Merck and Ridgeback Biotherapeutics Provide Update on Progress of Clinical Development Program for Molnupiravir, an Investigational Oral Therapeutic for the Treatment of Mild-to-Moderate COVID-19

Merck (NYSE: MRK), known as MSD outside the United States and Canada, and Ridgeback Biotherapeutics today provided an update on the clinical development program for molnupiravir (MK-4482/ EIDD-2801), an investigational orally available antiviral therapeutic. Based on a planned interim analysis of data from the Phase 2, dose-finding portion (Part 1) of two ongoing placebo-controlled Phase 2/3 trials evaluating molnupiravir administered twice a day for five days in outpatients (MOVe-OUT) and hospitalized patients (MOVe-IN) with COVID-19, and from a previously completed Phase 2a dose-ranging study in outpatients, the decision has been made to proceed with the Phase 3 portion (Part 2) of MOVe-OUT in outpatients with COVID-19, evaluating the 800 mg dose of molnupiravir twice daily. Data from MOVe-IN indicate that molnupiravir is unlikely to demonstrate a clinical benefit in hospitalized patients, who generally had a longer duration of symptoms prior to study entry; therefore, the decision has been made not to proceed to Phase 3.

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“We continue to make progress in the clinical development of our antiviral candidate molnupiravir. Data from the dose-finding portion of these studies are consistent with the mechanism of action and provide meaningful evidence for the antiviral potential of the 800 mg dose,” said Dr. Roy Baynes, senior vice president and head of global clinical development, chief medical officer, Merck Research Laboratories. “Based on the findings of this study we are advancing a Phase 3 trial program in non-hospitalized patients that strategically leverages our large network of clinical sites to enroll appropriate patients globally.”

“We are pleased that molnupiravir continues to show promise as a potential treatment for non-hospitalized patients with COVID-19,” said Wendy Holman, Chief Executive Officer, Ridgeback Biotherapeutics. “Data from Ridgeback Bio’s EIDD-2801-2003 study (MK-4482-006) coupled with Merck’s MK-4482-002 study provide compelling evidence for the antiviral activity of molnupiravir. We look forward to the initiation and completion of the Phase 3 portion of the MOVe-OUT study.”

Update on MOVe-OUT (MK-4482-002) and MOVe-IN (MK-4482-001)

MOVe-OUT is an ongoing Phase 2/3, randomized, placebo-controlled, double-blind, multi-site study evaluating the efficacy, safety and pharmacokinetics of orally administered molnupiravir in non-hospitalized participants with COVID-19 confirmed using polymerase chain reaction. The primary efficacy objective of MOVe-OUT is to evaluate the efficacy of molnupiravir compared to placebo as assessed by the percentage of patients who are hospitalized and/or die from the time of randomization through Day 29. Part 1 of MOVe-OUT enrolled a total of 302 participants, with symptom onset within seven days prior to randomization, who were assigned to receive molnupiravir 200 mg (75), 400 mg (77), or 800 mg (76), or placebo (74).