Gilead Acquires Ouro Medicines for $1.675 Billion, Targeting Autoimmune Diseases

Gilead Sciences signed a definitive agreement to acquire Ouro Medicines, a privately held biotechnology company focused on developing T cell engager therapies for autoimmune diseases. The price: $1,675 million in upfront cash consideration, subject to customary adjustments, payable at closing, and up to $500 million in contingent milestone payments.

The acquisition adds OM336, known by its clinical name 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. What makes the asset compelling is the early data: 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 and immune thrombocytopenia.

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. OM336 is in-licensed by Ouro Medicines from Keymed Biosciences, which owns the rights to develop the program in Greater China.

Gilead's chief medical officer framed the deal in explicitly strategic terms. "This acquisition underscores our commitment to advancing transformative therapies for people living with serious autoimmune diseases," said Dietmar Berger, MD, PhD. "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."

Jaideep Dudani, PhD, co-founder and CEO of Ouro Medicines, said the company "saw the potential for gamgertamig to redefine the standard of care for immune-mediated diseases" from the outset, adding that with Gilead and Galapagos's support, Ouro could "build on the strong early foundation — leveraging a proven track record in late stage development, launch, and commercialization."

The deal arrives with a built-in development partner already identified. Under the contemplated collaboration, Galapagos would absorb substantially all of Ouro's operating assets and retain all Ouro employees, while Galapagos and Gilead would collaborate on the development of OM336, with Galapagos responsible for development costs through initiation of registrational studies and registrational study costs shared equally between the parties. Gilead would retain sole worldwide commercialization rights, other than in Greater China where Keymed Biosciences holds existing commercialization rights, and would pay Galapagos royalties of 20% to 23% of net sales.

The Ouro deal is Gilead's second major acquisition within a month. In February 2026, Gilead announced a definitive agreement to acquire Arcellx for $115 per share in cash plus one contingent value right of $5 per share, representing an implied equity value of $7.8 billion. That deal targeted myeloma therapies; the Ouro acquisition pushes the same T cell engager technology into autoimmune territory.

Centerview Partners and TD Cowen are acting as financial advisors to Gilead; Goldman Sachs served as exclusive financial advisor to Ouro Medicines; and Morgan Stanley advised Galapagos. Closing remains subject to expiration or termination of applicable regulatory filings and other customary conditions, with the 2027 registrational study timeline serving as the next major clinical test of whether the $1.675 billion upfront price holds up.