Pfizer and UK-based clinical-stage discovery group Heptares have entered into a strategic drug discovery collaboration to research and develop potential new medicines across multiple therapeutic areas based on G protein-coupled receptors.

According to Heptares, the GPCR superfamily is the largest and single most important family of drug targets in the human body, playing a central role in many biological processes and a wide range of diseases. GPCRs transmit signals from outside the cell across the membrane to signalling pathways within the cell, between cells and between organ systems.

There are over 375 GPCRs encoded in the human genome, of which 225 have known ligands and 150 are orphan targets, and the are the site of action of 25-30 percent of current drugs. In fact, the firm notes that six of the top ten and 60 of the top 200 best-selling drugs in the US in 2010 target GPCRs.

Under the deal, Heptares will use its technology to produce StaR proteins - stabilised GPCRs with a small number of point mutations that greatly improve thermostability without disrupting pharmacology - for up to 10 targets selected by Pfizer.

Pfizer will be responsible for developing and commercialising any potential therapeutic agents, either small molecules or biologics derived from StaR antigens, for each target, and will have exclusive global rights to any resulting product.  

Heptares, a wholly-owned subsidiary of Sosei, 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 has already generated, and could also bag up to $189 million per target in research, development, regulatory and commercial milestone payments as well as potential tiered royalties on future sales.

Pfizer’s Rod MacKenzie, who heads the PharmaTherapeutics Research & Developments unit at the firm, said the collaboration will help accelerate screening and identification of lead GPCR programs across multiple therapeutic areas within its preclinical portfolio “and, ultimately, help us increase the speed at which we bring potential new therapies to patients”.