-- Acquisition Adds Clinical Stage Bispecific BCMAxCD3 T Cell Engager with Potential for Durable Immune Reset to Gilead's Inflammation Portfolio --

-- Gilead Intends to Enter into a Strategic Collaboration with Galapagos on the Ouro Portfolio of Medicines --

Gilead Sciences, Inc. (NASDAQ:GILD) announced today it has entered into a definitive agreement to acquire Ouro Medicines, a privately held biotechnology company focused on developing T cell engager therapies for autoimmune diseases.

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The acquisition adds OM336 (gamgertamig), a clinical‑stage BCMAxCD3 T cell engager, to Gilead's growing inflammation portfolio. OM336 is designed to enable rapid and deep B cell depletion following a limited subcutaneously administered treatment course. In ongoing Phase 1/2 clinical studies, OM336 has demonstrated transformative efficacy and a differentiated safety profile after a single treatment cycle in severe antibody-mediated orphan diseases including autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP). Gamgertamig has been granted both Fast Track and Orphan Drug Designation by the U.S. FDA for the treatment of AIHA and ITP and is expected to enter registrational studies in 2027.

"This acquisition underscores our commitment to advancing transformative therapies for people living with serious autoimmune diseases," said Dietmar Berger, MD, PhD, Chief Medical Officer of Gilead. "BCMA is a validated target with emerging data demonstrating potentially transformative outcomes in autoimmune diseases. BCMA targeted T cell engagers represent a differentiated approach with the potential to induce durable disease control. This novel framework complements our expanding inflammation pipeline and reflects our strategy to invest in innovative science that may redefine standards of care."

BCMA‑targeted T cell engagers are being investigated as a precision approach for severe inflammatory and autoimmune diseases by eliminating pathogenic B cells and plasma cells. By redirecting a patient's own T cells toward BCMA‑expressing plasma cells, clinical data suggests these agents may reduce inflammation, improve organ‑level disease, and, in some cases, enable an immune reset marked by durable, drug‑free remission without ongoing immunosuppression. T cell engagers represent an important modality for patients alongside Gilead's portfolio of CAR-T assets.

"From the outset, we saw the potential for gamgertamig to redefine the standard of care for immune-mediated diseases," said Jaideep Dudani, PhD, CoFounder and Chief Executive Officer of Ouro Medicines. "Since then, we've taken meaningful steps to advance that vision, with multiple trials now underway. With support from Gilead and Galapagos, we can build on the strong early foundation—leveraging a proven track record in late stage development, launch, and commercialization to accelerate our programs and help deliver on the promise gamgertamig holds for patients with immune-mediated diseases, following our initial collaboration with Keymed Biosciences."

Terms of the Transaction

Under the terms of the agreement Gilead will acquire all of the outstanding equity of Ouro Medicines for a total of $1,675 million in upfront cash consideration, subject to customary adjustments, which is payable at closing, and up to $500 million in contingent milestone payments. Closing of the transaction is subject to expiration or termination of certain regulatory filings and other customary conditions.

Strategic Collaboration with Galapagos

Gilead is currently in advanced discussions with Galapagos with respect to a potential research and development collaboration on the acquired Ouro Medicines assets. The arrangement between Gilead and Galapagos is contemplated to include the following key terms:

Galapagos would pay 50% of the upfront consideration and 50% of any contingent milestone payments payable to Ouro Medicines' shareholders.
Galapagos would absorb substantially all of Ouro Medicines' operating assets and retain its employees.
Gilead and Galapagos would collaborate on the development of OM336, with Galapagos responsible for development costs through initiation of registrational studies. Registrational study costs would be shared equally between the parties.
Gilead would retain sole worldwide commercialization rights (other than in Greater China where Keymed Biosciences has existing commercialization rights) and Gilead would pay Galapagos royalties of 20%-23% of net sales.
Amended legacy Galapagos Option License and Collaboration Agreement ("OLCA") to allow for up to $500 million of Galapagos' current cash to be used freely by Galapagos, including up to $150 million for potential share repurchases.

