Galapagos NV has entered into a binding agreement with Gilead Sciences to collaborate on advancing a first-in-class T cell engager program for autoimmune diseases, centered on the drug candidate gamgertamig.

The agreement is linked to Gilead’s planned $1.675 billion acquisition of Ouro Medicines, with additional milestone payments of up to $500 million. Under the deal, Galapagos will fund 50% of the upfront and milestone costs while gaining access to key intellectual property and operational assets, including Ouro’s research platform.

Gamgertamig, currently in Phase 1/2 studies, has shown strong early efficacy and safety in severe autoimmune conditions such as autoimmune hemolytic anemia and immune thrombocytopenia, and could enter late-stage trials as early as 2027.

The collaboration also provides Galapagos with greater financial flexibility, including control over at least $500 million in cash for independent strategic initiatives and potential shareholder returns. Gilead will lead global commercialization, paying tiered royalties to Galapagos upon market launch.

The companies said the partnership aims to accelerate development of innovative immune therapies targeting high unmet medical needs.