Chai Discovery, a Biotech Company Backed by OpenAI, Raises $130M Series B at $1.3B Valuation

Chai Discovery, a biotechnology startup backed by OpenAI, announced on Monday it has secured $130 million in Series B funding, achieving a $1.3 billion valuation.

The round was co-led by General Catalyst and Oak HC/FT, with participation from Menlo Ventures, OpenAI, Dimension, Thrive Capital, Neo, Yosemite Venture Fund, Lachy Groom, SV Angel, and new investors Glade Brook and Emerson Collective. This brings the company’s total funding to over $225 million.

Chai operates in a rapidly expanding field that views artificial intelligence as a pivotal force in accelerating drug development. In August, Menlo Ventures led Chai’s $70 million Series A round, positioning the startup as a developer of foundational AI models for drug discovery—specifically focused on predicting interactions between biochemical molecules so they can be reprogrammed for therapeutic use.

The company aims to “build a CAD-like toolkit for molecular design.” Last year, it introduced its Chai 1 AI model and has now unveiled Chai 2, which demonstrates significant improvements in the successful design of novel antibodies. This advancement enables the creation of fully custom antibodies from scratch, rather than relying on modifications of existing ones.

“Our latest models can generate molecules with desired drug properties and tackle targets that have historically been difficult to address,” said Josh Meier, co-founder and CEO of Chai, in a prepared statement.