The FDA could authorize the first COVID-19 pill in December - here's who may be eligible

• The FDA will meet to discuss Merck's COVID-19 pill in late November, which means the treatment could get authorized in December.
• The drug seems to prevent vulnerable people from requiring hospitalization or dying.

The first-ever COVID-19 pill could be available before the end of the year.

This week, Merck and Ridgeback Biotherapeutics asked the Food and Drug Administration (FDA) to authorize their antiviral pill for COVID-19. An FDA advisory panel will meet to discuss the request on November 30 - the first time such a panel has evaluated a COVID-19 treatment. (It did not hold meetings about the other COVID-19 treatments authorized so far.)

If the pill meets the FDA's standards for safety and efficacy, the agency will likely greenlight the drug in December.

Merck's pill was found to halve the risk of hospitalization or death among adults with mild to moderate symptoms. Just 7% of people who received the pill in a clinical trial were hospitalized or died, compared with 14% of those who got a placebo. Each of those groups contained nearly 400 people.

The drug could fill a major hole for doctors looking to treat sick, unvaccinated patients - particularly as the winter threatens to drive up cases.

"If you can stop the virus before it makes someone very sick, then it's a game-changer," Dr. Mike Ryan, executive director of the World Health Organization's Health Emergencies Program, said during a Facebook Q&A earlier this month.

Antiviral pills, Ryan added, are the "holy grail" of treatments.

Here's what to know about Merck's pill.

Who will be eligible?

Merck's pill, molnupiravir, probably won't be available to everyone who gets COVID-19.

To participate in the company's trial, adults had to have at least one factor that put them at risk of severe COVID-19, such as obesity, diabetes, heart disease, or being over age 60. Participants also started the treatment within five days of developing symptoms, so those who have been sick for longer than that may not be eligible.

Merck's trial also looked exclusively at unvaccinated people, so it's not yet known whether the treatment will be recommended for those who get breakthrough cases after getting vaccinated.

Why is a COVID-19 pill necessary?

So far, the FDA has fully approved just one treatment for COVID-19: the antiviral remdesivir, which is administered via injection. That drug has been found to shorten recovery time for hospitalized patients, but it's not a treatment for mild or moderate COVID-19.

The FDA also authorized the emergency use of monoclonal antibodies, drugs that help keep people with mild or moderate symptoms from developing severe COVID-19. These come in two forms, infusions or injections - both of which are administered at hospitals or clinics. Though monoclonal antibodies are free to the public, they can cost the government more than $2,000 per dose.

So drugmakers have been working to develop cheaper, less invasive treatments.

Merck's fits the bill: The drug would cost the government around $700 per treatment (though it would also be free to Americans). That full regimen consists of 40 pills - four capsules twice a day for five days. The drug will likely be available as a prescription at pharmacies.

But it's not a replacement for vaccines, which still offer the highest chance of avoiding hospitalization or death.

Will the pill be easy to get?

The US government has purchased enough of Merck's pill to treat 1.7 million people, and the company already started manufacturing the drug. Merck hopes to produce 10 million treatment courses by the end of the year, much of which would go to other countries.

Merck has signed licensing deals with Indian manufacturers to help deliver the drug to most low- and middle-income countries, assuming the pill gets authorized in those places. The company plans to vary the price of the treatment by country.

How does the pill work inside the body?

Merck's pill belongs to a class of antiviral drugs called nucleosides, which can block a virus from replicating inside cells. This particular drug creates mutations in the part of its genetic code that the virus uses to replicate. Once enough of its code is changed, the virus dies out, preventing a patient's symptoms from getting worse.

"The virus essentially mutates itself to death," Richard Plemper, a virologist at Georgia State University, recently told Nature.

Are there any side effects?

People in Merck's trial reported a similar number of side effects regardless of whether they got the real drug or a placebo (40% of placebo recipients had side effects, compared with 35% of those who got the pill).

"We're very comfortable that the drug will be safe if used as intended," Daria Hazuda, Merck's vice president of infectious diseases discovery, said in a press call earlier this month.

This story has been updated with new information. It was originally published October 12.