ENFLONSIA

The PK of clesrovimab-cfor is approximately dose-proportional following a single IM administration of doses ranging from 20 mg to 210 mg in infants. Following IM administration of the 105 mg recommended dose, the geometric mean (% geometric CV) area under the time concentration curve from day 1 to day 150 (AUC 0-150 ) is 6,470 mcg×d/mL (22.6%), peak concentration (C max ) is 120 mcg/mL (25.4%), and the concentration at day 150 (C 150 ) is 10.3 mcg/mL (36.6%). In the first RSV season, the clesrov...

14.1 Description of Clinical Trials The efficacy and safety of ENFLONSIA were evaluated in preterm and full-term infants in the trials summarized in Table 2.

Table 2Trials Conducted with ENFLONSIA for the Prevention of Medically Attended RSV Lower Respiratory Tract Disease Trial Study Population Study Arms Participants randomized and treated GA=gestational age; CLD=chronic lung disease; CHD=hemodynamically significant congenital heart disease

Trial 004(NCT04767373) Infants born at ≥29 weeks GA from birth up to 1 year entering their first RSV season. ENFLONSIA (N=2,411) Placebo (N=1,203) 1 p...

Most common adverse reactions were injection-site erythema (3.8%), injection-site swelling (2.7%) and rash (2.3%). ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Merck Sharp & Dohme LLC at 1-877-888-4231 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another...

ENFLONSIA is contraindicated in infants with a history of serious hypersensitivity reactions, including anaphylaxis, to any component of ENFLONSIA [see Warnings and Precautions (5.1) and Description (11) ]. ENFLONSIA is contraindicated in infants with a history of serious hypersensitivity reactions, including anaphylaxis, to any component of ENFLONSIA. ( 4 )

Hypersensitivity Including Anaphylaxis: Serious hypersensitivity reactions, including anaphylaxis, have been observed with other human immunoglobulin G1 (IgG1) monoclonal antibodies. Initiate appropriate medications and/or supportive care if such reactions occur. ( 5.1 ) 5.1 Hypersensitivity Including Anaphylaxis Serious hypersensitivity reactions, including anaphylaxis, have been observed with other human immunoglobulin G1 (IgG1) monoclonal antibodies. If signs or symptoms of a clinically signi...

7 DRUG INTERACTIONS 7.1 Interference with Rapid Antigen Detection RSV Diagnostic Assays Clesrovimab-cfor may interfere with some immunologically-based RSV diagnostic assays (i.e., rapid antigen tests) as observed in laboratory studies. Confirmation using an RT-PCR assay is recommended when rapid antigen RSV diagnostic assay results are negative and clinical observations are consistent with RSV inf...