Chai Discovery

Chai Discovery builds frontier AI foundation models to predict and reprogram interactions between biochemical molecules for drug discovery. Its Chai-1 model, released as open source in 2024, performs molecular structure prediction at the state of the art, and its later models advanced de novo antibody design; commercial work now centers on the Chai-3 model, with pharma partnerships including Pfizer, Eli Lilly, and Novartis. Founded in 2024 by CEO Joshua Meier (previously at Absci, Meta AI, and OpenAI), president Jack Dent (formerly an engineering and product leader at Stripe), and researchers Matthew McPartlon and Jacques Boitreaud, the company is based in San Francisco; former Pfizer chief scientific officer Mikael Dolsten sits on its board. Chai raised a $400M Series C in July 2026 led by Index Ventures at a $3.8B valuation, following a $130M Series B in December 2025 and bringing total funding to roughly $630M.