OpenAI-backed biotech company Chai Discovery raises $130M Series B at $1.3B valuation

Chai Discovery, a biotech startup backed by OpenAI, announced a $130 million Series B round at a valuation of $1.3 billion on Monday.

The round was led by General Catalyst and Oak HC/FT, the company said. Other participants include: Menlo Ventures, OpenAI, Dimension, Thrive Capital, Neo, Yosemite Venture Fund, Lachy Groom, SV Angel, and new investors Glade Brook and Emerson Collective. The company’s total funding now stands at more than $225 million.

The company is one of a growing industry that sees artificial intelligence as a faster path to drug development. In August, Menlo Ventures announced it was leading a $70 million Series A round for Chai. The investor described Chai as a startup that was building fundamental models tuned for drug discovery, specifically to predict interactions between biochemical molecules so they could be reprogrammed for therapeutics.

Zhai says his ambition is to “build a computer-aided design suite for molecules.” Last year, the startup announced the Chai 1 AI model and is now introducing the Chai 2, its latest model. The company says Chai 2 achieves significant improvements in success rates compared to other methods of de novo antibody design, which means building custom antibodies from scratch, not modifying existing antibodies.

“Our latest models can design molecules that have properties we want from actual drugs, addressing challenging targets that have been out of reach,” Josh Mayer, co-founder and CEO of CHAI, said in a prepared statement.

Previously, Mayer, whose background is in machine learning, worked in research and engineering at Facebook, and before that, at OpenAI, according to his LinkedIn. The profile indicates that Chai Discovery was founded in 2024.