What Is the Covid-19 Pill and When Will It Be Ready?
A new Covid-19 treatment pill, called molnupiravir, is in the works to help treat mild cases of coronavirus. Here's what the science says about this drug, which has been likened to Tamiflu.
A potential Covid-19 pill
In all of the excitement about Covid-19 vaccines, the world has almost forgotten about Covid-19 treatments. But researchers remember, and they’ve been working to find medications that treat the virus.
Most Covid-19 treatments are still in the early phases of clinical trials, but scientists recently shared positive results for a pill called molnupiravir, which could treat mild cases of Covid-19.
Many are likening the therapy to the influenza treatment Tamiflu.
“I think it could be very significant if it has really important clinical outcomes, [like] a reduction in risk of more severe illness or people are symptomatic for a shorter period of time,” says David Herschwerker, MD, an attending physician in infectious diseases at Northwell Health in Manhasset, New York. “Tamiflu generally reduces the duration of symptoms, and that could be really important, particularly for the most vulnerable populations.”
Right now, there’s no evidence of molnupiravir’s benefits, but experts are hoping research findings may be available by the end of the year.
What exactly is molnupiravir?
Molnupiravir is an antiviral drug developed by Merck and Ridgeback Therapeutics. Like other antivirals, molnupiravir interferes with the ability of SARS-CoV-2, the virus that causes Covid-19, to replicate. If the virus doesn’t replicate, it doesn’t cause symptoms and it can’t spread.
On March 6, the codevelopers announced results of a Phase 2a trial showing that molnupiravir was safe among 202 people and cut the amount of time participants had detectable levels of virus in their nostrils.
After five days, none of the 47 participants who took molnupiravir tested positive for Covid-19, compared with 24 percent of their peers (six out of 25) who took a placebo. The study involved 202 Covid-19 patients who were not hospitalized.
The study’s findings are a good sign, but they’re only a first step. The goal of Phase 2 trials is to confirm the safety of a drug in a small group of people. Phase 3 trials, which are larger and look more closely at efficacy and safety, are next for molnupiravir.
What science doesn’t know
The recently completed study was small, and the results have not been peer-reviewed, which helps weed out invalid or poor-quality studies.
Importantly, the study did not look at what effect molnupiravir had on the course of the actual disease. That is, researchers don’t know whether it reduces hospitalizations or deaths or if it simply kills the virus.
“Until we have that information, I’m going to be a little skeptical,” says Adarsh Bhimraj, MD, chair for the Infectious Diseases Society of America Covid-19 treatment and management guidelines.. “We have seen a lot of things that kill the virus but don’t translate into meaningful outcomes for the patients.”
The Phase 3 trial will provide more of the information we need: Is there a benefit in terms of symptoms or severity of illness? (Here’s the difference in Covid-19 symptoms vs. flu symptoms.)
With vaccines, why do we still need Covid-19 treatments?
Even with three vaccines approved in the United States, and at least one more on the way, we will be living with the virus for quite some time. Why? The vaccines aren’t perfect (although they are very, very good), they could be outwitted by new variants, and not everyone is getting vaccinated.
“I believe there will be a lot less illness in communities by summer, but I don’t anticipate that Covid-19 will go away for several years,” says Dr. Herschwerker. (Here’s what to know about the Covid-19 vaccines: Moderna vs. Pfizer.)
It’s important to remember that ending the pandemic does not eliminate Covid-19.
“It means reducing the number of infections to very low levels,” says William Schaffner, MD, an infectious diseases specialist with Vanderbilt University Medical Center in Nashville.
People who get sick will still need to be treated.
A vaccine pill?
What’s better than a vaccine shot? Potentially a vaccine pill. The company Oravax plans to start a clinical trial on such a candidate in the second quarter of 2021.
The company’s pill showed good results after just one dose in animals and might cover mutations. Needless to say, a vaccine pill would be easier to take and easier to give than a shot but there’s still a distance between preclinical animal studies and human studies that prove effectiveness and safety.
