Merck has entered into a $1.25 billion deal to acquire California-based Afferent Pharmaceuticals, which is developing a treatment for chronic cough, writes John George for the Philadelphia Business Journal.

Merck, which has a large research and manufacturing plant in Upper Gwynedd, anticipates the transaction will close in the third quarter of this year.

Under the terms of the deal, Merck will make an upfront payment of $500 million, and Afferent’s shareholders will also be eligible to receive an additional $750 million tied to clinical development and commercial milestones on its drug candidates, including AF-219.

AF-219 is an orally-administered, non-narcotic drug in mid-stage testing as a potential treatment for chronic cough. Chronic cough usually lasts longer than eight weeks and affects close to 10 percent of adults in the country.

Dr. Roger M. Perlmutter, President of Merck Research Laboratories, said that Afferent has also pioneered clinical development of new investigational candidates which selectively target the P2X3 receptor. P2X3 receptors are thought to play a crucial role in the sensitization of certain sensory nerves.

“It’s an exciting area of research,” said Perlmutter.

Read more about the deal in the Philadelphia Business Journal by clicking here.