Chai Discovery signed a license agreement with Pfizer to deploy its AI-driven drug discovery platform within Pfizer's research and development operations.

The agreement marks one of the first major pharmaceutical deployments of Chai's technology.

What does Chai's platform do?

Chai’s generative AI software is designed to predict and reprogram interactions between molecules, enabling scientists to design biomolecules with specific functional properties from scratch.¹ The company says its models can compress discovery timelines that traditionally took months or years into short experimental sprints by tackling hard-to-drug targets and accelerating early-stage development cycles.

"By combining Chai's frontier AI platform with Pfizer's scientific depth, data and discovery capabilities, we see an opportunity to expand and accelerate what is possible in biologics discovery and help Pfizer pursue targets that traditional methods have struggled to reach," said Joshua Meier, co-founder of Chai Discovery.

What is Chai-3?

Chai-3 represents a step forward from its predecessor in AI-driven antibody design, doubling the success rate of the prior model and producing antibodies that meet required therapeutic standards.¹ The model advances capabilities in therapeutic binding, multi-specific molecule design, and improved generalization across target types.

The new model builds on Chai-2 which was released back in 2025 and was described as the first zero-shot antibody design platform to achieve double-digit experimental hit rates and design molecules with drug-like properties, a 100-fold improvement over prior computational approaches.¹ Chai-2 enabled discovery processes to be completed in weeks that previously required months.

The Chai-2 model also demonstrates an antibody design hit rate close to 20%, and prompted with just the target and epitope, Chai-2 also successfully designs all complementarity-determining regions (CDRs) entirely from scratch, a breakthrough in a field where traditional techniques, including those based on AI, consistently show hit rates below 0.1%.²

“I’ve been impressed by the scale of Chai Discovery’s ambition since our early conversations a while ago, when such progress scarcely seemed possible, and it’s incredible to see this breakthrough come so quickly,” said Mikael Dolsten, who served as chief scientific officer of Pfizer for over 15 years. “Chai-2 holds high potential for de novo design of medicines with short turnaround times.”

What are the details of the agreement?

Under terms of the agreement, Pfizer is set to gain early access to Chai-3, Chai's previously undisclosed next-generation model, as well as a custom model built on Pfizer's proprietary data and tailored to its internal workflows.¹ As of June 5, the financial terms of the deal have not yet been disclosed.

Why is this deal significant?

Pfizer's adoption of a custom model trained on its own proprietary data is particularly notable, as it reflects a deeper level of AI integration than standard platform licensing, effectively embedding Chai's capabilities directly into Pfizer's existing scientific infrastructure.¹

"Our work with Pfizer is about putting Chai's software directly into the hands of one of the world's leading drug discovery organizations," Meier said. For Chai, the partnership represents a significant commercial validation of its platform at a moment when competition among AI drug discovery companies for top-tier pharmaceutical partnerships is intensifying across the industry.

Sources

1. Chai Discovery Announces License Agreement with Pfizer to Accelerate Drug Discovery with AI Chai Discovery June 4, 2026 https://www.businesswire.com/news/home/20260602498831/en/Chai-Discovery-Announces-License-Agreement-with-Pfizer-to-Accelerate-Drug-Discovery-with-AI
2. Chai Discovery Unveils Chai-2 Breakthrough, Achieving Fully De Novo Antibody Design With AI Chai Discovery June 30, 2025 https://www.businesswire.com/news/home/20250630307418/en/Chai-Discovery-Unveils-Chai-2-Breakthrough-Achieving-Fully-De-Novo-Antibody-Design-With-AI