9 hours ago
US FDA approves Merck's RSV antibody for infants
(Reuters) -The U.S. Food and Drug Administration on Monday approved Merck's preventive antibody shot to protect infants up to one year of age from respiratory syncytial virus during their first RSV season, the company said.
The United States has seen limited supply of Sanofi and AstraZeneca's antibody Beyfortus, the only preventive shot for RSV available in the country for infants and toddlers so far.
Merck's therapy, called clesrovimab and branded as Enflonsia, is a monoclonal antibody that can be administered as a single dose regardless of birth weight in healthy pre-term, full-term and at-risk infants to protect them against mild, moderate and severe RSV.
RSV is a common respiratory virus that causes seasonal infections such as the flu, but is a leading cause of pneumonia and death in infants and older adults.
The approval was based on results from a late-stage trial in which Enflonsia had a comparable safety profile to Swedish Orphan Biovitrum's Synagis, a monthly injection.
Merck said that Enflonsia is the first and only RSV preventive option administered to infants using the same dose regardless of weight, and it told Reuters the drug will be priced at $556 per dose.
Jefferies analyst Akash Tewari said last year that this is beneficial since physicians have to forecast an infant's potential weight during RSV season with Beyfortus, which makes dose ordering and inventory more complex.
In the U.S., an estimated 58,000–80,000 children younger than five years are hospitalized due to RSV each year, according to the U.S. Centers for Disease Control and Prevention.
The CDC currently recommends two immunization options for babies to be protected from severe RSV — an RSV vaccine given to the mother during pregnancy or an RSV antibody given to the baby.
Merck expects the drug's shipments to arrive in time for the 2025-2026 RSV season.
The CDC's Advisory Committee on Immunization Practices is expected to meet later this month to discuss and make recommendations for the use of Enflonsia in infants.