Centerview Partners LLC and TD Cowen are acting as financial advisors to Gilead. Goldman Sachs & Co. LLC is acting as the exclusive financial advisor to Ouro Medicines. Morgan Stanley & Co., LLC is acting as financial advisor to Galapagos. Covington & Burling LLP, Mayer Brown LLP, and Arnold & Porter Kaye Scholer LLP are serving as legal counsel to Gilead. Goodwin Procter LLP is serving as legal counsel to Ouro Medicines. Paul Weiss LLP and Linklaters LLP are serving as legal counsel to Galapagos.

About OM336

OM336 is an investigational BCMAxCD3 bispecific T cell engager for the treatment of autoantibodies driven immune-mediated disease. OM336 has been granted Orphan Drug Designation and Fast Track Designation by the U.S. Food and Drug Administration for certain autoimmune diseases. OM336 is under an open IND in the U.S. and is expected to enter registrational studies in 2027. OM336 is in-licensed by Ouro Medicines from Keymed Biosciences, which owns the rights to develop the program in Greater China.

About Gilead Sciences

Gilead Sciences, Inc. is a biopharmaceutical company that has pursued and achieved breakthroughs in medicine for more than three decades, with the goal of creating a healthier world for all people. The company is committed to advancing innovative medicines to prevent and treat life-threatening diseases, including HIV, viral hepatitis, COVID-19, cancer, and inflammation. Gilead operates in more than 35 countries worldwide, with headquarters in Foster City, Calif.

About Ouro Medicines

Ouro Medicines is a clinical stage biotechnology company dedicated to developing immune reset therapeutics for people living with chronic immune-mediated diseases. Ouro's approach is focused on leveraging T cell engagers in B cell-mediated diseases to achieve immune resets that create durable remissions without ongoing immunosuppression. Based in San Francisco and launched in 2025, Ouro was founded by Monograph Capital in partnership with GSK. Ouro is also backed by leading investors TPG, NEA and Norwest. For more information visit www.ouromedicines.com or follow us on LinkedIn.

Gilead Forward-Looking Statements

This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that are subject to risks, uncertainties and other factors, including the ability of Gilead and Ouro Medicines to complete the acquisition transaction in a timely manner or at all; the possibility that various closing conditions for the acquisition transaction may not be satisfied or waived, including the possibility that a governmental entity may prohibit, delay or refuse to grant approval for the consummation of the acquisition transaction; uncertainties relating to the timing or outcome of any filings and approvals relating to the acquisition transaction; the ability of Gilead to negotiate and enter into the proposed collaboration with Galapagos, including on the terms described herein and in a timely manner or at all; difficulties or unanticipated expenses in connection with integrating the companies, including the effects of the acquisition transaction and the proposed collaboration on relationships with employees, other business partners or governmental entities; the risk that Gilead may not realize the expected benefits of this acquisition transaction; the ability of Gilead to advance their product pipeline and successfully commercialize product candidates following the acquisition; the ability of the parties to initiate and complete clinical trials involving such product candidates in the currently anticipated timelines or at all; the possibility of unfavorable results from one or more of such trials involving such product candidates; uncertainties relating to regulatory applications and related filing and approval timelines, including the risk that FDA may not approve any such product candidates in the anticipated indications or on the timelines or at all, and any marketing approvals, if granted, may have significant limitations on its use;; and any assumptions underlying any of the foregoing. These and other risks, uncertainties and other factors are described in detail in Gilead's Annual Report on Form 10-K for the year ended December 31, 2025, as filed with the U.S. Securities and Exchange Commission. These risks, uncertainties and other factors could cause actual results to differ materially from those referred to in the forward-looking statements. All statements other than statements of historical fact are statements that could be deemed forward-looking statements. The reader is cautioned that any such forward-looking statements are not guarantees of future performance and involve risks and uncertainties and is cautioned not to place undue reliance on these forward-looking statements. All forward-looking statements are based on information currently available to Gilead, and Gilead assumes no obligation and disclaims any intent to update any such forward-looking statements.

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For more information about Gilead, please visit the company's website at www.gilead.com, follow Gilead on X/Twitter (@Gilead Sciences) and LinkedIn (@Gilead-Sciences).

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Gilead Contacts:

Jessica Smith, Media

public_affairs@gilead.com

Jacquie Ross, Investors

investor_relations@gilead.com

Ouro Medicines Contact:

FGS Global

ouro@fgsglobal.com

Gilead Sciences to Acquire Ouro Medicines to Advance First in Class T Cell Engager Program for Autoimmune Diseases