Current Covid-19 treatments
Most of the therapies available right now for Covid-19 are for severely ill, usually hospitalized, patients.
The Food and Drug Administration has approved only one antiviral drug, called remdesivir.
“The benefit is not dramatic,” says Dr. Herschwerker. “It reduces the number of days of illness, but there’s no impact on mortality.”
Antibodies collected from patients who have survived the virus—known as convalescent plasma therapy—have shown promise but they have to be given intravenously, either in a hospital or special clinic.
The steroid dexamethasone does save lives but it too is usually only administered in hospitals.
The bottom line: “Mostly we have had some modest benefits for severely ill patients,” says Dr. Bhimraj.
The potential impact of a Covid-19 pill
Not only will we continue to need new treatments, but we especially need help for people with mild cases of the illness, many of whom are younger.
A pill that is not expensive and can be given to patients with mild disease early would be a boon.
“Although most in this group of patients would get better on their own, if one of them gives Covid-19 to Grandma with heart problems, she could die,” says Dr. Bhimraj, who is also section head of neurologic infectious diseases at the Cleveland Clinic.
Other Covid-19 drugs in the pipeline
Like molnupiravir, other drugs are in various stages of development. None have robust Phase 3 results. Some drugs to watch:
- PF-07321332: From Pfizer, this would also provide treatment in the early phases of the disease. It’s a type of antiviral drug known as a protease inhibitor which would be given in pill form twice a day for five days. Safety results are expected within weeks and trials to assess efficacy would start after.
- Upamostat: The antiviral is being studied in people with early Covid-19.
- Opaginib (Yeliva): This antiviral and anti-inflammatory drug is under development as a possible treatment for Covid-19. It may reduce the need for oxygen in certain patients when added to remdesivir or dexamethasone.
- Favipiravir: Another oral antiviral, this is approved in Japan for influenza. Meanwhile, the same drug, under the brand name Avifavir, is approved in Russia for Covid-19. Much like in the molnupiravir study, a Russian trial found that more people taking Avifavir tested negative for SARS-CoV-2 than those taking a placebo. Researchers are also investigating whether favipiravir can prevent Covid-19.
There’s some concern that drugs currently in development may not be useful against Covid-19 variants. “There’s going to be a need to do testing of the therapeutics against the variants,” says Dr. Herschwerker.
Keep practicing Covid-19 prevention
The United States is still logging Covid-19 cases at the rate of 50,000 to 60,000 a day, Dr. Herschwerker points out. So while news of a Covid-19 pill is promising, it’s not a sign the pandemic is over.
And though vaccines may be the key to the end of the actual pandemic, they’re not likely to eliminate Covid-19 completely. Current treatments “are much better than they were a year ago, but they’re not perfect,” says Dr. Schaffner. Meanwhile, new medications are on the horizon but they’re not here yet.
The most important thing now is to get vaccinated and to keep up with prevention efforts. That means wearing a mask, keeping your distance from others, not gathering in large groups, and washing your hands frequently with soap and water.
Next, learn about double masking and other ways to prevent Covid-19.
- David Hirschwerk, MD, attending physician, infectious diseases, Northwell Health, Manhasset, New York
- Medscape: "First Pill for COVID-19 Could Be Ready by Year's End"
- Merck: "Ridgeback Biotherapeutics and Merck Announce Preliminary Findings from a Phase 2a Trial of Investigational COVID-19 Therapeutic Molnupiravir"
- Food and Drug Administration: "Step 3: Clinical Research"
- Adarsh Bhimraj, MD, chair, Infectious Diseases Society of America Covid-19 treatment and management guidelines and section head of neurologic infectious diseases, Cleveland Clinic
- William Schaffner, MD, infectious diseases specialist, Vanderbilt University Medical Center, Nashville
- Nature: "Coronavirus breakthrough: dexamethasone is first drug shown to save lives"
- Medscape: "What is the role of molnupiravir and favipiravir in the treatment of coronavirus disease 2019 (COVID-19)?"
- University Hospitals: "COVID-19 Drug Study for Out-Patient Care"