Overview
11 DESCRIPTION Nirsevimab-alip, a respiratory syncytial virus F protein-directed fusion inhibitor, is a human immunoglobulin G1 kappa (IgG1κ) monoclonal antibody produced in Chinese hamster ovary (CHO) cells by recombinant DNA technology. The molecular weight is approximately 146.3 kDa.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action BEYFORTUS is a monoclonal antibody with anti-RSV activity [see Microbiology (12.4) ] . 12.2 Pharmacodynamics There is a positive correlation between a serum nirsevimab-alip AUC (based on clearance at baseline) above 12.8 mg*day/mL and a lower incidence of medically attended RSV lower respiratory tract infection (MA RSV LRTI). Following IM administration of nirsevimab-alip in adults, RSV neutralizing antibody levels in serum were approximately 4 times higher than baseline at 8 hours after nirsevimab-alip dosing, and maximum levels were reached by day 6 following IM administration of nirsevimab-alip in adults. The safety and effectiveness of BEYFORTUS have not been established in adults.
Indications
- 1 INDICATIONS AND USAGE BEYFORTUS is indicated for the prevention of Respiratory Syncytial Virus (RSV) lower respiratory tract disease in: Neonates and infants born during or entering their first RSV season. Children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season. BEYFORTUS is a respiratory syncytial virus (RSV) F protein-directed fusion inhibitor indicated for the prevention of RSV lower respiratory tract disease in: Neonates and infants born during or entering their first RSV season.
Common Doses
- 50 mg
- 100 mg
- 200 mg
- 0.5 mL
Dosage
2 DOSAGE AND ADMINISTRATION Administer as an intramuscular injection. ( 2.1 ) Recommended dosage: Neonates and infants born during or entering their first RSV season: 50 mg if less than 5 kg in body weight. ( 2.1 ) 100 mg if greater than or equal to 5 kg in body weight. ( 2.1 ) Children who remain vulnerable through their second RSV season: 200 mg (2 × 100 mg injections). ( 2.1 ) 2.1 Recommended Dosage First RSV Season for Neonates and Infants For neonates and infants born during the RSV season, administer BEYFORTUS starting from birth.
Contraindications
- 4 CONTRAINDICATIONS BEYFORTUS is contraindicated in infants and children with a history of serious hypersensitivity reactions, including anaphylaxis, to nirsevimab-alip or to any of the excipients [see Warnings and Precautions (5.1) and Description (11) ] . BEYFORTUS is contraindicated in infants and children with a history of serious hypersensitivity reactions, including anaphylaxis, to nirsevimab-alip or to any of the excipients. ( 4 )
Side Effects
- 6 ADVERSE REACTIONS Most common adverse reactions were rash (0.9%) and injection site reactions (0.3%). ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Sanofi at 1-855-239-3678 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 drug and may not reflect the rates observed in practice.
Interactions
- 7 DRUG INTERACTIONS 7.1 Interference with RT-PCR or Rapid Antigen Detection RSV Diagnostic Assays Nirsevimab-alip does not interfere with reverse transcriptase polymerase chain reaction (RT-PCR) or rapid antigen detection RSV diagnostic assays that employ commercially available antibodies targeting antigenic site I, II, or IV on the RSV fusion (F) protein. For immunological assay results which are negative when clinical observations are consistent with RSV infection, it is recommended to confirm using an RT-PCR-based assay.