(CNN) Advisers to the US Food and Drug Administration voted 13-10 Tuesday to recommend emergency use authorization of a pill made by Merck and Ridgeback Biotherapeutics to help treat Covid-19.
Members of the FDA's Antimicrobial Drugs Advisory Committee were split in their vote to recommend molnupiravir, which can reduce the relative risk someone will progress to severe disease or death by about 30%. The absolute reduction in risk of severe disease or death was 3% -- 9.7% of people who took placebo died, compared to 6.8% of those given molnupiravir.
If authorization is granted, the drug would be the first oral antiviral treatment to fight Covid-19. It comes in capsule form.
The pills must be taken within five days of the start of symptoms to do much good, and people must take four pills twice a day for five days. Members of the committee were worried about risks to pregnant women.
"I vote no. Based on the currently available data I think I just need more efficacy and safety data, perhaps by with more subjects against placebo or other treatment strategies, before I can vote yes," said Jennifer Le, professor of clinical pharmacy at the University of California, San Diego.
"I don't think I would want to take this drug, not knowing the effects it would have on my unborn child," said Roblena Walker, the consumer representative on the committee and CEO of Mableton, Georgia, based public health mentoring group EMAGAHA Inc.
"I voted yes because Covid-19 is still an emergency situation. As a frontline clinician in treating patients, both inpatient and outpatient, there is a need for something like this," said Dr. W. David Hardy of the Charles Drew University School of Medicine and Science in Los Angeles. "Although I do have questions about its overall, longer term efficacy, it did meet its pre-specified statistical boundaries of showing a 48% improvement in terms of hospitalization and death."
Most members said they hoped Merck would be asked to continue gathering safety data on the pill.
"I see this as an incredibly difficult decision and as already been stated, there are many, many more questions than answers," said Dr. Lindsey Baden, director of clinical research division of infectious diseases at Brigham and Women's Hospital in Boston, who voted yes.
"Overall, I trust our practitioners that if we educate them properly, they can deploy this properly," Baden added.
Members of the committee noted that while initial data indicated the drug was 50% effective in reducing the risk of severe disease and death, later analysis showed it was just 30% effective.
"The final dataset still represented a 30% reduction in hospitalization and death with a separate significant reduction in deaths that motivated me towards the yes vote," said Dr. George Siberry, medical officer at the US Agency for International Development, who voted yes.
Siberry said he thinks the drug should only be prescribed for adults and women who are pregnant or may become pregnant should be counseled about potential risks. But Siberry said he did not think pregnant women who are at high risk should be excluded from using the drug.
Molnupiravir is not the only antiviral being developed against Covid-19. Pfizer applied for authorization of its antiviral pill this month. The FDA has not yet set a date for its advisory panel to review that drug.
Currently, the only approved antiviral to fight Covid-19 is remdesivir, sold under the brand name Veklury. It's infused and must be given under medical attention. Pills could be prescribed and taken at home.
Other Covid-19 treatments include monoclonal antibodies, which also are infused or injected and kickstart the immune response to infection, steroids to tamp down an immune overreaction to infection in severe disease, and anti-clotting drugs to prevent blood clots.
Molnupiravir interferes with the virus' ability to replicate inside the body. Merck said it's also being studied for its potential to prevent disease in people exposed to the virus.
The company said there's no reason to think the drug will not work against new variants, including the Omicron variant.
"So we have every expectation that, based on the mechanism of action of molnupiravir, that it should work against this particular variant," Dr. Nicholas Kartsonis, Merck's senior vice president for clinical research of infectious diseases and vaccines, told the committee.
"We haven't tested it yet. As you can imagine, we're feverishly working to collect samples, and that it does take a little longer to do this testing for us as opposed to ... a monoclonal antibody because we have to actually evaluate it across the entire genome, we need to collect the virus and evaluate it thoroughly. But we are committed to get those results out as soon as they're available."
The FDA will now consider the committee's recommendation. It doesn't have to follow the committee's advice, but often does.
The US federal government has contracted to buy 3.1 million courses of molnupiravir for $2.2 billion, which works out to about $700 per course of treatment.
"In anticipation of the results from (clinical trials) and the potential for regulatory authorization or approval, Merck has been producing molnupiravir at risk and expects to produce 10 million courses of treatment by the end of 2021, with at least 20 million courses to be produced in 2022," the company said in a statement.
"With the continued spread of the virus and the emergence of variants, additional treatments for COVID-19 are urgently needed. That is why we are moving with speed and rigor to pursue authorizations and to accelerate broad global access to this investigational medicine," added Dr. Dean Li, executive vice president and president at Merck Research Laboratories.
"We are grateful to the members of the Advisory Committee who reviewed our application, as well as to the patients and investigators who participated in our clinical trials, and we will continue to work with the FDA as the agency completes its review."