FDA panel flags insufficient data for Merck's chronic cough drug

FILE PHOTO: The Merck logo is seen at a gate to the Merck & Co campus in Rahway, New Jersey, New Jersey

By Khushi Mandowara and Christy Santhosh

(Reuters) -Advisers to the U.S. health regulator said on Friday that data on Merck's chronic cough drug does not provide sufficient evidence to prove its clinical benefit for patients.

The U.S. Food and Drug Administration's (FDA) panel voted 12 to 1 against the late-stage data submitted by Merck for the drug gefapixant, which showed a small reduction in cough frequency compared to a placebo.

Patients who received the treatment also experienced side effects such as loss of taste.

While the FDA advisers said side effects from use of the drug were manageable, they questioned the effectiveness of the drug citing a high number of patients who dropped out of the study.

Late-stage data from Merck showed 22% patients treated with high dose of the drug discontinued the treatment due to adverse events.

"If they were feeling so much benefit would they have dropped out ... if that's how many (patients) are dropping out in trial, I would expect to see a bigger drop out rate in the real world," FDA adviser Emma D'Agostino, a consultant at Cystic Fibrosis Foundation, said.

The panel's vote could further delay the regulatory path for Merck's drug, which the FDA has already declined to approve once last year.

Merck said it disagreed with the committee as the data showed a meaningful clinical benefit for adults with refractory or unexplained chronic cough.

FDA, which generally follows the advise of its panel, but is not bound to do so, will make a decision on the drug by Dec. 27.

If approved, Merck's drug is up against GSK-owned camlipixant, which is in late-stage development for the treatment of chronic cough with anticipated regulatory approval and launch in 2026.

Currently, there are no FDA-approved therapies for chronic cough, which Merck said affects about 5% to 10% of the global adult population.

(Reporting by Christy Santhosh and Khushi Mandowara in Bengaluru; Editing by Shounak Dasgupta)