Gilead Sciences to acquire Ouro Medicines for $1.675 billion upfront, with up to $500 million in milestones, to advance OM336 (gamgertamig), a BCMAxCD3 bispecific T‑cell engager for severe autoimmune diseases. Galapagos NV in advanced talks to co‑fund development and share future royalties.
Written By: Karthik Teja Macharla, PharmD
Reviewed By: Pharmacally Editorial Team
Gilead Sciences has entered into a definitive agreement to acquire privately held biotechnology company Ouro Medicines in a deal valued at $1.675 billion upfront, with an additional $500 million in potential milestone payments, for a total transaction value of up to approximately $2.18 billion. The acquisition strengthens Gilead’s position in next‑generation immune therapies and is focused on OM336 (gamgertamig), a clinical‑stage BCMAxCD3 bispecific T‑cell engager being developed for severe autoimmune diseases.
OM336 is designed to enable rapid and deep depletion of B cells and plasma cells through a limited course of subcutaneous treatment. The therapy works by redirecting a patient’s own T cells toward BCMA‑expressing plasma cells, which are responsible for producing pathogenic autoantibodies in several immune‑mediated disorders. This targeted approach aims to suppress disease‑driving immune activity while potentially enabling durable remission without long‑term immunosuppression, positioning gamgertamig as a first‑in‑class T‑cell engager program for autoimmune diseases.
Early clinical data from ongoing Phase 1/2 studies have shown promising activity in severe antibody‑mediated orphan diseases, including autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP). After a single treatment cycle, gamgertamig has demonstrated transformative efficacy along with a differentiated safety profile, supporting continued development. The therapy has received both Fast Track and Orphan Drug Designation from the U.S. FDA for AIHA and ITP and is expected to move into registrational studies in 2027.
Galapagos partnership and financial terms
Alongside the acquisition, Galapagos NV and Gilead are engaged in advanced discussions to expand their collaboration around the Ouro Medicines assets. Under the proposed structure, Galapagos would contribute 50% of the $1.675 billion upfront acquisition cost and 50% of the potential $500 million milestone payments and would absorb the operating assets and employees of Ouro Medicines to advance development activities. Development costs for OM336 would be funded by Galapagos until registrational trials begin, after which both companies would share expenses.
If finalized, Gilead would retain global commercialization rights for gamgertamig, except in Greater China, where Keymed Biosciences holds existing rights. Galapagos would receive royalties ranging from 20% to 23% of net sales. The collaboration would also modify the companies’ existing Option, License and Collaboration Agreement, allowing Galapagos to use up to $500 million of its current cash independently for research and development initiatives outside the original framework.
The proposed Galapagos partnership is contingent on the closing of the Gilead–Ouro transaction, and both companies expect to finalize the collaboration structure in parallel with the regulatory review process.
Henry Gosebruch, CEO of Galapagos, said Galapagos is encouraged by the emerging clinical profile of gamgertamig, describing it as a “promising lead program” for immune‑mediated diseases and noting that the discussions with Gilead mark an important step in the company’s strategic transformation.
Jaideep Dudani, PhD, CEO of Ouro Medicines, said gamgertamig has the potential to redefine treatment for autoimmune diseases, adding that multiple trials are already underway and that support from Gilead and Galapagos could help accelerate its development.
Dietmar Berger, MD, PhD, Chief Medical Officer of Gilead Sciences, highlighted the promise of BCMA‑targeted T‑cell engagers as a new approach for severe autoimmune diseases by eliminating pathogenic plasma cells that drive disease activity.
The transaction between Gilead and Ouro Medicines remains subject to regulatory clearances and customary closing conditions. If successful, gamgertamig could represent a new class of targeted immune therapies aimed at delivering deep, durable control of antibody‑driven autoimmune disorders, with the expanded Gilead–Galapagos partnership providing a coordinated pathway to registrational studies and potential global commercialization.
Reference
Gilead Sciences to Acquire Ouro Medicines to Advance First in Class T Cell Engager Program for Autoimmune Diseases, 23 March 2026, Gilead Sciences, Inc. – Gilead Sciences to Acquire Ouro Medicines to Advance First in Class T Cell Engager Program for Autoimmune Diseases
Galapagos and Gilead in Advanced Discussions to Collaborate on Advancing First in Class T Cell Engager Program for Autoimmune Diseases, 23 March 2026, Galapagos and Gilead in Advanced Discussions to Collaborate on Advancing First in Class T Cell Engager Program for Autoimmune Diseases – Galapagos
Gilead Sciences to Acquire Ouro Medicines to Advance First in Class T Cell Engager Program for Autoimmune Diseases, 23 March 2026, https://www.ouromedicines.com/news/032326/
About the Writer
Karthik Teja Macharla, PharmD is a Pharm.D. graduate with a strong interest in clinical research, pharmacovigilance, and medical writing. In his words, he is passionate about converting complex medical information into clear, evidence-based scientific communication, committed to contributing to patient safety and advancing healthcare through accurate and impactful medical content.