- Several oral antiviral treatments for COVID-19 are currently being studied.
- Merck will ask for emergency use authorization for its daily pill after a clinical trial showed its drug molnupiravir reduced the risk of hospitalization or death from COVID-19 by 50 percent.
- Proponents say the pills would provide people with an easy and accessible way to treat symptoms of COVID-19.
- Others, however, say developing antiviral treatments for other illnesses such as the flu have proven to be more difficult than first anticipated.
For some, treatment for COVID-19 could be as simple as taking a daily pill.
Several oral antiviral treatments for COVID-19 are in the works, including one that may be available soon.
Merck and Ridgeback Biotherapeutics officials plan to seek emergency use authorization (EUA) from the Food and Drug Administration for their medication known as molnupiravir after what they described as a successful phase 3 clinical trial.
Company officials said today that molnupiravir reduced the risk of hospitalization or death from COVID-19 by 50 percent for trial participants with mild to moderate symptoms who took the medication compared with participants who were given a placebo.
“With these compelling results, we are optimistic that molnupiravir can become an important medicine as part of the global effort to fight the pandemic,” said Robert M. Davis, CEO and president of Merck, in a statement.
Dr. Monica Gandhi, MPH, a professor of medicine at the University of California San Francisco, explained the clinical trial results and their importance.
“Molnupiravir is an antiviral (nucleoside analog) originally designed to be a broad spectrum against many viruses by inhibiting viral replication,” she told Healthline. “In the test tube, molnupiravir inhibits replication of SARS-CoV-2, the agent that causes COVID-19, so it was tested first in a phase II trial that showed the time to viral RNA clearance decreased and a greater proportion of participants (92 percent) overall achieved viral clearance in those who received 800 mg molnupiravir twice daily.”
“Molnupiravir was then tested in a phase 3 trial of outpatients with mild to moderate COVID-19 who had at least one risk factor for developing severe disease to see if the drug worked to prevent hospitalization or death and the interim analysis of the trial (775 participants out of 1,500 enrolled) were released today,” she added. “The interim analysis of the trial (called MOVe-OUT) showed that molnupiravir reduced the risk of hospitalization or death by 50 percent (7 percent of those on molnupiravir either hospitalized or died through Day 29 (28/385), compared with 14 percent of placebo-treated patients (53/377). Through Day 29, no deaths were reported in patients who received molnupiravir, as compared to 8 deaths in patients who received placebo.”
“This is a very exciting finding for the first outpatient antiviral to be likely to be approved for the treatment of mild-moderate COVID-19 and the company announces it will file for EUA, with the government already approving the purchase of 1.7 million doses based on this positive finding,” Gandhi concluded.
Pfizer and Roche are also conducting late-stage clinical trials on antiviral drugs that could treat people in the early stages of COVID-19.
If given emergency approval, these treatments could become available by early next year.
Experts say antiviral treatments represent an important front in curtailing and ending the COVID-19 pandemic and its transition to an endemic disease that’s among the population but manageable.
Antiviral drugs — already used to treat HIV, hepatitis C, and the flu, among others — work by inhibiting viral replication, lowering viral loads, and making people less sick as well as potentially less likely to transmit the virus to others, experts say.
One antiviral drug, remdesivir, has been used as a COVID-19 treatment, but it’s intended for hospitalized patients with advanced cases of the disease, whereas the new antivirals could be dispensed at a pharmacy without physician intervention.
“These drugs have the potential to play a significant role in navigating the COVID-19 pandemic,” said Dr. Kelly McKee Jr., MPH, the chief scientific officer consultant on the clinical team for Revive Therapeutics’ FDA phase 3 trial for Bucillamine, an antirheumatic agent being tested as an oral COVID-19 treatment.
“A ‘COVID-19 pill’ would aim to inhibit replication of the virus to the point that the body’s natural defenses can effectively combat it, reducing the severity of the infection and preventing (or at least lessening the likelihood) of progression to severe disease, hospitalization, or worse,” McKee told Healthline.
“In addition, depending upon the safety profiles of one or more of these drugs, it may be possible to prevent infections from even developing in individuals who are at high risk for becoming infected,” he said.
He called the development of such drugs “an important measure that complements vaccination and nonmedical interventions (e.g., masks, physical distancing, frequent handwashing) to reduce the spread of infection in communities.”
Not everyone thinks these antiviral treatments will be game changers.
“Creating new antivirals in the time of a COVID-19 pandemic is not as easy as it looks,” said Ravi Starzl, PhD, an adjunct professor at Carnegie Mellon University in Pittsburgh and cofounder and CEO of biotech companies BioPlx and Firebreak Inc.
“Specifically, with the flu, the attempt to create antivirals to treat the flu or influenza proved to be extremely difficult, as viruses are efficient little engines of destruction,” Starzl told Healthline.
He noted that clinically approved antiviral drugs are currently available for only 10 of the more than 220 viruses known to infect humans. They also can have considerable side effects that can limit their overall usefulness.
Kristen Nichols, PharmD, a senior content management consultant in pediatric infectious diseases at information services company Wolters Kluwer, agreed.
“There isn’t a strong history of finding good antivirals that really change the course of upper respiratory tract infections in otherwise healthy people,” she told Healthline. “Even Tamiflu’s efficacy isn’t always clear. Generally, the best efficacy is seen if the drug can be started early in the infection before the virus has had a lot of opportunity to replicate.”
Still, early intervention is where manufacturers are hoping to target these COVID-19 treatments.
And that’s easier to accomplish with a pill rather than an injection.
“It would be great if such a drug would be shown to decrease transmission of COVID and decrease risk of hospitalization, as that could hopefully decrease the pressure/overcrowding that hospitals are currently facing,” Nichols said. “It could also have an impact in potentially getting people with mild to moderate illness back in the workforce more quickly.”
But, she cautioned, “we really need to see peer-reviewed results of studies for these drugs before drawing any conclusions. Right now, we are operating on press releases from manufacturers, which are clearly at high risk of bias.”