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University of North Carolina at Chapel Hill research set the stage to seek emergency authorization of the first oral antiviral drug to treat COVID-19, a pill developed by the pharmaceutical companies Merck and Ridgeback Biotherapeutics. William Fischer, MD, at the UNC School of Medicine led pivotal clinical trials on the drug molnupiravir.


CHAPEL HILL, NC – Scientists at the University of North Carolina at Chapel Hill say a twice-daily pill – molnupiravir — could change the way COVID-19 is treated. Today’s announcement by Merck Co. to seek emergency authorization by the Food and Drug Administration reflects early research and testing conducted at the UNC-Chapel Hill. 

Strong clinical trial results showed the experimental COVID-19 pill reduced hospitalizations and deaths by half in people recently infected with coronavirus. UNC-Chapel Hill began working on molnupiravir in 2016 and showed the drug could be a weapon against coronaviruses and future pandemics.  

“This is a real game changer for a pandemic like COVID-19 because it allows us to treat people quicker with a method that’s convenient and accessible,” said William A. Fischer II, an associate professor of pulmonology and critical care at the UNC School of Medicine and director of emerging pathogens at the UNC Institute for Global Health and Infectious Diseases. 

Fischer led phase 2 clinical trial with Merck and Ridgeback Biotherapeutics that set the stage for further testing. If approved by the FDA, the pill to treat COVID-19 could be available by the end of the year.  

The UNC-Chapel Hill- led study revealed those who took molnupiravir at their first sign of COVID-19 symptoms had a quicker reduction in coronavirus than those in a placebo group. After five days, tests were unable to detect infectious virus in volunteers who took molnupiravir twice a day.  

Molnupiravir pill

Molnupiravir, which was discovered at Emory University, was originally designed to fight flu, but animal testing at UNC Gillings School of Global Public Health, Vanderbilt University and Emory, showed it blocked transmission of the virus that causes COVID-19 and reduced lung damage. The drug also inhibited coronavirus in recent studies at UNC School of Medicine using human lung cellsUsing a novel in vivo research model, UNC School of Medicine scientists led by Victor Garcia, PhD, and Angela Wahl, PhD, demonstrated that the drug proved dramatically effective at preventing and treating SARS-CoV-2 infection in human tissue in the lab. Their work was published in Nature in early 2021.

Timothy Sheahan, a virologist at UNC Gillings School of Global Public Health and pioneer of antiviral drug research along with Ralph Baric, Kenan Distinguished Professor of Epidemiology at UNC-Chapel Hill, led a pivotal study of the broad-spectrum antiviral.  

“We were the first to show it worked against lots of different coronaviruses in cells and culture and animal models of coronavirus disease,” Sheahan said. “The work that we did at Gillings School of Global Public Health demonstrated that molnupiravir was effective at stopping all the coronaviruses we tested in the lab including SARS-CoV-2, the cause of COVID-19, common cold causing coronaviruses and emerging coronaviruses like SARS, and MERS.” 

The oral antiviral drug works by preventing the virus from multiplying.  

“Currently the approved antivirals to treat COVID-19 have to be injected, so that limits the rollout or access to those who are sick,” Sheahan said. “The power of an oral antiviral drug is to stop people from going to the hospital.”  

Molunpiravir could fill an important role in preventing transmission and helping people who are sick, but still at home.   

“If diagnosed with COVID-19, you could immediately go to the drugstore to pick up an antiviral. If it does its job correctly it should make you less sick and shorten the duration of the disease and prevent you from transmitting the virus to others in your household,” Sheahan said 

More than a year into the pandemic, and doctors and COVID-19 patients have few treatment options. Only one drug has been authorized for use: remdesivir, a treatment used to speed recovery that UNC-Chapel Hill identified as a potential COVID-19 treatment. Unlike remdesivir, which has to be given intravenously, molnupiravir can be swallowed as a pill.  

“At UNC-Chapel Hill we have really invested in the development of preclinical compounds that look good in cells and animals, but also extended that work into the clinical space so that we can identify compounds that are safe and effective before the next outbreak,” Fischer said. “This is work that’s happening every day at Carolina. 

UNC contacts: Shantell Kirkendoll, UNC Office of Communications, and Mark Derewicz, UNC Health | UNC School of Medicine