Researchers from Montefiore Health System and Albert Einstein College of Medicine, under a recently launched Phase 3 clinical trial, are investigating whether the Merck antiviral pill, molnupiravir, can prevent COVID-19 in unvaccinated individuals living with people who have contracted the disease.
Today, The U.K. approved the drug as a treatment, noting it is “safe and effective.” Molnupiravir is the first oral medication approved for patients with COVID-19. According to data release by Merck, people with mild or moderate cases of COVID-19 who took molnupiravir reduced their risk of hospitalization and death by approximately 50%.
“Based on results of a recent Centers for Disease Control and Prevention study involving the highly transmissible delta variant, we estimate that unvaccinated people living with a person with COVID-19 have a high risk—as great as an 80% to 100% chance—of becoming infected, regardless of their age or preexisting conditions,” said Barry Zingman, M.D., the principal investigator for the Montefiore-Einstein site. “If molnupiravir can prevent these vulnerable close contacts from becoming infected, it will save lives.”
At present, the only drugs used to prevent COVID-19 are monoclonal antibody (mAb) therapies which must be infused into the bloodstream in a clinic or physician’s office. Although molnupiravir has not yet been approved for treating or preventing COVID-19, the new antiviral pills could potentially have a bigger impact than the mAb therapies, by making them more readily available and easier to adminster.
The Montefiore-Einstein molnupiravir collaboration is a randomized, double-blind, placebo-controlled study that will seek to enroll roguhly 1,300 people at 114 sites globally. The Montefiore-Einstein site in New York will enroll 10 to 20 people. All participants must be aged 18 or older, be completely unvaccinated, exhibit no COVID-19 symptoms, and share a household with someone known to have tested positive for COVID-19 within the previous 5 days.
Half of the participants will take four molnupiravir pills twice daily for 5 days, while the other participants will receive the same number of placebo pills over that time. Two- and four-weeks after the start of treatment, Dr. Zingman and colleagues will determine the percentage of participants in the two groups who develop COVID-19. All participants will be counseled on the benefits of COVID-19 vaccination to prevent future infections. The trial is expected to end in April.
Molnupiravir works through deception—its molecules are absorbed by virus-infected cells and converted into defective RNA “building blocks.” Viral enzymes unwittingly use these defective building blocks to construct the genetic material of newly minted viruses, which now can no longer reproduce. Since COVID-19 viral variants and other RNA viruses use the same basic building blocks, a hope is that molnupiravir might work against the virus that causes COVID-19 and possibly other viral infections as well.