and you could lose all or part of your investment. Please also see “Cautionary Note Regarding Forward-Looking Statements” beginning on page S-2.

Risks Related to the Rights Offering

The subscription price determined for this rights offering is not an indication of our value.

In determining the subscription price for the rights offering, our board of directors, with the advice and input of management and advisors, considered a number of factors, including: the likely cost of capital from other sources and the general conditions of the securities markets, the price at which our stockholders might be willing to participate in the rights offering, historical and current trading prices for our common stock, our need for liquidity and capital and the desire to provide an opportunity to our stockholders to participate in the rights offering on a pro rata basis. The subscription price is not necessarily related to our book value, net worth or any other established criteria of value and may or may not be considered the fair value of the common stock to be offered in the rights offering. The market price of our common stock may decline during or after the rights offering, including below the applicable subscription price. After the date of this prospectus supplement, our common stock may trade at prices above or below the subscription price.

The market price of our common stock may decline.

We cannot assure you that the market price of our common stock will not either increase or decline before the subscription rights expire. Depending upon the trading price of our common stock at the time of our announcement of the rights offering, the announcement of the rights offering and its terms, including the subscription price, together with the number of shares of common stock we could issue if the rights offering is completed, may result in a decrease in the trading price of our common stock. This decline may continue after the completion of rights offering. Further, if a substantial number of rights are exercised and the holders of the shares received in the rights offering choose to sell some or all of the shares of common stock, the resulting sales could depress the market price of our common stock.

There is no guarantee that by the time the shares are delivered to you, the market price of our common stock will be above the subscription price for such shares. Further, because the exercise of your rights is not revocable and because the rights are not transferable, you will not be able to revoke your subscription if the market price decreases prior to the delivery of the shares or transfer of the shares until after they are delivered.

There is no guarantee that the subscription price, whether it is set at the Initial Price or the Alternate Price, will be lower than the market price of our common stock at the time that the shares that you receive in the rights offering are delivered. Further, because the exercise of your rights is not revocable and because the rights are not transferable, you will not be able to revoke your subscription if the market price decreases prior to the delivery of the shares or transfer of the shares until after they are delivered to you. Accordingly, the subscription price at which you are purchasing shares of common stock may be above the prevailing market price by the time that the shares of common stock are purchased and delivered.

If you exercise your subscription rights and the market price of the common stock falls below the subscription price, then you will have committed to subscribe in the rights offering at a price that is higher than the market price. Moreover, we cannot assure you that you will ever be able to sell shares of common stock that you received in the rights offering at a price equal to or greater than the subscription price or exercise price. Until shares are issued to you in book-entry, or uncertificated, form upon expiration of the rights offering, you may not be able to sell the shares of our common stock that you receive in the rights offering. We will issue shares of our common stock that you received in the rights offering in book-entry, or uncertificated, form as soon as practicable after expiration of the rights offering. We will not pay you interest on funds delivered to the subscription agent pursuant to the exercise of rights.

If you do not exercise your subscription rights in full, your percentage ownership and voting rights in Summit will experience dilution.

If you choose not to exercise your subscription rights, you will retain your current number of shares of our common stock. If other stockholders fully exercise their subscription rights or exercise a greater proportion of their subscription rights than you exercise, the percentage of our common stock owned by these other stockholders will increase relative to your ownership percentage, and your voting and other rights in the Company will likewise be diluted.

The subscription rights are non-transferable and thus there will be no market for them.

You may not sell, transfer or assign your subscription rights to anyone else, unless as required by operation of law. We do not intend to list the subscription rights on any securities exchange or any other trading market. Because the subscription rights are non-transferable, there is no market or other means for you to directly realize any value associated with the subscription rights.

You may not be able to resell any shares of our common stock that you receive pursuant to the exercise of subscription rights immediately upon expiration of the subscription rights offering period or be able to sell your shares at a price equal to or greater than the subscription price.

If you exercise subscription rights, you may not be able to resell the common stock that you receive in the rights offering until you, or your custodian bank, broker, dealer or other nominee, if applicable, have received those shares. Moreover, you will have no rights as a stockholder of the shares you received in the rights offering until we issue the shares to you. Although we will endeavor to issue the shares as soon as practicable after completion of the rights offering, and after all necessary calculations have been completed, there may be a delay between the Expiration Date of the rights offering and the time that the shares are issued. In addition, we cannot assure you that, following the exercise of your subscription rights, you will be able to sell your common stock at a price equal to or greater than the subscription price.

Because no minimum subscription is required and because we do not have formal commitments from our stockholders for the entire amount we seek to raise pursuant to the rights offering, we cannot assure you of the amount of proceeds that we will receive from the rights offering.

No minimum subscription is required for consummation of the rights offering. Although Robert W. Duggan, the beneficial owner of approximately 69% of our outstanding common stock prior to this rights offering, has indicated that he intends to exercise at least all of his basic subscription rights, he has not made any formal binding commitment to do so, and we do not have formal commitments from our stockholders for the amount we seek to raise pursuant to the rights offering. It is also possible that no over-subscription rights will be exercised in connection with the rights offering. As a result, we cannot assure you of the amount of proceeds that we will receive in the rights offering. Therefore, if you exercise all or any portion of your subscription rights, but other stockholders do not, we may not raise the desired amount of capital in the rights offering, the market price of our common stock could be adversely impacted and we may find it necessary to pursue alternative means of financing, which may be dilutive to your investment.

Because we may terminate the rights offering at any time prior to the Expiration Date, your participation in the rights offering is not assured.

We do not intend, but have the right, to terminate the rights offering at any time prior to the Expiration Date. If we determine to terminate the rights offering, we will not have any obligation with respect to the subscription rights except to return any money received from subscribing stockholders as soon as practicable, without interest or deduction.

You will need to act promptly and carefully follow the subscription instructions, or your exercise of rights may be rejected.

Stockholders who desire to subscribe for shares of common stock in the rights offering must act promptly to ensure that all required forms and payments are actually received by the subscription agent prior to the Expiration Date, which is currently set to be 5:00 p.m. on May 10, 2021. If you are a beneficial owner of shares, you must act promptly to ensure that your custodian bank, broker, dealer or other nominee acts for you and that all required forms and payments are actually received by the subscription agent prior to the Expiration Date. Your nominee may establish a deadline prior to the Expiration Date by which you must provide it with your instructions to exercise your subscription rights and payment for your shares of common stock. We will not be responsible if your custodian bank, broker, dealer or nominee fails to ensure that all required forms and payments are actually received by the subscription agent prior to the Expiration Date. If you fail to complete and sign the required subscription forms, send an incorrect payment amount, or otherwise fail to follow the subscription procedures that apply to your desired transaction the subscription agent may, depending on the circumstances, reject your subscription or accept it to the extent of the payment received. Neither we nor our subscription agent will undertake to contact you concerning, or attempt to correct, an incomplete or incorrect subscription form or payment. We have the sole discretion to determine whether a subscription exercise properly follows the subscription procedures.

By participating in the rights offering and executing a rights certificate, you are making binding and enforceable representations to the Company.

By signing the rights certificate and exercising their rights, each stockholder agrees, solely with respect to such stockholder’s exercise of rights in the rights offering, that we have the right to void and cancel (and treat as if never exercised) any exercise of rights, and securities issued pursuant to an exercise of rights, if any of the agreements, representations or warranties of a subscriber in the subscription documents are false.

If you exercise the over-subscription right, you may not receive all of the shares of common stock for which you subscribe.

