UK Regulators Authorize Merck’s Molnupiravir COVID-19 Antiviral Pill

This article was originally published in ContagionLive.

Molnupiravir, the first antiviral pill for COVID-19, has been authorized in the UK.

Merck’s investigational oral ribonucleoside analog is now authorized by the UK’s Medicines and Healthcare Products Regulatory Agency (MHRA) for the treatment of mild-to-moderate COVID-19 in adults positive for SARS-CoV-2 and with ≥1 risk factor for severe disease.

The international authorization precedes decision from the US Food and Drug Administration (FDA) on Merck’s emergency use authorization (EUA) submission for molnupiravir. Which was originally designed by developers to help reduce risk of influenza severity.

The landmark authorization of molnupiravir was based on findings from an ongoing global phase 3, randomized, placebo-controlled, double-blind trial assessing the 800 mg twice-daily pill in unvaccinated adults with ≥1 risk factor associated with worse COVID-19 outcomes, who had symptom onset within 5 days prior to their trial randomization but were not hospitalized for their disease.

Investigators are seeking a primary efficacy endpoint of percentage of participants to have been hospitalized or to have died, versus placebo, from baseline to 29 days.

Common severe COVID-19 risk factors in trial participants include obesity, age >60 years, diabetes, and heart disease. Approximately 80% of all baseline SARS-CoV-2 variants have been accounted to the Delta, Gamma, and Mu variants at the time of interim analysis.

Unpublished, non-reviewed, interim data from the trial shared last month showed molnupiravir was associated with an approximate 50% reduction in composite endpoints versus at 29 days; 28 (7.3%) patients on the antiviral either died or were hospitalized, versus 53 (14.1%) patients on placebo (P = .0012). No patients administered molnupiravir had died as of the interim data report.

While US regulation is awaited for the first pill for COVID-19, Merck chief executive officer and president Robert M. Davis highlighted the “major achievement” of this initial authorization.

"In pursuit of Merck’s unwavering mission to save and improve lives, we will continue to move with both rigor and urgency to bring molnupiravir to patients around the world as quickly as possible,” Davis said in a statement.