Merck (NYSE:MRK) has received another setback as the U.S. Food and Drug Administration (FDA) issued a complete response letter (CRL) for its new drug application (NDA) seeking approval for the oral P2X3 receptor antagonist, gefapixant. The drug was intended for the treatment of refractory chronic cough (RCC) or unexplained chronic cough (UCC) in adults.
The FDA, in the CRL, stated that the data presented by Merck did not provide sufficient evidence to establish the clinical benefit of gefapixant in treating RCC and UCC. Importantly, the FDA did not express any safety concerns regarding the use of gefapixant. Merck is currently reviewing the FDA’s feedback to determine the appropriate course of action.
This recent FDA decision aligns with the negative recommendation from an FDA advisory committee last month, where members voted 12-to-1, expressing skepticism about the drug’s clinical meaningfulness for adults with RCC and UCC. Notably, this marks the second time that the FDA has declined approval for gefapixant, having issued a CRL last year, requesting additional information on the drug’s efficacy measurement.
While Merck received approval for gefapixant in the European Union under the trade name Lyfnua, and in Japan in January 2022, the repeated setbacks in the U.S. market have impacted the company’s shares, which have seen a 5.0% decline year to date compared to the industry’s 5.6% growth.
Chronic cough, lasting longer than eight weeks, is a challenging condition. RCC persists despite the treatment of underlying conditions like asthma or gastroesophageal reflux disease, while UCC remains unexplained despite thorough evaluation. Currently, there are no approved treatments for RCC or UCC in the United States.
This recent development may favor GSK plc (GSK), which is actively developing its own investigational chronic cough drug, camlipixant. GSK acquired camlipixant through the acquisition of Bellus Health in June and is evaluating it in late-stage development as a potential first-line treatment for adult patients with RCC. GSK anticipates launching its RCC drug commercially in 2026.
Featured Image: Megapixl
