CI

At a glance

ClinicalIndex Comparison Record
Phase 2Completed· 116 enrolled
Drug / intervention
Molnupiravir +2 moredrug
Likely dose
Molnupiravir 200 mgfrom record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT05559905
NCT05559905Phase 2Completed

A Phase 2a Double-Blind, Randomized, Placebo-Controlled Study to Evaluate the Efficacy and Safety of MK-4482 in Healthy Participants Inoculated With Experimental Respiratory Syncytial Virus

Merck Sharp & Dohme LLC·interventional·Posted Sep 29, 2022·Updated Jul 18, 2025

In Brief

A Phase 2 clinical trial evaluating Molnupiravir, Placebo, and 1 other intervention for Respiratory Syncytial Virus. Completed, enrolled 116 participants across 1 site.

Detailed 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.

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
CountriesUnited Kingdom
Collaborators--

Timeline

Phase 2CompletedFinished
2023202420252026
First PostedSep 29, 2022
Enrollment StartNov 2, 2022
Primary CompletionApr 18, 2023
Study CompletionJun 8, 2023
TodayJul 2, 2026
Enrollment to primary: 6 monthsPosted 3.8 years ago

Interventions

Molnupiravirdrug

Four molnupiravir 200 mg capsules (800 mg total dose) taken twice daily by mouth.

Placebodrug

Placebo capsule matched to molnupiravir taken twice daily by mouth.

RSV A Memphis 37bbiological

RSV A Memphis 37b viral challenge given once by intranasal administration at a dosage of \~4 Log10 plaque forming units (PFUs).