Merck and Ridgeback Start Phase 3 Study of LAGEVRIO™ for High-Risk COVID-19 Adults

Merck, known as MSD outside the US and Canada, has commenced the Phase 3 MOVe-NOW clinical trial to assess LAGEVRIO™ (molnupiravir), an experimental oral antiviral medication, for treating adults with COVID-19 who are at a high risk of serious disease progression. This global, double-blind, placebo-controlled trial is targeting adults aged 18 and over who have tested positive for SARS-CoV-2, have shown COVID-19 symptoms for four days or less, and are not hospitalized. The study is focused on individuals unable to use nirmatrelvir/ritonavir (NMV/r) due to drug interactions, allergies, previous adverse reactions, or unavailability.

The trial will use a new formulation of LAGEVRIO involving two smaller 400-mg tablets per dose (four daily tablets) compared to the current four 200-mg capsules per dose (eight daily capsules). These smaller tablets are not yet approved for use in any country. For more information on the trial, visit clinicaltrials.gov.

Dr. Paula Annunziato, Senior Vice President of Infectious Diseases and Vaccines at Merck Research Laboratories, emphasized the ongoing global impact of COVID-19 and the potential of LAGEVRIO to offer significant benefits, particularly for individuals at higher risk of severe outcomes due to age, multiple comorbidities, or immunocompromising conditions.

LAGEVRIO has already been approved or authorized for use in various countries, including Japan and Australia, and is available under emergency use authorization in the United States for certain adults diagnosed with COVID-19. To date, over 8.3 million people worldwide have used LAGEVRIO.

The MOVe-NOW study (MK-4482-023, NCT06667700) is a Phase 3, multicenter, randomized, double-blind, placebo-controlled investigation designed to evaluate the efficacy and safety of orally administered LAGEVRIO compared with placebo in non-hospitalized adults at high risk of disease progression. Approximately 3,082 participants will be enrolled and randomized to receive either LAGEVRIO (800 mg) or placebo orally every 12 hours for five days. Participants must be at least 18 years old, have a positive SARS-CoV-2 test, and show COVID-19 symptoms for four days or less. Participants who are ineligible for nirmatrelvir/ritonavir due to various reasons will be included. The study is being conducted across 25 markets globally, including the United States, Japan, Korea, Taiwan, the United Kingdom, France, Italy, Spain, Ukraine, Poland, Mexico, and Colombia, among others.

In some cases, investigators may opt to treat participants with concomitant remdesivir if it is available and clinically appropriate, in addition to LAGEVRIO or placebo. The trial aims to ensure vulnerable individuals have timely access to remdesivir as standard care.

Primary efficacy and safety endpoints include the percentage of participants hospitalized or deceased for any reason or having a COVID-19-related medically-attended visit through Day 29, the percentage of participants with adverse events, and the percentage of participants discontinuing LAGEVRIO due to adverse events. A key secondary endpoint is the sustained alleviation without relapse of selected participant-reported COVID-19 signs and symptoms through Day 29. Additional secondary endpoints involve assessing SARS-CoV-2 viral load, the time to sustained resolution of symptoms without relapse, and the percentage of participants requiring significant medical interventions due to COVID-19.

The study includes an extended follow-up of approximately five and a half months post-treatment to evaluate endpoints associated with post-acute sequelae of COVID-19 (PASC or long COVID). Development of PASC will be assessed on Day 29 and during the extended follow-up period based on self-reported COVID-19 signs/symptoms.