Exercise of the over-subscription right will only be honored if and to the extent that the basic subscription rights have not been exercised in full. If a sufficient number of shares of common stock are available, we will seek to honor your over-subscription request in full. If, however, over-subscription requests exceed the number of shares available to be purchased pursuant to the over-subscription right, we will allocate the available share proportionately among stockholders who exercised their over-subscription rights based on the number of shares each stockholder subscribed for under such stockholder’s basic subscription rights. As a result, you may not receive any or all of the shares of common stock for which you exercise your over-subscription right.

As soon as practicable after the Expiration Date, the subscription agent will determine the number of shares of common stock that you may purchase pursuant to the over-subscription right. If you have properly exercised your over-subscription right, we will issue the shares of common stock purchased in the rights offering to you in book-entry, or uncertificated, form as soon as practicable after the Expiration Date and after all allocations and adjustments have been effected. If you request and pay for more shares than are allocated to you, we will refund the overpayment, without interest or deduction. In connection with the exercise of the over-subscription right, custodian banks, brokers, dealers and other nominee holders of subscription rights who act on behalf of beneficial owners will be required to certify to us and to the subscription agent as to the aggregate number of subscription rights exercised, and the number of shares requested through the over-subscription right, by each beneficial owner on whose behalf the nominee holder is acting.

The tax treatment of the rights offering may be treated as a taxable event to you.

We believe and intend to take the position that the distribution of the subscription rights in connection with the rights offering generally should not be a taxable event to holders of our common stock for U.S. federal income tax purposes. If the rights offering is deemed to be part of a “disproportionate distribution” under Section 305 of the Internal Revenue Code of 1986, as amended (the “Code”), holders of our common stock may recognize taxable income for U.S. federal income tax purposes in connection with the receipt of subscription rights in the rights offering. If you are a U.S. Person, see “Material U.S. Federal Income Tax Consequences” beginning on page S-43. You should consult your tax advisor as to the particular consequences to you of the rights offering, especially if you are not a U.S. Person.

We have broad discretion in the use of proceeds of the rights offering. Because our management will have broad discretion over the use of the net proceeds from the rights offering, you may not agree with how we use the proceeds, and we may not invest the proceeds successfully.

We currently intend to use the net proceeds from this offering to repay all amounts outstanding under the Note issued to Robert W. Duggan on April 20, 2021, further patient enrollment into the Ri-CoDIFy Phase 3 clinical trial program of ridinilazole, obtain regulatory approval of ridinilazole and prepare for its commercial launch, develop early-stage research projects using the Company’s Discuva Platform, pursue business development opportunities to expand our pipeline of drug candidates and support general corporate purposes. Our board of directors and management will have considerable discretion in the application of the net proceeds from the rights offering, and it is possible that we may allocate the proceeds differently than investors in the rights offering may desire or that we may fail to maximize the return on these proceeds. Accordingly, you will be relying on the judgment of our management with regard to the use of the proceeds from the rights offering, and you will not have the opportunity, as part of your investment decision, to assess whether the proceeds are being used appropriately. It is possible that the proceeds will be invested in a way that does not yield a favorable, or any, return for the Company.

Use of Proceeds

Although we cannot determine what the actual net proceeds from the sale of common stock in the rights offering will be until the rights offering is completed, assuming all subscription rights are exercised, we estimate that the aggregate net proceeds from the sale of the common stock, after deducting estimated offering expenses, will be approximately $74.5 million. We currently intend to use the net proceeds from this offering to repay all amounts outstanding under the Note issued to Robert W. Duggan on April 20, 2021, further patient enrollment into the Ri-CoDIFy Phase 3 clinical trial program of ridinilazole, obtain regulatory approval of ridinilazole and prepare for its commercial launch, develop early-stage research projects using the Company’s Discuva Platform, pursue business development opportunities to expand our pipeline of drug candidates and support general corporate purposes. As of the date of this prospectus supplement, we cannot specify with certainty all of the particular uses for the net proceeds to us from this offering. As a result, our management will have broad discretion regarding the timing and application of the net proceeds from this offering. Pending the uses described above, we intend to invest the net proceeds in interest-bearing, investment-grade securities.

Description of Capital Stock

The following description of our capital stock is intended as a summary only and therefore is not a complete description of our capital stock. This description is based upon, and is qualified by reference to, our restated certificate of incorporation, our amended and restated bylaws and applicable provisions of Delaware corporate law. You should read our restated certificate of incorporation and amended and restated bylaws, which are filed as exhibits to the registration statement of which this prospectus supplement forms a part, for the provisions that are important to you.

Our authorized capital stock consists of 250,000,000 shares of common stock, $0.01 par value per share and 20,000,000 shares of preferred stock, $0.01 par value per share. As of the Record Date, 82,926,705 shares of common stock were outstanding, and no shares of preferred stock were outstanding.

Common Stock

Annual Meeting. Annual meetings of our stockholders are held on the date designated in accordance with our by-laws. Written notice must be mailed to each stockholder entitled to vote not less than ten nor more than 60 days before the date of the meeting. The presence in person or by proxy of the holders of record of a majority of our issued and outstanding shares entitled to vote at such meeting constitutes a quorum for the transaction of business at meetings of the stockholders. Special meetings of the stockholders may be called for any purpose by the board of directors and shall be called by the secretary upon the written request, stating the purpose of such meeting, of the holders of at least twenty-five percent (25%) of the shares of capital stock entitled to vote in an election of directors. Except as may be otherwise provided by applicable law, our certificate of incorporation or our by-laws, all elections shall be decided by a plurality, and all other questions shall be decided by a majority, of the votes cast by stockholders entitled to vote thereon at a duly held meeting of stockholders at which a quorum is present.

Voting Rights. Each holder of common stock is entitled to one vote for each share held of record on all matters to be voted upon by stockholders.

Dividends. Subject to the rights, powers and preferences of any outstanding preferred stock, and except as provided by law or in our certificate of incorporation, dividends may be declared and paid or set aside for payment on the common stock out of legally available assets or funds when and as declared by the board of directors.

Liquidation, Dissolution and Winding Up. Subject to the rights, powers and preferences of any outstanding preferred stock, in the event of our liquidation, dissolution or winding up, our net assets will be distributed pro rata to the holders of our common stock.

Other Rights. Holders of the common stock have no right to:

The common stock does not have cumulative voting rights. Holders of shares of the common stock are not required to make additional capital contributions.

Transfer Agent and Registrar. Computershare Trust Company, N.A. is transfer agent and registrar for the common stock.

Preferred Stock

We are authorized to issue “blank check” preferred stock, which may be issued in one or more series upon authorization of our board of directors. Our board of directors is authorized to fix the designations, powers, preferences and the relative, participating, optional or other special rights and any qualifications, limitations and restrictions of the shares of each series of preferred stock. The authorized shares of our preferred stock are available for issuance without further action by our stockholders, unless such action is required by applicable law or the rules of any stock exchange on which our securities may be listed. If the approval of our stockholders is not required for the issuance of shares of our preferred stock, our board may determine not to seek stockholder approval.

Certain Provisions of Our Certificate of Incorporation and By-laws and Delaware Law

Board of Directors. All of our directors are elected annually. The number of directors comprising our board of directors is fixed from time to time by the board of directors.

Stockholder Nomination of Directors. Our by-laws provide that a stockholder must notify us in writing of any stockholder nomination of a director not earlier than the 120th day and not later than the 90th day prior to the first anniversary of the preceding year’s annual meeting; provided, that if the date of the annual meeting is advanced or delayed by more than 30 days from such anniversary date, notice by the stockholder to be timely must be so delivered not earlier than the 120th day prior to the date of such annual meeting and not later than the 90th day prior to the date of such meeting and (y) the 10th day following the day on which public announcement of the date of such annual meeting is first made by us.

