Merck and Ridgeback Announce FDA Emergency Use Authorization for Oral Antiviral Molnupiravir for Treatment of Mild-to-Moderate COVID-19

On December 23, Merck & Co., Inc. / Ridgeback announced that the oral COVID-19 drug Molnupiravir (MK-4482/EIDD-2801) had received emergency use authorization from the U.S. FDA for the treatment of adult patients with mild to moderate COVID-19. These patients tested positive for SARS-CoV-2 and have at least one risk factor for developing severe illness.

Notably, on November 4, 2021, MSD/Ridgeback announced that the UK Medicines and Healthcare products Regulatory Agency (MHRA) had approved molnupiravir for use in the UK to treat adult patients with mild to moderate COVID-19 who are at risk of severe disease and hospitalization. Molnupiravir is the world’s first orally administered antiviral drug approved for the treatment of mild to moderate COVID-19 in adults.

The FDA's Emergency Use Authorization for Molnupiravir is primarily based on the positive interim analysis results from the Phase III MOVe-OUT study as well as recently updated data. The interim analysis showed that the hospitalization/death rates within 29 days were 7.3% in the molnupiravir group and 14.1% in the placebo group. The risk of hospitalization and death in the molnupiravir group was reduced by 50%, with no deaths reported within 29 days, while eight deaths were reported in the placebo group.

On November 26, additional analysis data for all participants (n=1433) showed that molnupiravir reduced the risk of hospitalization or death from 9.7% (68/699) in the placebo group to 6.8% (48/709) in the molnupiravir group, with an absolute risk reduction of 3.0% (p=0.0218) and a relative risk reduction of 30% (HR: 0.70). There were 9 deaths in the placebo group and 1 death in the molnupiravir group.

On November 30, the Antimicrobial Drugs Advisory Committee (AMDAC) of the U.S. FDA voted 13 in favor and 10 against to positively support the Emergency Use Authorization (EUA) application for Molnupiravir. The advisory committee concluded that the known and potential benefits outweigh the unknown and potential risks for high-risk adult patients with mild to moderate COVID-19 who receive molnupiravir treatment within five days of symptom onset.

In addition, MSD recently announced that it would share its antiviral drug Molnupiravir for treating COVID-19 with developing countries, expanding the use of this promising treatment. Meanwhile, MSD and its partner Ridgeback Biotherapeutics stated that they have reached a landmark "royalty-free licensing agreement" with the Medicines Patent Pool (MPP), supported by the United Nations, to share the drug with 105 low-income and middle-income countries. This is the first MPP agreement providing access to medical technology for COVID-19. According to the agreement, as long as COVID-19 remains classified by the World Health Organization as a Public Health Emergency of International Concern, MSD will not collect patent royalties from the sales of Molnupiravir.

Background Information

Molnupiravir (MK-4482, EIDD-2801) is an investigational, orally administered potent ribonucleoside analog that inhibits the replication of SARS-CoV-2, the causative agent of COVID-19. Molnupiravir has been shown to have positive effects on the prevention, treatment, and blocking of transmission across multiple SARS-CoV-2 variants. Preclinical data indicate that Molnupiravir poses a high barrier to resistance development.

Molnupiravir was developed by Drug Innovation Ventures at Emory (DRIVE), a non-profit biotechnology company fully owned by Emory University, which received research funding from the U.S. Department of Defense and the National Institutes of Health. Currently, Molnupiravir is being jointly developed by MSD and Ridgeback. Ridgeback has received an upfront payment from MSD and is eligible to receive milestone payments based on specific development and regulatory approval progress. All profits generated from the collaboration will be equally shared between the two parties. Since the licensing agreement with Ridgeback, all funds for the development of Molnupiravir have been provided by MSD and Ridgeback.