Merck application for RSV treatment Clesrovimab for infants accepted by USFDA

The application is supported by results from the pivotal Phase 2b/3 CLEVER trial (MK-1654-004), a randomized placebo-controlled trial evaluating a single dose of clesrovimab administered to healthy preterm and full-term infants (birth to 1 year of age), and interim results from the ongoing Phase 3 SMART trial (MK-1654-007) evaluating the safety and efficacy of clesrovimab versus palivizumab in infants and children at increased risk for severe RSV disease. Data from these trials were presented during IDWeek in October 2024.

If approved, Merck anticipates that clesrovimab would be available for ordering by physicians and healthcare administrators by July 2025, with shipments to arrive in time for the 2025 RSV season.

Respiratory syncytial virus (RSV) is a contagious virus that causes widespread seasonal infections like the flu, with a worldwide burden in infants and older adults. There is high unmet need for preventative options in both healthy and high-risk infants. Globally, RSV is the leading cause of hospitalization for healthy infants under a year old, and a major cause of death in low- and middle-income countries. RSV can lead to serious respiratory conditions like bronchiolitis and pneumonia, causing an estimated 3.6 million hospitalizations and 101,000 deaths a year worldwide in children under five. According to the CDC, RSV season starts in the fall and peaks in the winter in most regions of the United States, but timing and severity in a given community or region can vary year to year.