Exclusive forum provision. Our restated certificate of incorporation provides that, unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware (or, if the Court of Chancery of the State of Delaware does not have jurisdiction, the federal district court for the District of Delaware) shall be the sole and exclusive forum for the following types of proceedings: (1) any derivative action or proceeding brought on behalf of our company, (2) any action asserting a claim of breach of a fiduciary duty owed by any of our directors, officers, employees or stockholders to our company or our stockholders, (3) any action asserting a claim arising pursuant to any provision of the General Corporation Law of the State of Delaware or as to which the General Corporation Law of the State of Delaware confers jurisdiction on the Court of Chancery of the State of Delaware, or (4) any action asserting a claim arising pursuant to any provision of our restated certificate of incorporation or amended and restated bylaws (in each case, as they may be amended from time to time) or governed by the internal affairs doctrine. These choice of forum provisions will not apply to suits brought to enforce a duty or liability created by the Exchange Act. Furthermore, Section 22 of the Securities Act creates concurrent jurisdiction for federal and state courts over all such Securities Act actions. Accordingly, both state and federal courts have jurisdiction to entertain such claims. To prevent having to litigate claims in multiple jurisdictions and the threat of inconsistent or contrary rulings by different courts, among other considerations, our certificate of incorporation provides that, unless we consent in writing to the selection of an alternative forum, the federal district courts of the United States of America shall, to the fullest extent permitted by law, be the sole and exclusive forum for the resolution of any claims arising under the Securities Act. While the Delaware courts have determined that such choice of forum provisions are facially valid, a stockholder may nevertheless seek to bring a claim in a venue other than those designated in the exclusive forum provisions. In such instance, we would expect to vigorously assert the validity and enforceability of the exclusive forum provisions of our restated certificate of incorporation. This may require significant additional costs associated with resolving such action in other jurisdictions and there can be no assurance that the provisions will be enforced by a court in those other jurisdictions.

Dilution

Our net tangible book value as of December 31, 2020 was approximately $65.9 million, or $0.79 per share of our common stock. Net tangible book value per share is equal to our total net tangible book value, which is our total tangible assets less our total liabilities, divided by the number of shares of our outstanding common stock. Dilution per share equals the difference between the amount per share paid by purchasers of shares of common stock that are sold in the rights offering and the net tangible book value per share of our common stock immediately after the rights offering.

After giving effect to the assumed sale of 14,312,977 shares of our common stock in the rights offering, based on the assumed subscription price of $5.24 per shares of common stock (the Initial Price), and after deducting estimated offering expenses payable by us, our pro forma net tangible book value as of December 31, 2020 would have been approximately $140.4 million, or $1.44 per share. This represents an immediate increase in pro forma net tangible book value to existing stockholders of $0.65 per share and an immediate dilution to purchasers in the rights offering of $3.80 per share.

The following table illustrates this per-share dilution (assuming the rights offering is fully subscribed at the assumed subscription price of $5.24 per share of common stock) (the Initial Price). To the extent that the Alternate Price is lower than the Initial Price, purchasers of our common stock in the rights offering will experience further dilution.

The information above is illustrative only and will adjust based on the actual subscription price and the actual number of shares of common stock sold in the rights offering. The number of shares to be outstanding after this rights offering is based on 82,919,522 shares of common stock outstanding as of March 31, 2021 and excludes:

To the extent that any options or warrants are exercised, new options are issued under our equity incentive plans or we otherwise issue additional shares of common stock in the future at a price less than the public offering price, there will be further dilution to new investors.

The Rights Offering

Subscription Rights

Basic Subscription Rights

We will distribute to each holder of our common stock who is a record holder of our common stock on the record date, which is April 9, 2021 at no charge, one non-transferable subscription right for every one share of common stock owned. The subscription rights will be evidenced by non-transferable subscription rights certificates. Each subscription right will entitle the rights holder to purchase 0.172598 shares of common stock at the Initial Price, which shall be paid in cash, upon timely delivery of the required documents and payment of the subscription price. To the extent that the Alternate Price is lower than the Initial Price, we will sell additional shares of common stock, but we will not sell fractional shares. If rights holders wish to exercise their subscription rights, they must do so prior to 5:00 p.m., Eastern Time, on May 10, 2021, the Expiration Date for the rights offering, subject to extension. After the Expiration Date, the subscription rights will expire and will have no value. See below “—Expiration of the Rights Offering and Extensions, Amendments and Termination.” You are not required to exercise all of your subscription rights. We will issue to the record holders who purchase shares of common stock in the rights offering the shares in book-entry, or uncertificated, form as soon as practicable after the rights offering has expired.

Over-Subscription Rights

Subject to the allocation described below, each subscription right also grants the holder an over-subscription right to purchase additional shares of common stock that are not purchased by other rights holders pursuant to their basic subscription rights. You are entitled to exercise your over-subscription right only if you exercise your basic subscription right in full.

If you wish to exercise your over-subscription right, you should indicate the number of additional shares of common stock that you would like to purchase in the space provided on your rights certificate, as well as the number of shares that you beneficially own without giving effect to any shares to be purchased in this rights offering. When you send in your rights certificate, you must also send the full purchase price, as provided herein, for the number of additional shares of common stock that you have requested to purchase (in addition to the payment, as provided herein, due for shares of common stock purchased through your basic subscription right). If the number of shares of common stock remaining after the exercise of all basic subscription rights is not sufficient to satisfy all requests for shares pursuant to over-subscription rights, you will be allocated additional shares in the proportion which the number of shares you purchased through the basic subscription right bears to the total number of shares that all oversubscribing stockholders purchased through the basic subscription right. The subscription agent will return any excess payments in the form in which made.

As soon as practicable after the Expiration Date, the subscription agent will determine the number of shares of common stock that you may purchase pursuant to the over-subscription right. If you request and pay for more shares than are allocated to you, we will refund the overpayment in the form in which made. In connection with the exercise of the over-subscription right, custodian banks, brokers, dealers and other nominee holders of subscription rights who act on behalf of beneficial owners will be required to certify to us and to the subscription agent as to the aggregate number of subscription rights exercised, and the number of shares of common stock requested through the over-subscription right, by each beneficial owner on whose behalf the nominee holder is acting.

Subscription Price

The subscription price per share of common stock will be the lesser of (i) $5.24 (the “Initial Price”) and (ii) the volume weighted average price of our common stock for the ten (10) consecutive trading days through and including the Expiration Date (the “Alternate Price”). Subscribers must fund their subscriptions pursuant to both the basic subscription right and over-subscription right at the Initial Price.

In determining the subscription price, our board of directors, with the advice and input of management and advisors, considered a number of factors, including: the likely cost of capital from other sources and general conditions of the securities markets, the price at which our stockholders might be willing to participate in the rights offering, historical and current trading prices for our common stock, our need for liquidity and capital, and the desire to provide an opportunity to our stockholders to participate in the rights offering on a pro rata basis. The subscription price is not necessarily related to our book value, net worth or any other established criteria of value and may or may not be considered the fair value of our common stock to be offered in the rights offering. You should not consider the subscription price as an indication of value of us or our common stock. The market price of our common stock may decline during or after the rights offering, including below the subscription price for the common stock in the rights offering. You should obtain a current quote for our common stock before exercising your subscription rights and make your own assessment of our business and financial condition, our prospects for the future, and the terms of the rights offering.

