8-K

Date: May 28, 2021

PROTHENA CORPORATION PLC

/s/ Tran B. Nguyen

Tran B. Nguyen

Chief Operating Officer and Chief Financial Officer

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 28, 2021

PROTHENA CORPORATION PUBLIC LIMITED COMPANY

(Exact name of registrant as specified in its charter)


Ireland	001-35676	98-1111119
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(IRS Employer Identification No.)

77 Sir John Rogerson’s Quay, Block C

Grand Canal Docklands

Dublin 2, D02 VK60, Ireland

(Address of principal executive offices, including Zip Code)

Registrant’s telephone number, including area code: 011-353-1-236-2500

(Former Name or Former Address, if Changed Since Last Report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:


Title of Each Class	Trading Symbol	Name of Each Exchange on Which Registered
Ordinary Shares, par value $0.01 per share	PRTA	The Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 8.01. Other Events.

Prothena Corporation plc (the “Company” or “Prothena”), a late-stage clinical company with a robust pipeline of novel investigational therapeutics built on protein dysregulation expertise, announced today that it has exercised its rights under the terms of the ongoing worldwide collaboration with Roche (the “Worldwide Collaboration”) to receive potential U.S. commercial sales milestones and tiered royalties in lieu of a U.S. profit and loss share for prasinezumab in Parkinson’s disease.

The change in participation was preceded by an evaluation by the Company, which included an estimated net present value analyses of multiple scenarios. This change in participation does not affect Prothena’s rights and obligations outside the United States. As part of its second quarter 2021 financial results, the Company plans to provide an update detailing the projected reduction in net cash used in operating and investing activities resulting from this election.

Prothena is committed to the development of prasinezumab, the first anti-alpha synuclein antibody to advance into late-stage clinical development and will remain a member of the Joint Steering Committee under the Worldwide Collaboration.

***

This Current Report on Form 8-K contains forward-looking statements. These statements relate to, among other things, amounts we might receive under our collaboration with Roche; the treatment potential, design, and proposed mechanism of action of prasinezumab; and plans for future clinical studies of prasinezumab. These statements are based on estimates, projections, and assumptions that may prove not to be accurate, and actual results could differ materially from those anticipated due to known and unknown risks, uncertainties and other factors, including but not limited to the effects on our business of the worldwide COVID-19 pandemic and the risks, uncertainties, and other factors described in the “Risk Factors” section of our Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) on May 11, 2021, as well as discussions of potential risks, uncertainties, and other important factors in our subsequent filings with the SEC. We undertake no obligation to update publicly any forward-looking statements contained in this Form 8-K as a result of new information, future events, or changes in our expectations.