Phase III COUGH-1 and COUGH-2 trials of MK 7264 shows mixed results in chronic cough.- Merck Inc

Merck Inc announced the results from two pivotal Phase III trials (COUGH-1 and COUGH-2) evaluating the efficacy and safety of MK 7264 (gefapixant), an investigational, orally administered, selective P2X3 receptor antagonist, for the potential treatment of refractory or unexplained chronic cough. COUGH-1 and COUGH-2 are the first companion Phase III trials ever conducted in patients with refractory chronic cough, a cough that persists despite appropriate treatment of underlying conditions, or unexplained chronic cough, a cough where the underlying cause cannot be identified despite a thorough evaluation. In these studies, adult patients treated with gefapixant 45 mg twice daily demonstrated a statistically significant reduction in 24-hour cough frequency (measured objectively, as coughs per hour, using 24-hour sound recordings) versus placebo at 12 weeks (COUGH-1) (18.45% reduction relative to placebo, 95% CI [-32.92, -0.86; p=0.041]) and 24 weeks (COUGH-2) (14.64% reduction relative to placebo, 95% CI [-26.07, -1.43; p=0.031]). The gefapixant 15 mg twice daily treatment arms did not meet the primary efficacy endpoint in either Phase III study. These results were presented at the virtual European Respiratory Society (ERS) International Congress 2020.