Expiration of the Rights Offering and Extensions, Amendments and Termination

You may exercise your subscription rights at any time prior to 5:00 p.m., Eastern Time, on May 10, 2021, the Expiration Date for the rights offering. If you do not exercise your subscription rights before the Expiration Date of the rights offering, your subscription rights will expire and will have no value. We will not be required to sell shares of common stock to you if the subscription agent receives your rights certificate or payment, after the Expiration Date, regardless of when you sent the rights certificate and payment.

We may, in our sole discretion, extend the time for exercising the subscription rights. We may extend the Expiration Date at any time after the record date. If the commencement of the rights offering is delayed for a period of time, the Expiration Date of the rights offering may be similarly extended. We will extend the duration of the rights offering as required by applicable law, and may choose to extend the duration of the rights offering for any reason. We may extend the Expiration Date of the rights offering by giving oral or written notice to the subscription agent on or before the scheduled Expiration Date. If we elect to extend the Expiration Date of the rights offering, we will issue a press release announcing such extension no later than 9:00 a.m., Eastern Time, on the next business day after the most recently announced Expiration Date.

We reserve the right, in our sole discretion, to amend or modify the terms of the rights offering. We also reserve the right to terminate the rights offering at any time prior to the Expiration Date for any reason, in which event all funds received in connection with the rights offering will be returned without interest or deduction to those persons who exercised their subscription rights as soon as practicable.

Calculation of Subscription Rights Exercised; Missing or Incomplete Subscription Information

If you do not indicate the number of subscription rights being exercised, or do not forward full payment of the total subscription price payment for the number of subscription rights that you indicate are being exercised, then you will be deemed to have exercised your subscription rights with respect to the maximum number of whole shares of common stock that may be exercised with the aggregate subscription price payment you delivered to the subscription agent. If your aggregate subscription price payment is greater than the amount you owe for exercise of your basic subscription right in full, you will be deemed to have exercised your over-subscription right to purchase the maximum number of shares with your over-payment.

If an insufficient number of shares of common stock is available to fully satisfy all over-subscription right requests, the available shares will be distributed proportionately among rights holders who exercise their oversubscription right based on the number of shares each rights holder subscribed for under the basic subscription right. The proration process will be repeated until all shares of common stock have been allocated or all oversubscription exercises have been fulfilled, whichever occurs earlier. Any excess subscription payments received by the subscription agent caused by proration will be returned by the subscription agent to you by mail, without interest or penalty, as soon as practicable after the Expiration Date of the rights offering. The subscription agent will return any excess payments in the form in which it was made. Any Excess Subscription Amount resulting from the reduction of the subscription price from the Initial Price to the Alternate Price will be put towards the purchase of additional shares of common stock (either towards your basic subscription right, if available, or towards the over-subscription right if you have already exercised your basic subscription right in full).

No Fractional Shares

We will not issue fractional shares of common stock in the rights offering. Rights holders will only be entitled to purchase a whole number of shares of common stock, rounded down to the nearest whole number of shares a holder would otherwise be entitled to purchase. Any Excess Subscription Amount resulting from the reduction of the subscription price from the Initial Price to the Alternate Price will be put towards the purchase of additional shares of common stock (either towards your basic subscription right, if available, or towards the over-subscription right if you have already exercised your basic subscription right in full). The excess amount for any fractional shares of common stock will be returned to you as soon as practicable, in the form in which made. You will not receive interest or a deduction on any payments refunded to you under the rights offering.

Conditions to the Rights Offering

We may terminate the rights offering, in whole or in part, if at any time before completion of the rights offering there is any judgment, order, decree, injunction, statute, law or regulation entered, enacted, amended or held to be applicable to the rights offering that in the sole judgment of our board of directors would or might make the rights offering or its completion, whether in whole or in part, illegal or otherwise restrict or prohibit completion of the rights offering. We may waive any of these conditions and choose to proceed with the rights offering even if one or more of these events occur. If we terminate the rights offering, in whole or in part, all affected subscription rights will expire without value and all subscription payments in the form in which received by the subscription agent will be returned in the form in which paid, without interest or deduction, as soon as practicable. See also “—Expiration of the Rights Offering and Extensions, Amendments and Termination.”

Method of Exercising Subscription Rights

The exercise of subscription rights is irrevocable and may not be cancelled or modified. Your subscription rights will not be considered exercised unless the subscription agent receives from you, your custodian bank, broker, dealer or nominee, as the case may be, all of the required documents properly completed and executed and your full subscription price payment in cash, as provided herein, prior to the Expiration Date of the rights offering, which is currently set to be 5:00 p.m., Eastern Time, on May 10, 2021. Rights holders may exercise their rights as follows:

Subscription by Registered Holders

Rights holders who are registered holders of our common stock as of the record date may exercise their subscription right by properly completing and executing the rights certificate together with any required signature guarantees and forwarding it, together with payment in full, as provided herein, of the subscription price for each share of common stock for which they subscribe, to the subscription agent at the address set forth under the subsection titled “—Delivery of Subscription Materials and Payment,” on or prior to the Expiration Date.

Subscription by DTC Participants

Banks, trust companies, securities dealers and brokers (each, a “Nominee”) that hold shares of our common stock on the Record Date as nominee for more than one beneficial owner may, upon proper showing to the subscription agent, exercise such beneficial owner’s subscription right through DTC on the same basis as if the beneficial owners were stockholders on the Record Date. Such Nominee may exercise the subscription right on behalf of the exercising beneficial owner through DTC’s PSOP Function on the “agents subscription over PTS” procedure by (1) providing a certification as to the aggregate number of subscription rights exercised by the beneficial owner on whose behalf such Nominee is acting, and (2) instructing DTC to charge the Nominee’s applicable DTC account for the subscription payment for the new shares of common stock to facilitate the delivery of the full subscription payment to the subscription agent. DTC must receive the subscription instructions and payment for the new shares of common stock no later than the Expiration Date.

Subscription by Beneficial Owners

Rights holders who are beneficial owners of shares of our common stock as of the record date and whose shares are registered in the name of a custodian bank, broker, dealer or other nominee, or would prefer to have an institution conduct the transaction relating to the rights on their behalf, should instruct their custodian bank, broker, dealer or other nominee or institution to exercise their rights and deliver all documents and payment, on their behalf, prior to the Expiration Date. A rights holder’s subscription rights will not be considered exercised unless the subscription agent receives from such rights holder or the rights holder’s custodian bank, broker, dealer, or other nominee or institution, as the case may be, all of the required documents and such holder’s full subscription price payment.

Method of Payment

You must timely pay the full subscription price, in U.S. currency, for the full number of shares of common stock at the Initial Price you wish to acquire pursuant to the exercise of rights (including any exercise of the over-subscription rights, if available) by delivering:

Rights certificates received after the Expiration Date of the rights offering will not be honored, and we will return your payment to you in the form received as soon as practicable, without interest or deduction. The subscription agent will not accept uncertified personal checks, bank drafts or cashier’s checks as a means of payment.

The subscription agent will be deemed to receive payment upon:

If, on the Expiration Date, the Alternate Price is lower than the Initial Price, any Excess Subscription Amounts paid by a subscriber will be put towards the purchase of additional shares of common stock.

Instructions for Completing Your Subscription Rights Certificate

You should read the instruction letter accompanying the rights certificate carefully and strictly follow it. DO NOT SEND RIGHTS CERTIFICATES OR PAYMENTS TO THE COMPANY. We will not consider your subscription received until the subscription agent has received delivery of a properly completed and duly executed rights certificate and payment of the full subscription amount. The risk of delivery of all documents and payments is on you or your nominee, not us or the subscription agent.

