Shares of vaccine makers Moderna (MRNA) - Get Moderna, Inc. Report, Novavax (NVAX) - Get Novavax, Inc. Report and Pfizer's (PFE) - Get Pfizer Inc. Report German biotech partner BioNTech (BNTX) - Get BioNTech SE Sponsored ADR Report fell after Merck (MRK) - Get Merck & Co., Inc. (MRK) Report said it would seek emergency-use approval from the Food and Drug Administration for a Covid pill.
The Kenilworth, N.J., health-care giant said its experimental Covid-19 pill cut the risk of hospitalization and death in high-risk patients by as much as 50%.
The results were from an interim analysis of a late-stage clinical trial, Merck and partner Ridgeback Biotherapeutics said in a statement on Friday.
The drug, known as molnupiravir, would offer an at-home treatment option for Covid patients.
At last check shares of Moderna and Novavax fell 9.7% and 17% respectively. U.S.-listed shares of BioNTech dropped 7.7%.
Bloomberg reported that results of Merck's clinical trial were so encouraging that closely held Ridgeback, the rare-drug specialist, in consultation with independent trial monitors and the FDA, elected to stop enrolling patients and begin the process of gaining regulatory clearance.
Anthony Fauci, the immunologist who heads the National Institute of Allergy and Infectious Diseases, called the data impressive and indicated that regulators would move fast to review it once the application is submitted.
At a White House Coronavirus Task Force briefing on Friday, Fauci hesitated to give a timeline for emergency-use authorization.
Meanwhile, Moderna is awaiting a specific booster shot approval from the FDA and the Centers for Disease Control and Prevention.