Merck's gefapixant at 45mg hits main goal of Phase III trials for chronic cough

Shares of US pharma giant Merck & Co (NYSE: MRK) were up 1% premarket on Tuesday, after it has released top-line efficacy results from two ongoing pivotal Phase II trials (COUGH-1 and COUGH-2) evaluating the efficacy and safety of gefapixant (MK-7264), an investigational, orally administered, selective P2X3 receptor antagonist, for the treatment of refractory or unexplained chronic cough.

In these studies, the primary efficacy endpoints were met for the gefapixant 45mg twice daily treatment arms – demonstrating a statistically-significant decrease in 24-hour coughs per hour (average hourly cough frequency based on 24-hour sound recordings) versus placebo at 12 (COUGH-1) and 24 weeks (COUGH-2).

Misses at 15mg dose