The method of delivery of rights certificates and payment of the subscription amount to the subscription agent will be at the risk of the holders of rights, but, if sent by mail, we recommend that you send those certificates and payments by overnight courier or by registered mail, properly insured, with return receipt requested, and that a sufficient number of days be allowed to ensure delivery to the subscription agent and clearance of payment before the expiration of the subscription period.

Unless a rights certificate provides that the shares of common stock are to be delivered to the record holder of such rights or such certificate is submitted for the account of a bank or a broker, signatures on such rights certificate must be guaranteed by an “Eligible Guarantor Institution,” as such term is defined in Rule 17Ad-15 of the Securities Exchange Act of 1934 (an “Eligible Institution”), subject to any standards and procedures adopted by the subscription agent. See “—Medallion Guarantee May Be Required.”

Medallion Guarantee May Be Required

If you completed any part of the subscription rights certificate to provide that the common stock purchased pursuant to your exercise of Subscription Rights were to be (x) issued in a name other than that of the registered holder, or (y) issued to an address other than that shown on the front of the subscription rights certificate, your signature on each subscription rights certificate must be guaranteed by an Eligible Institution, such as a member firm of a registered national securities exchange or a member of the Financial Industry Regulatory Authority, Inc., or a commercial bank or trust company having an office or correspondent in the United States, or by a member of a Stock Transfer Association approved medallion program such as STAMP, SEMP or MSP subject to standards and procedures adopted by the subscription agent.

Subscription and Information Agent

The subscription agent and information agent for this rights offering is Broadridge Corporate Issuer Solutions, Inc. We will pay all fees and expenses of Broadridge related to the rights offering and have also agreed to indemnify Broadridge from certain liabilities that it may incur in connection with the rights offering. Broadridge can be contacted at the following address and telephone number:

Broadridge Corporate Issuer Solutions, Inc.
Attn: BCIS Re-Organization Dept.
P.O. Box 1317
Brentwood, NY 11717-0718
Toll Free: 1-855-793-5068

Delivery of Subscription Materials and Payment

You should deliver your subscription rights certificate and payment of the subscription price, as provided herein, or, if applicable, nominee holder certifications, to the subscription agent by one of the methods described below:

Your delivery to an address or by any method other than as set forth above will not constitute valid delivery and we may not honor the exercise of your subscription rights.

You should direct any questions or requests for assistance concerning the method of subscribing for shares of common stock or for additional copies of this prospectus supplement to the information agent.

Funding Arrangements; Return of Funds

Broadridge Corporate Issuer Solutions, Inc., the subscription agent, will hold funds received in payment for shares of common stock in a segregated account pending completion of the rights offering. The subscription agent will hold this money until the rights offering is completed or is withdrawn or terminated. If the rights offering is canceled for any reason, all subscription payments received by the subscription agent will be returned to subscribers, without interest or penalty, as soon as practicable.

Guaranteed Delivery

There is no guaranteed delivery period in connection with this rights offering, so you must ensure that you properly complete all required steps prior to 5:00 p.m., Eastern Time, on May 10, 2021, unless we decide to extend the rights offering Expiration Date until some later time or terminate it earlier.

Notice to Beneficial Holders

If you are a broker, a trustee or a depositary for securities who holds shares of our common stock for the account of others as of the record date, you should notify the respective beneficial owners of such shares of the rights offering as soon as possible to find out their intentions with respect to exercising their subscription rights. You should obtain instructions from the beneficial owners with respect to their subscription rights, as set forth in the instructions we have provided to you for your distribution to beneficial owners. If a beneficial owner so instructs, you should complete the appropriate subscription rights certificates and submit them to the subscription agent with the proper payment. If you hold shares of our common stock for the account(s) of more than one beneficial owner, you may exercise the number of subscription rights to which all such beneficial owners in the aggregate otherwise would have been entitled had they been direct record holders of our common stock on the record date, provided that you, as a nominee record holder, make a proper showing to the subscription agent by submitting the form entitled “Nominee Holder Certification” substantially in the form accompanying this prospectus supplement. If you did not receive this form, you should contact the subscription agent to request a copy.

Beneficial Owners

If you are a beneficial owner of shares of our common stock or will receive subscription rights through a custodian bank, broker, dealer or other nominee, we will ask your custodian bank, broker, dealer or other nominee to notify you of the rights offering. If you wish to exercise your subscription rights, you will need to have your custodian bank, broker, dealer or other nominee act for you. If you hold shares of our common stock directly under your name in stock certificate(s) or in book-entry, or uncertificated, form, but would prefer to have your custodian bank, broker, dealer or other nominee act for you, you should contact your nominee and request it to effect the transactions for you. Your nominee may establish a deadline prior to the Expiration Date by which you must provide it with your instructions to exercise your subscription rights and payment for your shares.

To indicate your decision with respect to your subscription rights, you should complete and return to your custodian bank, broker, dealer or other nominee the form entitled “Beneficial Owners Election Form” substantially in the form accompanying this prospectus supplement. You should receive the “Beneficial Owners Election Form” from your custodian bank, broker, dealer or other nominee with the other rights offering materials. If you wish to obtain a separate subscription rights certificate, you should contact the nominee as soon as possible and request that a separate subscription rights certificate be issued to you. You should contact your custodian bank, broker, dealer or other nominee if you do not receive this form but you believe you are entitled to participate in the rights offering. We are not responsible if you do not receive this form from your custodian bank, broker, dealer or nominee or if you receive it without sufficient time to respond.

Determinations Regarding the Exercise of Your Subscription Rights

We will decide all questions concerning the timeliness, validity, form and eligibility of the exercise of your subscription rights and any such determinations by us will be final and binding. We, in our sole discretion, may waive, in any particular instance, any defect or irregularity, or permit, in any particular instance, a defect or irregularity to be corrected within such time as we may determine. We will not be required to make uniform determinations in all cases. We may reject the exercise of any of your subscription rights because of any defect or irregularity. We will not accept any exercise of subscription rights until all irregularities have been waived by us or cured by you within such time as we decide, in our sole discretion. Our interpretations of the terms and conditions of the rights offering will be final and binding. Neither we, nor the subscription agent, will be under any duty to notify you of any defect or irregularity in connection with your submission of subscription rights certificates and we will not be liable for failure to notify you of any defect or irregularity. We reserve the right to reject your exercise of subscription rights if your exercise is not in accordance with the terms of the rights offering or in proper form. We will also not accept the exercise of your subscription rights if our sale of common stock to you could be deemed unlawful under applicable law.

No Revocation or Change

Once you submit the form of rights certificate to exercise any subscription rights, you may not revoke or change your exercise or request a refund of monies paid. All exercises of rights are irrevocable, even if you subsequently learn information about us that you consider to be unfavorable. You should not exercise your rights unless you are certain that you wish to purchase additional shares of common stock at the Initial Price.

Non-Transferability of the Rights

The subscription rights granted to you are non-transferable and, therefore, may not be assigned, gifted, purchased, sold or otherwise transferred to anyone else. Notwithstanding the foregoing, you may transfer your rights as required by operation of law; for example, a transfer of rights to the estate of the recipient upon the death of the recipient would be permitted. If the rights are transferred as permitted, evidence satisfactory to us that the transfer was proper must be received by us prior to the Expiration Date.

