A Food and Drug Administration advisory panel voted Tuesday to recommend Merck’s experimental antiviral pill to treat Covid-19 for emergency use authorization, paving the way for the agency to clear the first oral drug for the disease.
Members of the agency’s Antimicrobial Drugs Advisory Committee voted 13-10 in favor of the treatment, called molnupiravir, for use in adults with mild to moderate Covid-19 who are at risk for severe disease or hospitalization.
During the daylong public meeting, committee members raised numerous questions and expressed concerns about the safety and efficacy of the drug, which is made by Merck and Ridgeback Biotherapeutics, before narrowly voting in favor.
Many members of the advisory committee described the vote as a difficult one, in which they had to carefully weight the risks and benefits of a drug that could help those most at risk but raised many unanswered questions. Several committee members recommended that Merck’s emergency use authorization be revisited and potentially withdrawn if another treatment becomes available later.
Merck originally said the drug was more than 50% effective in preventing hospitalizations and death, but a more full set of data presented to the FDA on Tuesday noted the drug is just 30% effective.
The FDA and Merck both recommended against using the drug in kids and pregnant women. Molnupiravir was found to be lethal to embryos in pregnant rats, also causing birth defects and reducing fetal body weight. It also caused other defects that interfered with bone growth in young pups, along with other abnormalities, the data shows.
Molnupiravir works by prompting the virus that causes Covid to mutate and produce errors inhibiting its ability to replicate and spread. However, some doctors and scientists worried that it could also enable the virus to mutate in a way that makes vaccines and treatments less effective.
“Even if the probability is very low, 1 in 10,000 or 100,000, that this drug would induce an escape mutant from which the vaccines we have do not cover, that could be catastrophic for the whole world actually,” Dr. James Hildreth, CEO of Meharry Medical College told the panel.
Hildreth was one of the 10 committee members who voted not to recommend emergency authorization of molnupiravir..
He later expressed concerns in a post on Twitter.
“FDA AMDAC has voted 13 yes, 10 no for EUA for Merck’s molnupiravir COVID-19 drug. I voted no. Inclusive data on mutagenic potential and concerns over generating troublesome SARS-CoV2 variants were not addressed to my satisfaction. Drug has modest 30% reduction in COVID-19 risk,” Hildreth said in the post.