Data from Phase 3 COUGH-1 and COUGH-2 Trials Presented at the Virtual European Respiratory Society (ERS) International Congress 2020
Merck (NYSE:MRK), known as MSD outside the United States and Canada, has announced the results from two pivotal Phase 3 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 potential treatment of refractory or unexplained chronic cough. COUGH-1 and COUGH-2 are the first companion Phase 3 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 3 study.
"It is estimated that between 5 and 10% of adults globally suffer from chronic cough. A subset of these patients have refractory or unexplained chronic cough and appear more sensitive to various triggers that do not typically cause cough in healthy subjects. These include everyday things such as talking, laughing, a change in air temperature or exposure to aerosols or food odors, and to date treatment options are extremely limited for these patients," said Dr. Lorcan McGarvey, Clinical Professor, Wellcome-Wolfson Institute of Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast. "Given the significant unmet need for these patients, we are strongly encouraged by the findings of COUGH-1 and COUGH-2 and the potential for a new therapeutic option for patients who are struggling with the burden of this disease, often for many years without relief."
"COUGH-1 and COUGH-2 are the first companion Phase 3 trials in refractory or unexplained chronic cough, underscoring Merck's commitment to fully researching the potential for gefapixant in this patient population," said Dr. Roy Baynes, senior vice president and head of global clinical development, chief medical officer, Merck Research Laboratories. "Both trials met the primary endpoint at the 45 mg twice daily dosage, significantly reducing cough frequency in these patients, and we are grateful for the opportunity to share these data with the scientific community."
These results were presented at the virtual European Respiratory Society (ERS) International Congress 2020 (abstract #3800). Merck plans to share data from COUGH-1 and COUGH-2 with regulatory authorities worldwide.