Issuance of Common Stock

All shares of our common stock that you purchase in the rights offering will be issued in book-entry, or uncertificated, form, meaning that you will receive a direct registration (DRS) account statement from our transfer agent reflecting ownership of these securities if you are a holder of record of shares or warrants. If you hold your shares of common stock in the name of a custodian bank, broker, dealer, or other nominee, DTC will credit your account with your nominee with the securities you purchased in the Rights Offering. Subject to state securities laws and regulations, we have the discretion to delay distribution of any securities you may have elected to purchase by exercise of your rights in order to comply with state securities laws.

Validity of Subscriptions

We will resolve all questions regarding the validity and form of the exercise of your subscription rights, including time of receipt and eligibility to participate in the rights offering. Our determination will be final and binding. Once made, subscriptions and directions are irrevocable, and we will not accept any alternative, conditional or contingent subscriptions or directions. We reserve the absolute right to reject any subscriptions or directions not properly submitted or the acceptance of which would be unlawful. You must resolve any irregularities in connection with your subscriptions before the subscription period expires, unless waived by us in our sole discretion. Neither the subscription agent nor we shall be under any duty to notify you or your representative of defects in your subscriptions. A subscription will be considered accepted, subject to our right to cancel the rights offering, only when a properly completed and duly executed subscription rights certificate and any other required documents and payment of the full subscription amount have been received by the subscription agent and any defects or irregularities therein waived by us. Our interpretations of the terms and conditions of the rights offering will be final and binding.

Rights of Subscribers

You will have no rights as a holder of the shares of our common stock you purchase in the rights offering until shares are issued in book-entry form or your account at your broker, dealer, bank or other nominee is credited with the shares of our common stock purchased in the rights offering. You will have no right to revoke your subscriptions after you deliver your completed rights certificate, subscription payment, as provided herein, and any other required documents to the subscription agent.

Foreign Stockholders and Stockholders with Army Post Office or Fleet Post Office Addresses

The subscription agent will not mail rights certificates to you if you are a stockholder whose address is outside the United States or if you have an Army Post Office or a Fleet Post Office address. Instead, we will have the subscription agent hold the subscription rights certificates for your account. To exercise your rights, you must notify the subscription agent prior to 11:00 a.m., Eastern Time, at least three (3) business days prior to the Expiration Date, and establish to the satisfaction of the subscription agent that it is permitted to exercise your subscription rights under applicable law. If you do not follow these procedures by such time, your rights will expire and will have no value.

No Board of Directors Recommendation

An investment in the Company’s common stock must be made according to your evaluation of your own best interests and after considering all of the information herein, including the section titled “Risk Factors” beginning on page S-24 of this prospectus supplement. Neither we nor our board of directors are making any recommendation regarding whether you should exercise your subscription rights.

Purchase Commitments

Robert W. Duggan has indicated that he intends to exercise at least all of his basic subscription rights, but has not made any formal binding commitment to do so.

Shares of Common Stock Outstanding After the Rights Offering

The number of shares of our common stock that will be outstanding after the rights offering will depend on the number of shares of common stock that are purchased in the rights offering. Assuming no additional shares of common stock are issued by us prior to consummation of the rights offering and assuming all offered shares of common stock are sold in the rights offering at the Initial Price, we will issue approximately 14,312,977 shares of common stock. In that case, we will have approximately 97,239,682 shares of common stock outstanding after the rights offering. This would represent an increase of approximately 17% in the number of outstanding shares of common stock. To the extent that the Alternate Price is lower than the Initial Price, we will sell additional shares of common stock in the rights offering, and the number of shares of common stock outstanding after the rights offering will accordingly be higher.

Fees and Expenses

Neither we, nor the subscription agent, will charge a brokerage commission or a fee to subscription rights holders for exercising their rights. However, if you exercise your subscription rights through a custodian bank, broker, dealer or nominee, you will be responsible for any fees charged by your custodian bank, broker, dealer or nominee.

Questions About Exercising Subscription Rights

If you have any questions or require assistance regarding the method of exercising your subscription rights or requests for additional copies of this document or any document mentioned herein, you should contact the subscription agent at the address and telephone number set forth above under “— Delivery of Subscription Materials and Payment.”

No “Going Private” Transaction

The rights offering is not a transaction or series of transactions which has either a reasonable likelihood or a purpose of producing a “going private effect” as specified in Rule 13e-3 of the Exchange Act. Given the structure of the rights offering, as described in this prospectus supplement, the Company will continue to be registered pursuant to Section 12 of the Exchange Act and intends to remain listed on the Nasdaq Global Market following completion of the rights offering.

Other Matters

The Company is not making the rights offering in any state or other jurisdiction in which it is unlawful to do so, nor is the Company distributing or accepting any offers to purchase any of our securities from subscription rights holders who are residents of those states or of other jurisdictions or who are otherwise prohibited by federal or state laws or regulations to accept or exercise the subscription rights. The Company may delay the commencement of the rights offering in those states or other jurisdictions, or change the terms of the rights offering, in whole or in part, in order to comply with the securities law or other legal requirements of those states or other jurisdictions. Subject to state securities laws and regulations, the Company also has the discretion to delay allocation and distribution of any securities you may elect to purchase by exercise of your subscription rights in order to comply with state securities laws. The Company may decline to make modifications to the terms of the rights offering requested by those states or other jurisdictions, in which case, if you are a resident in one of those states or jurisdictions or if you are otherwise prohibited by federal or state laws or regulations from accepting or exercising the subscription rights you will not be eligible to participate in the rights offering.

Material U.S. Federal Income Tax Consequences

The following is a summary of the material U.S. federal income tax consequences of the receipt, exercise and expiration of the subscription rights and the ownership and disposition of our common stock acquired upon exercise of the subscription rights. This summary is based upon the provisions of the Code, Treasury Regulations promulgated thereunder, administrative rulings and judicial decisions, all as of the date hereof. These authorities may be changed or subject to differing interpretations, possibly with retroactive effect, so as to result in U.S. federal income tax consequences different from those set forth below. We have not sought and will not seek any ruling from the Internal Revenue Service (“IRS”) with respect to the statements made and the conclusions reached in the following summary, and there can be no assurances that the IRS or a court will agree with such statements and conclusions.

This summary does not purport to be a complete analysis of all the potential tax considerations relating to the subscription rights. In addition, this summary does not address the tax consideration arising under the laws of any U.S. state or local or any non-U.S. jurisdiction, estate or gift tax, the 3.8% Medicare tax on net investment income or any alternative minimum tax consequences. In addition, this discussion only applies to U.S. Persons (as defined below) and does not address tax considerations applicable to a holder’s particular circumstances or to a holder that may be subject to special tax rules, including, without limitation:

In addition, if a partnership, including any entity or arrangement classified as a partnership for U.S. federal income tax purposes, holds any subscription right, the tax treatment of a partner will generally depend on the status of the partner, the activities of the partnership and certain determinations made at the partner level. Accordingly, partnerships that hold any subscription right, and partners in such partnerships, should consult their tax advisors regarding the U.S. federal income tax consequences to them of the receipt, exercise and expiration of the subscription rights and the ownership and disposition of our common stock acquired upon exercise of the subscription rights.

You are urged to consult your tax advisor with respect to the application of the U.S. federal income tax laws to your particular situation, as well as any tax consequences arising under the U.S. federal estate or gift tax rules or under the laws of any U.S. state or local or any non-U.S. or other taxing jurisdiction or under any applicable tax treaty.

For purposes of this discussion, a “U.S. Person” means a beneficial owner of any subscription right that is:

EACH HOLDER OF SHARES OF OUR COMMON STOCK IS STRONGLY URGED TO CONSULT SUCH HOLDER’S OWN TAX ADVISORS REGARDING THE SPECIFIC FEDERAL, STATE, LOCAL AND NON-U.S. INCOME AND OTHER TAX CONSIDERATIONS OF THE RECEIPT AND EXERCISE OF THE SUBSCRIPTION RIGHTS AND THE OWNERSHIP AND DISPOSITION OF OUR COMMON STOCK ACQUIRED UPON EXERCISE OF THE SUBSCRIPTION RIGHTS.

