What is the proper administration and usage of Nirsevumab (targeted therapy)?

From the Guidelines

Nirsevimab should be administered as a single intramuscular injection to prevent respiratory syncytial virus (RSV) lower respiratory tract disease in infants during their first RSV season, with a recommended dosage of 50 mg for infants weighing less than 5 kg and 100 mg for those weighing 5 kg or more, as recommended by the Advisory Committee on Immunization Practices (ACIP) 1.

Key Administration Guidelines

• The injection should be given in the anterolateral aspect of the thigh by a healthcare professional before the start of RSV season or at birth for infants born during RSV season.
• Nirsevimab works by binding to the RSV fusion protein, preventing viral entry into host cells and neutralizing the virus before it can cause infection.
• Unlike palivizumab, which requires monthly injections, nirsevimab provides protection for approximately 5 months with a single dose due to its extended half-life.

Important Considerations

• Common side effects include rash, injection site reactions, and pyrexia.
• Nirsevimab is not used for treatment of established RSV infection but solely for prevention.
• Healthcare providers should ensure proper storage at 2-8°C (36-46°F), avoid freezing, and protect from light.
• The medication should be inspected for particulate matter before administration and should not be mixed with other medications.

Special Populations

• Infants aged 8–19 months who are at increased risk for severe RSV disease and entering their second RSV season should receive 1 dose of nirsevimab (200 mg, administered as two 100 mg injections given at the same time at different injection sites) 1.
• The recommendations for nirsevimab apply to infants and children recommended to receive palivizumab by the American Academy of Pediatrics (AAP) 1.

Timing of Administration

• Providers should administer nirsevimab to infants aged <8 months and to infants and children aged 8–19 months who are at increased risk for severe RSV disease beginning shortly before the start of the RSV season 1.
• In most of the continental United States, nirsevimab could be administered from October through the end of March 1.

From the FDA Drug Label

How is BEYFORTUS given • BEYFORTUS is given as an injection, usually in the thigh (leg) muscle, by your child’s healthcare provider. • Your child should receive BEYFORTUS before or during the RSV season.

The proper administration and usage of Nirsevumab is as an intramuscular injection, usually in the thigh muscle, given by a healthcare provider. It should be administered before or during the RSV season. 2

From the Research

Administration and Usage of Nirsevumab

Nirsevumab is a monoclonal antibody used for the prevention of respiratory syncytial virus (RSV) infection in infants and young children. The proper administration and usage of nirsevumab are as follows:

• Nirsevumab is administered as a single intramuscular injection at the start of the RSV season 3.
• The recommended dose of nirsevumab is 50 mg in a single intramuscular injection 3.
• Nirsevumab has been shown to be effective in preventing RSV-associated lower respiratory tract infection in healthy infants who were born preterm (29 weeks 0 days to 34 weeks 6 days of gestation) 3.
• The incidence of medically attended RSV-associated lower respiratory tract infection was 70.1% lower with nirsevumab prophylaxis than with placebo, and the incidence of hospitalization for RSV-associated lower respiratory tract infection was 78.4% lower with nirsevumab than with placebo 3.

Recommendations for Use

Nirsevumab has been recommended by the Advisory Committee on Immunization Practices (ACIP) and American Academy of Pediatrics (AAP) to be administered for:

• All infants <8 months of age 4.
• Children 8 to 19 months of age who are at increased risk for severe RSV disease 4.
• Nirsevumab is recommended to replace palivizumab for RSV prophylaxis in all eligible infants 5.

Pharmacology and Antiviral Activity

Nirsevumab targets the highly conserved site Ø of the prefusion conformation of the RSV fusion (F) protein and contains a triple amino acid substitution in the Fc domain that extends its half-life, allowing for a single dose to cover a typical RSV season in regions with temperate climates 6.

• Nirsevumab has been shown to have noninferior efficacy and safety compared with palivizumab with less frequent administration 5.