Respiratory Syncytial Virus (RSV) Human Challenge Study of Molnupiravir in Healthy Participants (MK-4482-017)

Phase 2 Completed 116 enrolled Merck Sharp & Dohme LLC

RandomizedParallel-groupDouble-blindTreatment

Summary

This is a study of molnupiravir (MK-4482) in healthy participants who have been inoculated with an experimental Respiratory Syncytial Virus (RSV) \[RSV-A Memphis 37b\]. It is hypothesized that treatment with the drug MK-4482 (molnupiravir) will reduce the peak viral load (PVL) in the participant compared to placebo when given either before or after RSV-A Memphis 37b inoculation.

Timeline

Start: 2022-11-02
Primary completion: 2023-04-18
Completion: 2023-06-08

Outcome

Missed primary endpoint

registry Panel A: Molnupiravir Prophylaxis vs Panel C: Matched Placebo; p = 0.578 NCT05559905 ↗

registry Panel B: Molnupiravir Triggered Treatment vs Panel C: Matched Placebo; p = 0.201 NCT05559905 ↗

paper Molnupiravir was not statistically significant from placebo in either primary endpoint PMID 40175624 ↗

Publications

Results Cheng MH, Mann AJ, Maas BM, Zhao T, Bevan M, Schaeffer AK, Liao LE, Catchpole AP, Hilbert DW, Aubrey Stoch S, De Anda CS. A Phase 2a, Randomized, Placebo-Controlled Human Challenge Trial to Evaluate the Efficacy and Safety of Molnupiravir in Healthy Participants Inoculated with Respiratory Syncytial Virus. Pulm Ther. 2025 Jun;11(2):285-304. doi: 10.1007/s41030-025-00289-z. Epub 2025 Apr 2.

Drugs

Evaluation	Drug	Modality	Dose	Route
Subject	Molnupiravir	Small molecule	800 mg	Oral