U.S. Federal Income Tax Considerations Applicable to the Receipt of Subscription Rights

Receipt of Subscription Rights

Although the authorities governing transactions such as this rights offering are complex and do not speak directly to the consequences of certain aspects of this rights offering or the distribution of subscription rights and the effects of the over-subscription right, we do not believe your receipt of subscription rights pursuant to the rights offering should be treated as a taxable distribution with respect to your existing shares of our common stock for U.S. federal income tax purposes. Pursuant to Section 305(a) of the Code, in general, the receipt by a stockholder of a right to acquire stock should not be included in the taxable income of the recipient. The general rule of non-recognition in Section 305(a) of the Code is subject to exceptions in Section 305(b) of the Code, which include “disproportionate distributions.” A disproportionate distribution is a distribution or a series of distributions, including deemed distributions, that has the effect of the receipt of cash or other property by some stockholders or holders of debt instruments convertible into stock and an increase in the proportionate interest of other stockholders in a corporation’s assets or earnings and profits. During the last 36 months, we have not made any distributions of cash or non-stock property with respect to our common stock. In addition, within the last 36 months, we have not made any distributions of cash or non-stock property on previously outstanding convertible notes. Currently we do not intend to make any future distributions of cash or non-stock property with respect to our common stock or to issue any convertible debt, and we do not intend to redeem, otherwise terminate for cash or make any other adjustments to any award under any of our equity compensation plans; however, there is no guarantee that we will not take any of the foregoing actions in the future. Further, the fact that we may have outstanding options and warrants could cause, under certain circumstances that cannot currently be predicted (such as a failure to properly adjust the option price in connection with a stock distribution), the receipt of subscription rights pursuant to this rights offering to be part of a disproportionate distribution, as contemplated in Section 305(b) of the Code.

Our position regarding the tax-free treatment of the subscription rights distribution is not binding on the IRS or the courts. If this position is finally determined by the IRS or a court to be incorrect, whether on the basis that the issuance of the subscription rights is a “disproportionate distribution” or otherwise, the fair market value of the subscription rights will be taxable to holders of our common stock as a dividend to the extent of the holder’s pro rata share of our current and accumulated earnings and profits, if any. Any excess will be treated as a return of capital to the extent thereof and then as capital gain. Although no assurance can be given, it is anticipated that we will not have current and accumulated earnings and profits through the end of 2021.

The following discussion is based upon the treatment of the subscription rights issuance as a non-taxable distribution with respect to your existing shares of our common stock for U.S. federal income tax purposes.

Tax Basis in the Subscription Rights

If the fair market value of the subscription rights you receive is less than 15% of the fair market value of your existing shares of our common stock (with respect to which the subscription rights are distributed) on the date you receive the subscription rights, the subscription rights will be allocated a zero dollar basis for U.S. federal income tax purposes, unless you elect to allocate your basis in your existing shares of our common stock between your existing shares of our common stock and the subscription rights in proportion to the relative fair market values of the existing shares of our common stock and the subscription rights, determined on the date of receipt of the subscription rights. If you choose to allocate basis between your existing shares of our common stock and the subscription rights, you must make this election on a statement included with your timely filed tax return (including extensions) for the taxable year in which you receive the subscription rights. Such an election is irrevocable.

However, if the fair market value of the subscription rights you receive is 15% or more of the fair market value of your existing shares of our common stock on the date you receive the subscription rights, then you must allocate your basis in your existing shares of our common stock between those shares and the subscription rights you receive in proportion to their fair market values determined on the date you receive the subscription rights.

The fair market value of the subscription rights on the date that the subscription rights are distributed is uncertain, and we have not obtained, and do not intend to obtain, an appraisal of the fair market value of the subscription rights on that date. In determining the fair market value of the subscription rights, you should consider all relevant facts and circumstances, including any difference between the subscription price of the subscription rights and the trading price of our shares of common stock on the date that the subscription rights are distributed, the length of the period during which the subscription rights may be exercised and the fact that the subscription rights are non-transferable.

Holders of shares of our common stock should consult with their own tax advisors regarding their tax basis in shares of our common stock and subscription rights received.

Exercise of Subscription Rights

Generally, you will not recognize gain or loss upon the exercise of a subscription right acquired in the rights offering. Your initial tax basis in our common stock acquired pursuant to the exercise of a subscription right will equal the subscription price you pay, plus the tax basis, if any, in the subscription right you exercised, determined as described above. The holding period of shares of our common stock acquired upon exercise of a subscription right in the rights offering will begin on the date of exercise.

If you exercise a subscription right received in the rights offering after disposing of the shares of our common stock with respect to which such subscription right is received, then certain aspects of the tax treatment of the exercise of the subscription right are unclear, including (i) the allocation of the tax basis between the shares of our common stock previously sold and the subscription right, (ii) the impact of such allocation on the amount and timing of gain or loss recognized with respect to the shares of our common stock previously sold and (iii) the impact of such allocation on the tax basis of the shares of our common stock acquired upon exercise of the subscription right. Furthermore, if you exercise the subscription rights and sell other shares of our common stock within the 61-day period beginning 30 days before the exercise date and ending 30 days after the exercise date, the “wash sale” rules may disallow the recognition of any loss upon the sale of our common stock. If you exercise a subscription right received in the rights offering after disposing of shares of our common stock with respect to which the subscription right is received or within 30 days before disposing of shares of our common stock, you should consult with your own tax advisor.

Expiration of Subscription Rights

If you allow subscription rights received in the rights offering to expire, you should not recognize any gain or loss for U.S. federal income tax purposes, and you should re-allocate any portion of the tax basis in your existing common stock previously allocated to the subscription rights that have expired to the existing common stock.

U.S. Federal Income Tax Considerations Applicable to Our Common Shares

Distributions

Distributions with respect to shares of our common stock acquired upon exercise of subscription rights will be taxable as dividend income when actually or constructively received to the extent of our current or accumulated earnings and profits as determined for U.S. federal income tax purpose.

Dividend income received by certain non-corporate holders with respect to shares of our common stock generally will be “qualified dividends” subject to preferential rates of U.S. federal income tax, provided that the holder meets applicable holding period and other requirements. Subject to similar exceptions for short-term and hedged positions, dividend income on our shares of common stock paid to holders that are domestic corporations generally will qualify for the dividends-received deduction. To the extent that the amount of a distribution exceeds our current and accumulated earnings and profits, such distribution will be treated first as a tax-free return of capital to the extent of your adjusted tax basis in such shares of our common stock and thereafter as capital gain.

Dispositions

A holder that sells or otherwise disposes of shares of common stock acquired upon exercise of subscription rights in a taxable transaction will generally recognize capital gain or loss equal to the difference between the amount realized and such holder’s adjusted tax basis in the shares. Such capital gain or loss will be long-term capital gain or loss if a holder’s holding period for such shares is more than one year at the time of disposition. Long-term capital gain of a non-corporate holder is generally taxed at preferential rates. The deductibility of capital losses is subject to limitations.

