Chai Discovery, an AI-native drug discovery company, today announced it has raised $130 million in a Series B financing, valuing the company at $1.3 billion. The round was co-led by Oak HC/FT and General Catalyst, with participation from existing investors including OpenAI, Thrive Capital, Menlo Ventures, and Dimension. This funding brings Chai’s total capital raised to over $225 million, less than two years after emerging from stealth mode.

Just months ago, Chai completed a $70 million Series A and launched Chai-2, a generative platform designed to transform drug discovery. The platform replaces slow, iterative experimentation with a computational design process capable of moving directly from a biological target to a viable drug candidate. Chai-2 operates a “zero-shot” model, generating novel antibody sequences from scratch based solely on a target, without relying on prior examples or extensive screening. The approach has reportedly achieved double-digit experimental success rates in antibody design, representing a “100-fold improvement” over previous computational methods.

“We’re standing on the precipice of a new era for the biopharmaceutical industry,” said Josh Meier, CEO of Chai Discovery.

Chai’s approach treats biology as an information problem. The company builds large-scale AI models to predict and reprogram interactions between biochemical molecules, including proteins, antibodies, nucleic acids, and small molecules. These interactions are fundamental to nearly all biological processes, and the ability to target them with precision opens new avenues for therapeutics against complex pathways that have historically resisted conventional drug development.

Many of today’s most pressing medical challenges lie in aging and chronic, age-related diseases, where biological targets are complex or poorly understood. Conditions such as neurodegeneration, metabolic disease, fibrosis, and immune dysfunction involve molecular interactions that have been difficult to modulate safely and effectively. By enabling the rational design of novel antibodies and other biologics against these targets, Chai’s platform aims to support the development of next-generation therapies that address the underlying biology of aging, rather than merely managing symptoms.