KENILWORTH, N.J.--(BUSINESS WIRE)--Merck (NYSE:MRK), known as MSD outside of the United States and Canada, today announced the presentation of results from a Phase 2 study evaluating the safety, efficacy and therapeutic dose range of MK-7264 (formerly AF-219) for the treatment of chronic cough. The highest dose evaluated, 50 mg, reduced Awake Cough Frequency (coughs/hour), the primary endpoint, by 37 percent from baseline relative to placebo (p=0.003). The 50 mg dose also demonstrated a reduction in patient-reported cough severity. Lower doses (7.5 mg and 20 mg) were not statistically significant. The results were presented today at the American Thoracic Society 113^th Annual Conference 2017 in Washington, D.C.

MK-7264 is an orally-administered, non-narcotic, P2X3 receptor antagonist. Merck plans to discuss these results and the Phase 3 clinical development plan for MK-7264 with regulatory agencies later this year.

“There is a significant unmet need for effective treatments for chronic cough,” said Dr. Jacky Smith, professor of respiratory medicine at the University of Manchester and University Hospital Manchester NHS Foundation Trust. “We are encouraged by the results of the MK-7264 study and look forward to further evaluations of this investigational therapy.”

The randomized, double-blind, placebo-controlled, parallel group study evaluated MK-7264 in patients (n=253) with refractory chronic cough (chronic cough for ≥ 1 year; patients were included in the study per ATS/BTS guidelines). Patients were randomized to receive placebo (n=63), 7.5 mg (n=63), 20 mg (n=63), and 50 mg (n=63) doses of MK-7264 twice daily. The primary efficacy endpoint was the mean change in Awake Cough Frequency after 12 weeks of treatment vs. baseline. Cough frequency was measured using sound recordings obtained by a digital recording device. Patients who received a 7.5 mg, 20 mg and 50 mg dose of MK-7264 experienced a reduction in Awake Cough Frequency from baseline compared to placebo of 22 percent, 22 percent and 37 percent respectively; the difference for the 50 mg dose compared to placebo was statistically significant (p<0.05). The secondary endpoint of patient-reported Cough Severity (0-100mm on the Visual Analog Scale) compared to baseline showed a reduction of 15.2mm for placebo, 19.2mm for 7.5 mg, 23.4mm for 20 mg and 31.1mm for 50 mg doses.

Dysgeusia, an alteration in taste, was the most common adverse event reported in 4.8 percent, 9.5 percent, 33.3 percent and 47.6 percent of patients receiving placebo, 7.5 mg, 20 mg, and 50 mg of MK-7264, respectively. Hypogeusia, reduced ability to taste, was reported in 1.6 percent, 0 percent, 17.5 percent and 23.8 percent of patients on placebo, 7.5 mg, 20 mg, and 50 mg of MK-7264, respectively. One patient in the placebo group and six patients in the 50 mg treatment group discontinued due to taste-related adverse events. No patients in the 7.5 mg and 20 mg groups discontinued due to taste-related adverse events.

“These results, from the largest study to date in chronic cough, provide evidence to continue evaluating MK-7264,” said Dr. Andrew M. Tershakovec, executive director, clinical research, Merck Research Laboratories. “We look forward to further discussions with regulatory agencies this year to discuss next steps.”

About MK-7264

MK-7264 (formerly AF-219) is an investigational orally administered non-narcotic therapeutic candidate that selectively blocks the P2X3 receptor. It is believed that excessive activation of P2X3 receptors is associated with hyper-sensitization of sensory neurons. Neuronal hyper-sensitization in the airways and lungs, triggered by injury or infection, can cause an exaggerated, persistent and frequent urge to cough, so called chronic cough.

About Chronic Cough

The prevalence of chronic cough (a cough lasting more than 8 weeks) is estimated at ~10 percent of U.S adults. There are currently no approved therapies for the treatment of chronic cough.

About Merck

For more than a century, Merck, a leading global biopharmaceutical company known as MSD outside of the United States and Canada, has been inventing for life, bringing forward medicines and vaccines for many of the world’s most challenging diseases. Through our prescription medicines, vaccines, biologic therapies and animal health products, we work with customers and operate in more than 140 countries to deliver innovative health solutions. We also demonstrate our commitment to increasing access to health care through far-reaching policies, programs and partnerships. Today, Merck continues to be at the forefront of research to advance the prevention and treatment of diseases that threaten people and communities around the world - including cancer, cardio-metabolic diseases, emerging animal diseases, Alzheimer’s disease and infectious diseases including HIV and Ebola. For more information, visit www.merck.com and connect with us on Twitter, Facebook, Instagram, YouTube and LinkedIn.

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