Preclinical studies demonstrate Merck’s oral antiviral molnupiravir effective against COVID-19 Omicron variant

Citing data from six preclinical studies, Merck and Ridgeback Biotherapeutics last week announced that their oral antiviral COVID-19 medicine, molnupiravir, maintained efficacy against the widespread Omicron variant.

These in vitro lab studies were independently organized and conducted by researchers in six countries: Belgium, Czech Republic, Germany, Poland, the Netherlands, and the United States. Currently authorized for emergency use in more than 10 countries, including the United States, molnupiravir was investigated for the antiviral activity it produced against SARS-CoV-2 variants, alongside other COVID-19 antiviral agents.

“These findings from multiple independent in vitro studies showing that molnupiravir has consistent antiviral activity against Omicron, the primary variant circulating globally, provide additional confidence in the potential of molnupiravir as an important treatment option for certain adults with mild to moderate COVID-19 who are at high risk for progressing to severe disease,” Dr. Dean Y. Li, president of Merck Research Laboratories, said. “We are grateful to these investigators for these important insights and to our own colleagues who are working with global regulatory authorities to ensure that molnupiravir is widely accessible to appropriate patients.”

Previously, molnupiravir has been tested and provided generally consistent efficacy against variants including Delta, Gamma, and Mu. However, full clinical studies have yet to confirm its effectiveness against Omicron. These preclinical are the first step toward that. Nevertheless, the data prompted optimistic statements from both companies.

“Based on its mechanism of action, along with these new findings demonstrating in vitro activity across multiple variants, including Omicron, we anticipate that molnupiravir will continue to be active against variants of concern and an important tool in the fight against COVID-19,” Wendy Holman, CEO of Ridgeback Biotherapeutics, said.

The companies produce 10 million courses of molnupiravir by the end of 2021. Another 20 million courses are expected this year, including 2 million to be shipped to the U.S. government. Another 3 million courses have been guaranteed for low- and middle-income countries during the first half of this year through an agreement with UNICEF.