Merck (MRK) and Ridgeback Biotherapeutics said Friday that a recent analysis of data from a large clinical trial showed their COVID-19 pill molnupiravir was less effective in preventing death or hospitalization than previously reported.
The companies said the most recent analysis showed the antiviral medication was able to reduce the relative risk of death or hospitalization from COVID-19 by 30%. An earlier analysis showed the drug help cut the risk by 48%.
The updated analysis showed molnupiravir lowered the risk of hospitalization or death to 6.8%, compared with 9.7% for the placebo group. Nine deaths were reported out of the 699 people enrolled in the placebo group, while one person died out of the 709 given molnupiravir.
Merck and Ridgeback have been developing molnupiravir for the treatment of mild to moderate COVID-19 in adults at risk for developing severe cases of the disease. The drug is currently under review by the US Food and Drug Administration for an emergency use authorization. The companies said the most recent analysis will be presented to the FDA's Antimicrobial Drugs Advisory Committee on Nov. 30.
Molnupiravir has already been authorized by UK regulators and is currently being reviewed by the European Medicines Agency, the companies added.
Pfizer (PFE) has been seeking authorization for its COVID-19 pill Paxlovid, also known as ritonavir, which was shown to cut the risk of death or hospitalization by 89% in infected patients at risk for developing severe complications from the disease.
Pfizer submitted an application with the FDA for emergency use authorization on Nov. 16. The company is also seeking authorization from the EMA and has begun the rolling submission process with regulators in the UK, Australia, New Zealand, and South Korea.
On Nov. 18, Pfizer said that it has agreed to supply the US government with 10 million courses of Paxlovid, pending FDA authorization.