OpenAI-Backed Chai Discovery Raises $130M to Tackle “Undruggable” Targets with Generative AI

Chai Discovery has raised $130 million in Series B financing, boosting the company’s valuation to $1.3 billion just months after emerging from stealth. The round was co-led by Oak HC/FT and General Catalyst, with backing from OpenAI, Thrive Capital, Menlo Ventures, and other major investors. The funding reflects strong confidence in Chai’s proprietary AI models, which can predict biochemical interactions and design new drugs—including candidates for targets long considered “undruggable.”

Chai aims to overhaul the traditional drug-development paradigm, historically defined by decade-long timelines and billion-dollar price tags. Its generative and predictive AI systems are built to compress scientific cycles from years to weeks by modeling and reprogramming interactions between biological molecules. CEO Josh Meier said problems that looked like five-year challenges are now being solved in weeks thanks to Chai’s rapid progress. The company’s newest platform, Chai 2, is a zero-shot generative model that has achieved double-digit experimental success in de novo antibody design—representing a 100-fold improvement over previous computational methods.

The company’s focus extends beyond simply identifying potential molecules: its AI is engineered to optimize “developability,” ensuring that designed drugs are not only theoretically effective but also viable for real-world use in human biology. This approach enables Chai to pursue disease targets that have traditionally been out of reach because they couldn’t be addressed with conventional small molecules or biologics.

Chai’s governance will expand with the addition of Annie Lamont (Oak HC/FT) and Hemant Taneja (General Catalyst) to its board. Both leaders described drug development as a critical arena for AI transformation, with Chai positioned to build a “computer-aided design suite” for therapeutics—what could eventually become the standard operating system for biopharma R&D. With more than $225 million raised to date, the company plans to accelerate development of its models and platform infrastructure to scale programmable drug discovery.