Investing.com -- Gilead Sciences Inc. announced Monday 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.

The acquisition will cost Gilead $1.675 billion in upfront cash consideration, subject to customary adjustments, plus up to $500 million in contingent milestone payments.

The deal adds OM336 (gamgertamig), a clinical-stage BCMAxCD3 T cell engager, to Gilead's inflammation portfolio. OM336, which has gotten both Fast Track and Orphan Drug Designation, is designed to enable rapid B cell depletion following subcutaneous treatment. In ongoing Phase 1/2 clinical studies, the drug has shown efficacy in severe autoimmune diseases including autoimmune hemolytic anemia and immune thrombocytopenia.

Gilead plans to enter into a strategic collaboration with Galapagos on the Ouro portfolio. Under the proposed arrangement, Galapagos would pay 50% of the upfront consideration and milestone payments, absorb substantially all of Ouro's operating assets and retain its employees. Galapagos would be responsible for development costs through initiation of registrational studies, with subsequent costs shared equally between the parties.

Gilead would retain sole worldwide commercialization rights, except in Greater China where Keymed Biosciences has existing rights, and would pay Galapagos royalties of 20% to 23% of net sales.

The collaboration would also amend the legacy Galapagos Option License and Collaboration Agreement to allow up to $500 million of Galapagos' current cash to be used freely, including up to $150 million for potential share repurchases.

This is Gilead's second major deal within a month. In February of 2026, Gilead announced it has entered into a definitive agreement to acquire Arcellx for $115 per share in cash at closing and one contingent value right of $5 per share, which represents an implied equity value of $7.8 billion payable at closing. Arcellx is a biotechnology company focused on delivering immunotherapies for patients with cancer and other diseases.