Merck Applies EUA for Antiviral Molnupiravir




Merck (NYSE: MRK) referred to as MSD outside U.S. and Canada, and Ridgeback Biotherapeutics last Friday made it known that Molnupiravir (MK-4482, EIDD-2801), an investigational oral antiviral drug, significantly lowered the risk of hospitalization or death at an organized interim analysis of the Phase 3 Move-out trial in at risk, non-hospitalized adult patients with mild-to-moderate COVID-19. At the interim analysis, Molnupiravir lowered the hospitalization or death risk by almost 50%; 7.3% of respondents who were administered Molnupiravir either ended up hospitalized or died through Day 29 after randomization (28/385), as against 14.1% of patients on placebo-treatment; p=0.0012. Through Day 29, zero deaths were reported in those who were administered Molnupiravir, as against 8 deaths in those who were placed on placebo. Based on the recommendation of an independent Data Monitoring Committee and in consultation with the U.S. Food and Drug Administration (FDA), recruitment into the study is being halted early because of these positive results. Merck intends to file an application for Emergency Use Authorization (EUA) with the U.S. FDA as soon as possible based on these results and aims to file marketing applications with other regulatory agencies worldwide.


“More tools and treatments are urgently needed to fight the COVID-19 pandemic, which has become a leading cause of death and continues to profoundly affect patients, families, and societies and strain health care systems all around the world. With these compelling results, we are optimistic that Molnupiravir can become an important medicine as part of the global effort to fight the pandemic and will add to Merck’s unique legacy of bringing forward breakthroughs in infectious diseases when they are needed most. Consistent with Merck’s unwavering commitment to save and improve lives, we will continue to work with regulatory agencies on our applications and do everything we can to bring Molnupiravir to patients as quickly as possible,” disclosed Robert M. Davis, chief executive officer and president, Merck.

“On behalf of all of us at Merck, I thank our network of clinical investigators and patients for their essential contributions to the development of Molnupiravir.”


What does the results of the planned interim analysis represent?


The planned interim analysis analyzed data from 775 patients who were initially enlisted in the Phase 3 Move-Out trial on or prior to August 5, 2021. At the time of the resolution to halt recruitment based on the significant interim efficacy results, the trial was closing in on full recruitment of the Phase 3 sample size of 1,550 patients, with over 90% of the planned sample size already enlisted.


The criteria for eligibility required that all patients had laboratory-confirmed mild-to-moderate COVID-19, with symptom onset within 5 days of study randomization. All patients were mandated to have at least one risk factor linked to poor disease result at study entry. Molnupiravir lowered the hospitalization and/or death risk across all major subgroups; efficacy was not influenced by timing of symptom onset or underlying risk factor. Moreover, based on the respondents with available viral sequencing data (approximately 40% of participants), Molnupiravir showed consistent efficacy across viral variants Delta, Gamma and Mu.

The occurrence of any serious incident was relative in the Molnupiravir and placebo groups (35% and 40% respectively). Also, the occurrence of drug-related adverse incidence was relative (12% and 11% respectively). Fewer patients discontinued study therapy as a result of an adverse incidence in the Molnupiravir group (1.3%) as against placed on placebo.