Heptares Therapeutics, a subsidiary of the Sosei Group, has entered into a strategic drug discovery collaboration with Pfizer to research and develop potential new medicines directed at up to 10 G protein-coupled receptor (GPCR) targets across multiple therapeutic areas.

Heptares will use its proprietary GPCR structure-guided platform to help deliver stabilized GPCRs (StaR proteins), high-resolution crystal structures and other technologies to support the discovery of potential novel agents directed to the GPCR targets selected by Pfizer. Pfizer will be responsible for developing and commercializing any potential therapeutic agents (small molecules or biologics derived from StaR antigens) for each target and will have exclusive global rights to any potential resulting agents.

Heptares will receive an initial payment on signing the agreement in return for delivering certain StaR proteins and structures for targets selected by Pfizer that it already has generated.

Heptares is eligible to receive potential research, development, regulatory and commercial milestone payments of up to $189 million per target. In addition, Heptares is eligible to receive potential tiered royalties on the net sales of any products that are commercialized by Pfizer.

Sosei and Pfizer Seiyaku have entered into an equity agreement under which Pfizer will purchase $33 million of newly issued Sosei common stock at a premium of 25% to the average closing price during the 20-day period prior to the closing date. The closing is expected to be in December. The investment will represent 3.02% of the enlarged Sosei share capital and is subject to review by Japanese financial authorities.