MSD (Merck & Co) has reported positive topline results from its Phase IIb/III MK-1654-004 clinical trial assessing clesrovimab as a preventative treatment for respiratory syncytial virus (RSV) in infants.

The double-blind, randomised, placebo-controlled study was designed to assess the safety and efficacy of clesrovimab.

Discover B2B Marketing That Performs

Combine business intelligence and editorial excellence to reach engaged professionals across 36 leading media platforms.

Find out more

Participants, including healthy preterm and full-term infants, were randomly assigned to receive a single dose of clesrovimab or a placebo.

The occurrence of RSV-linked, medically attended lower respiratory infection (MALRI) from day one post-dosing to day 150, in comparison to the placebo group, was one of the primary endpoints of the trial.

Safety was another primary endpoint, with safety measures evaluating the percentage of subjects having injection-related adverse events (AEs), AEs of special interest (AESIs), solicited systemic AEs, or serious adverse events (SAEs).

The trial findings indicated that clesrovimab met all primary safety and efficacy endpoints.

GlobalData Strategic Intelligence

US Tariffs are shifting - will you react or anticipate?

Don’t let policy changes catch you off guard. Stay proactive with real-time data and expert analysis.

By GlobalData

It was also found to be effective in reducing the instances of MALRI caused by RSV up to day 150.

MSD is preparing detailed results for presentation and intends to submit the data to global regulatory authorities.

Clesrovimab (MK-1654) is an investigational extended half-life monoclonal antibody developed for passive immunisation. It is intended to prevent RSV-associated MALRI in infants, offering rapid and lasting protection through their first RSV season with a single, fixed-dose administration.

Merck Research Laboratories global clinical development infectious diseases and vaccines senior vice-president Dr Paula Annunziato said: “RSV is highly contagious and can cause inflammation in the airways of infants, leading to difficulty breathing. As a widespread illness globally, RSV is the leading cause of hospitalisation for healthy infants.

“We are encouraged by these findings and look forward to working with regulators to provide a new option to help address the impact of RSV on infants and their families.”

MSD has concluded the acquisition of Eyebiotech (EyeBio), making the privately held UK-based biotech its subsidiary.

Clinical Trials Arena Excellence Awards - The Benefits of Entering

Gain the recognition you deserve! The Clinical Trials Arena Excellence Awards celebrate innovation, leadership, and impact. By entering, you showcase your achievements, elevate your industry profile, and position yourself among top leaders driving clinical trials industry advancements. Don’t miss your chance to stand out—submit your entry today!

Nominate Now