AI-native drug developer Chai Discovery closed a $130 million Series B at a $1.3 billion valuation to accelerate its computational platform for therapeutic design. The financing, led by Oak HC/FT and General Catalyst with participation from OpenAI-linked investors, follows a recently released preprint claiming Chai’s models can design monoclonal antibodies with drug-like properties. Chai said the cash will fund model development, expand molecule design throughput and advance partnerships with pharma. The company also added former Pfizer CSO Mikael Dolsten to its board, signaling stronger biotech-pharma ties as computational design tools move toward de-risking early discovery. AI-driven design here refers to generative models trained to propose protein sequences and structures; such models aim to reduce time and cost of lead identification. Investors continue to reward AI-native biotechs that demonstrate reproducible, preclinical or translational outputs.