Deal worth up to $1.25bn includes drug candidate for chronic coughs

Pharma major Merck & Co has agreed to buy US-based neurology specialist Afferent Pharmaceuticals. Merck will pay $500 million (£354 million) up front, plus up to $750 million in performance-related milestone payments relating to Afferent’s lead drug candidate AF-219 and other molecules in their pipeline.

AF-219 is in Phase II clinical trials for treating chronic coughs as well as coughs associated with idiopathic pulmonary fibrosis. AF-219 blocks P2X3 purine receptors, which lowers the sensitivity of sensory nerves involved in these coughing conditions. Several companies, including Merck, have investigated P2X3 receptor blockers for various conditions – particularly pain management.