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# Merck Touts Clesrovimab Data in RSV
- URL: https://www.fdaweb.com/merck-touts-clesrovimab-data-in-rsv/
- Published: 2024-07-23T12:00:00.000Z
- Updated: 2026-09-14T14:36:10.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5157412

Merck is reporting positive topline results from its Phase 2b/3 clinical trial (MK-1654-004) evaluating clesrovimab (MK-1654), an investigational prophylactic monoclonal antibody designed to protect infants from respiratory syncytial virus (RSV) disease. Clesrovimab met its primary safety and efficacy endpoints in the trial, including reducing medically attended lower respiratory infections (MALRI) caused by RSV through Day 150\. Detailed findings of the study will be shared with FDA and other global regulatory authorities, Merck says.

Clesrovimab is described as an investigational extended half-life monoclonal antibody developed as passive immunization for preventing RSV-associated MALRI. It is being studied in infants (pre-term and full-term) to provide rapid, durable protection through their first RSV season with a single, fixed-dose administration, Merck says.