Information Reporting and Backup Withholding

You may be subject to information reporting and backup withholding with respect to the gross proceeds from the disposition of shares of our common stock acquired through the exercise of subscription rights or dividend payments. Backup withholding (currently at the rate of 24%) may apply under certain circumstances if you (i) fail to furnish a correct social security or other taxpayer identification number, or TIN, (ii) fail to report interest or dividends properly or (iii) fail to provide a certified statement, signed under penalty of perjury, that the TIN provided is correct, that you are not subject to backup withholding and that you are a U.S. Person for U.S. federal income tax purposes on IRS Form W-9. Any amount withheld from a payment under the backup withholding rules is allowable as a credit against (and may entitle you to a refund with respect to) your U.S. federal income tax liability, provided that the required information is timely furnished to the IRS. Certain persons are exempt from information reporting and backup withholding, including corporations and certain financial institutions, provided that they demonstrate this fact, if requested. You are urged to consult your own tax advisor as to your qualification for exemption from backup withholding and the procedure for obtaining such exemption.

AS INDICATED ABOVE, THE FOREGOING DISCUSSION IS FOR GENERAL INFORMATION PURPOSES ONLY AND SHOULD NOT BE VIEWED AS COMPLETE OR COMPREHENSIVE TAX ADVICE. HOLDERS RECEIVING A DISTRIBUTION OF SUBSCRIPTION RIGHTS CONTEMPLATED IN THIS RIGHTS OFFERING AND HOLDERS CONSIDERING THE PURCHASE OF OUR COMMON STOCK BY EXERCISING SUCH SUBSCRIPTION RIGHTS ARE URGED TO CONSULT THEIR OWN TAX ADVISORS REGARDING THE APPLICATION OF THE U.S. FEDERAL TAX LAWS TO THEIR PARTICULAR SITUATIONS AND THE APPLICABILITY AND EFFECT OF STATE, LOCAL AND NON-U.S. LAWS TO THEM.

Plan of Distribution

We are distributing rights certificates and copies of this prospectus supplement to those persons who were holders of our common stock on April 9, 2021, the record date for the rights offering, promptly following the effective date of the registration statement of which this prospectus supplement forms a part. We have not employed any brokers, dealers or underwriters in connection with the solicitation or exercise of rights in the rights offering and no commissions, fees or discounts will be paid in connection with the rights offering. While certain of our directors, officers and other employees may solicit responses from you, those directors, officers and other employees will not receive any commissions or compensation for their services other than their normal compensation, and will not register with the SEC as brokers in reliance on certain safe harbor provisions contained in Rule 3a4-1 under the Exchange Act.

Delivery of Subscription Rights

As soon as practicable after the record date for the rights offering, we will distribute the rights, rights certificates and copies of this prospectus supplement to individuals who owned shares of common stock on 5:00 p.m., Eastern Time, on April 9, 2021. If your shares are held in the name of a custodian bank, broker, dealer or other nominee, then you should send your subscription documents and subscription payment to that record holder. If you are the record holder, then you should send your subscription documents, rights certificate, and subscription payment to the subscription agent, Broadridge Corporate Issuer Solutions, Inc., at the following address. If sent by mail, we recommend that you send documents and payments by registered mail, properly insured, with return receipt requested, and that a sufficient number of days be allowed to ensure delivery to the subscription agent. Do not send or deliver these materials to the Company.

In the event that the rights offering is not fully subscribed, holders of rights who exercise all of their rights pursuant to their basic subscription right will have the opportunity to subscribe for additional shares of common stock pursuant to the over-subscription right. See further the section titled “The Rights Offering” beginning on page S-32.

We have not agreed to enter into any standby or other arrangement to purchase or sell any rights or any of our securities. Robert W. Duggan has indicated that he intends to exercise at least all of his basic subscription rights, but has not made any formal binding commitment to do so.

We have not entered into any agreements regarding stabilization activities with respect to our securities. If you have any questions, you should contact the information agent at Broadridge Corporate Issuer Solutions, Inc., Attn: BCIS Re-Reorganization Dept., P.O. Box 1317, Brentwood, NY 11717-0718, by telephone at 1-855-793-5068 or by email at shareholder@broadridge.com. We have agreed to pay Broadridge Corporate Issuer Solutions, Inc. a fee plus certain expenses, which we estimate will total approximately $40,000. We estimate that our total expenses in connection with the rights offering will be approximately $500,000.

Other than as described herein, we do not know of any existing agreements between any stockholder, broker, dealer, underwriter or agent relating to the sale or distribution of the shares of common stock.

Legal Matters

The validity of the rights and shares of common stock offered by this prospectus supplement have been passed upon for us by Olshan Frome Wolosky LLP.

Experts

The financial statements incorporated in this prospectus by reference to the Annual Report on Form 10-K for the year ended December 31, 2020 have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting. The registered business address of PricewaterhouseCoopers LLP is 3 Forbury Place, 23 Forbury Road, Reading, England, RG1 3JH.

Incorporation by Reference

The SEC allows us to incorporate by reference into this prospectus supplement certain information we file with it, which means that we can disclose important information by referring you to those documents. The information incorporated by reference is considered to be a part of this prospectus supplement, and information that we file later with the SEC will automatically update and supersede information contained in this prospectus supplement. We incorporate by reference the documents listed below that we have previously filed with the SEC (excluding any portions of any Form 8-K that are not deemed “filed” pursuant to the General Instructions of Form 8-K):

All documents we file pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act on or after the date of this prospectus supplement and before all of the securities offered by this prospectus supplement are sold are incorporated by reference in this prospectus supplement from the date of filing of the documents, except for information furnished and not deemed “filed” pursuant to the General Instructions of Form 8-K, which is not deemed filed and not incorporated by reference herein. Information that we file with the SEC will automatically update and may replace information in this prospectus supplement and information previously filed with the SEC.

This prospectus supplement may contain information that updates, modifies or is contrary to information in one or more of the documents incorporated by reference in this prospectus supplement. You should rely only on the information incorporated by reference or provided in this prospectus supplement or the accompanying prospectus. We have not authorized anyone else to provide you with different information. You should not assume that the information in this prospectus supplement is accurate as of any date other than the date of this prospectus supplement or the date of the documents incorporated by reference in this prospectus supplement.

We will provide to each person, including any beneficial owner, to whom this prospectus supplement is delivered, upon written or oral request, at no cost to the requester, a copy of any and all of the information that is incorporated by reference in this prospectus supplement.

Requests for such documents should be directed to:

Summit Therapeutics Inc.
One Broadway, 14^th Floor
Cambridge, MA 02142
Attention: Chief Financial Officer

You may also access certain of the documents incorporated by reference in this prospectus supplement through our website at www.summittxinc.com. Except for the specific incorporated documents listed above, no information available on, or that can be accessed through, our website shall be deemed to be incorporated by reference into this prospectus supplement or the registration statement of which it forms a part.

Where You Can Find Additional Information

We file annual, quarterly and other reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov. Our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, and Current Reports on Form 8-K, including any amendments to those reports, and other information that we file with or furnish to the SEC pursuant to Section 13(a) or 15(d) of the Exchange Act can also be accessed free of charge through the Internet. These filings will be available as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC.

We have filed with the SEC a registration statement under the Securities Act of 1933 (the “Securities Act”) relating to the offering of these securities. The registration statement, including the attached exhibits, contains additional relevant information about us and the securities. This prospectus supplement does not contain all of the information set forth in the registration statement. You can obtain a copy of the registration statement, at prescribed rates, from the SEC at the address listed above. The registration statement and the documents referred to below under “Information Incorporated by Reference” are also available on our website, www.summittxinc.com. We have not incorporated by reference into this prospectus supplement the information on, or that can be accessed through, our website, and it is not a part of this prospectus supplement, and the inclusion of our website address is an inactive textual reference only.

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