Gilead Sciences will acquire autoimmune drugmaker Ouro Medicines, the companies said Monday afternoon, spending nearly $1.7 billion on the young startup and a T cell engager it licensed from a Chinese biotechnology firm.
Ouro launched in early 2025, backed by GSK and Monograph Capital. Its bispecific antibody, called OM336 or gamgertamig, is designed to bind to a pair of immune cell proteins, BCMA and CD3, that have been popular targets for drugmakers.
Many bispecific antibodies have been approved for cancers, but over the past decade, a flurry of research has shown these treatments hold promise in autoimmune diseases as well. The multipronged drugs eliminate B cells much like cell therapies, but cost less to manufacture, don’t require harsh chemotherapy conditioning and can be dosed multiple times.
OM336 is in clinical testing for several uncommon conditions such as autoimmune cytopenias, where the body attacks healthy blood cells; bullous diseases, where the immune system goes after a layer of skin tissue; idiopathic inflammatory myopathy, which affects muscles; and Sjögren’s syndrome, which targets certain glands.
Biotechs like Ouro are not only setting out to prove next-generation bispecifics’ value in immune disease, but also their abilities to spare healthy tissues and sidestep toxic side effects like cytokine release syndrome — a type of overactive immune response.
Gilead follows a line of startups and established drugmakers that have poured billions into developing T cell engagers. Last week, two newer biotechs, Excalipoint Therapeutics and Crossbow Therapeutics, banked venture capital funds to further test their multispecific antibodies. GSK, Merck & Co. and Bristol Myers Squibb have all acquired promising next-generation T cell engagers for cancer and immune diseases.
“This novel framework complements our expanding inflammation pipeline and reflects our strategy to invest in innovative science that may redefine standards of care,” said Dietmar Berger, Gilead’s chief medical officer, in a statement.
Gilead has made a handful of other investments in drugs for inflammatory diseases in recent years, acquiring a small U.K. company called MiroBio and striking up partnerships with Arcus Biosciences and Kyverna Therapeutics.
Gilead on Monday also said it was finalizing a research collaboration with partner Galapagos, handing the latter “substantially all” of Ouro's assets and employees in exchange for help financing half the deal. The two companies would develop OM336 together, though Gilead would retain commercialization rights in most of the world and pay Galapagos as much as 23% in possible royalties.
OM336, which was initially developed by Keymed Medicines, is also in development for a type of multiple myeloma in China. Keymed, which holds a 15% stake in Ouro, will receive about $250 million as a result of the acquisition.
If the drug hits certain research, development and commercial milestones, Gilead could spend as much as $500 million in additional payouts to Ouro’s shareholders.
