New Studies Support Benefit of Merck's Molnupiravir

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Three studies supporting Merck and Ridgeback Biotherapeutics’ Lagevrio (molnupiravir) will be presented at the European Congress of Clinical Microbiology & Infectious Diseases (ECCMID 2022) in Lisbon. The conference runs from April 23-26. Molnupiravir is an oral antiviral authorized in the U.S. and other countries for early treatment of COVID-19.

One study demonstrated that the drug is effective at reducing the risk of progression of COVID-19 in non-hospitalized, unvaccinated patients at high risk of poor outcomes. This is data from the Phase II/III MOVe-OUT trial published in the New England Journal of Medicine in December 2021.

Participants had at least one COVID-19 symptom and were dosed within five days of the symptom appearing. They completed a 15-item daily symptom diary from day one until day 29, rating the severity of each symptom as none, mild, moderate or severe, excluding loss of smell or taste, which were rated as yes or no.

The authors wrote, “In this study, we observed a positive impact of molnupiravir treatment on the outcome for most patient-reported COVID-19 symptoms compared to placebo, supporting the treatment benefits of molnupiravir for non-hospitalized patients with COVID-19 in the early stages of their symptoms.”

A second study was conducted on immunocompromised patients. It was also based on data from the MOVe-OUT trial, published in December in NEJM. All patients received the drug within five days of reporting symptoms.

Immunocompromised patients were identified based on previous or ongoing medication use and medical history. This included patients with cancer, HIV, those using immunosuppressant drugs and transplant patients. Out of the 1,433 participants in the MOVe-OUT trial, 4% were immunocompromised. In the group receiving molnupiravir, only 8% of the immunocompromised patients were hospitalized or experienced fatal adverse events by day 29, compared to 25% in the placebo group.

“Immunocompromised participants receiving molnupiravir in the MOVe-OUT trial demonstrated a lower incidence of hospitalization or death by day 29 compared to those receiving placebo, and molnupiravir was generally well-tolerated,” the authors wrote. “Reductions in the amount of SARS-CoV-2 virus over time were similar in immunocompromised and non-immunocompromised participants, and no infectious virus was detected after baseline in the molnupiravir group, suggesting that molnupiravir stops viral replication equally well in both the immunocompromised and immunocompetent patients in our trial population.”

The third to be presented at ECCMID is based on the Phase II/III MOVe-OUT trial, already published in NEJM. The drug demonstrated superiority over placebo in non-hospitalized adults with mild or moderate COVID-19 at risk of progression to severe disease. This was dependent upon patients starting the medication within five days of onset of symptoms.

PCR testing was conducted to determine viral loads from nasopharyngeal swabs collected on days 1, 3, 5, 10, 15 and 29. Day 1 was the baseline, and day 5 was the end-of-treatment visit. On day 3, infectious SARS-CoV-2 was not observed in any of the 92 participants with an infectious virus at day 1 who received molnupiravir, compared to 21.8% of the placebo group. On day 5, SARS-CoV-2 was observed in 0.0% in the molnupiravir cohort, compared to 2.2% in the placebo group. By day 10, no virus was detected in either arm of the study.

“This analysis of the final virologic outcome data from MOVe-OUT confirms previous observations demonstrating that a five-day treatment course of twice-daily 800 mg molnupiravir results in a more rapid decline in viral RNA and faster elimination of infectious virus than placebo,” said Dr. Julie Strizki, Senior Principal Scientist with Merck. “This study provides additional evidence that molnupiravir helps those infected clear SARS-CoV-2 faster than placebo and supports MOVe-OUT’s primary finding that molnupiravir can lower the risk of progression to serious illness in this high-risk cohort.”