REUTERS/Brendan McDermid/File Photo Acquire Licensing RightsNov 15 (Reuters) - The U.S. health regulator's staff on Wednesday flagged concerns that data on Merck's (MRK.N) chronic cough drug might not be enough to prove the treatment's meaningful benefit, documents released ahead of a meeting of independent experts showed. The concerns were raised after the company had submitted additional efficacy data to the U.S. Food and Drug Administration (FDA), which declined to approve the drug in January last year. A panel of expert advisers to the FDA is set to meet on Friday to discuss the efficacy of Merck's drug gefapixant. Staff assessment of the data submitted by Merck showed a small reduction in cough frequency and side effects such as loss of taste in patients who were administered the drug. The European Union and Japan have approved Merck's drug for the condition and it is sold under the brand name Lyfnua.

---

Persons: Brendan McDermid, Mara Goldstein, Christy Santhosh, Shinjini Ganguli, Anil D'Silva, Shailesh, Shounak Organizations: Merck, Co, REUTERS, U.S . Food, Drug Administration, FDA, Staff, European Union, Thomson Locations: Rahway , New Jersey, U.S, United States, Japan, Bengaluru