Prescription: Beyfortus From Sanofi Pasteur, Inc

The FDA has approved Nirsevimab-alip (Beyfortus) intramuscular (IM) injection from Sanofi Pasteur, Inc, for the prevention of respiratory syncytial virus (RSV) lower respiratory tract disease (LRTD) in infants and neonates who were born during or are entering their first RSV season. The approval includes children up to age 24 months who remain vulnerable to severe RSV disease through their second RSV season.¹

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RSV can result in serious respiratory illness and is the leading cause of
hospitalization in infants younger than 12 months. Symptoms include coughing, decreased appetite, fever, runny nose, sneezing,
and wheezing.²

PHARMACOLOGY AND PHARMACOKINETICS
Nirsevimab-alip is an RSV F protein–directed fusion inhibitor. It is a recombinant human IgG1κ monoclonal antibody that provides passive immunity by targeting the prefusion conformation of the RSV F protein. Nirsevimabalip displays dose proportional pharmacokinetics after a single IM dose, with a median time of 6 days to maximum concentration and a terminal half-life of approximately 71 days.

No clinically significant differences in pharmacokinetics were observed based on race or vulnerability to severe RSV disease. Hepatic or renal
impairment is not expected to affect the pharmacokinetics of nirsevimabalip When coadministered with routine childhood vaccines, the safety and reactogenicity profile of the combined regimen was similar to the childhood vaccines alone.¹

DOSAGE AND ADMINISTRATION
The recommended dose of nirsevimab-alip for infants and neonates born during or entering their first RSV season is 50 mg IM for patients weighing less than 5 kg and 100 mg IM for those who weigh 5 kg or more. Children aged up to 24 months who remain vulnerable through their second RSV season should receive nirsevimab-alip 200 mg IM, administered as 2 doses of 100 mg each. Nirsevimab-alip is supplied as either a 50-mg/0.5 mL or a 100-mg/mL single-dose, prefilled syringe.¹

CLINICAL TRIALS
Nirsevimab-alip was evaluated in a double-blind, placebocontrolled, randomized phase 2b trial (NCT02878330) to measure the efficacy of the vaccine against medically attended LRTD caused by RSV through 150 days after vaccine administration in healthy preterm infants 29 to less than 35 weeks’ gestation. The trial met its primary end point by demonstrating a significant reduction in the incidence of medically attended RSV LRTD compared with placebo.

A double-blind, placebo-controlled, randomized phase 3 trial (MELODY, trial 04, NCT03979313) evaluated the efficacy and safety of nirsevimabalip against medically attended LRTD caused by RSV through 150 days after vaccine administration in healthy term and late preterm infants (≥ 35 weeks gestational age) who were entering their first RSV season. The trial met its primary end point by demonstrating a reduction in the incidence of medically attended RSV LRTD compared with placebo.

A double-blind, palivizumabcontrolled, randomized phase 2/3
trial (MEDLEY, trial 05, NCT03959488; Synagis; Swedish Orphan Biovitrum) assessed the safety and tolerability of nirsevimab-alip in preterm infants less than 35 weeks’ gestational age and infants with congenital heart disease and/or chronic lung disease. Serum levels of nirsevimab-alip on day151 were comparable with those observed in the MELODY trial, indicating similar protection.^1,2

CONTRAINDICATIONS, WARNINGS AND PRECAUTIONS

Nirsevimab-alip is contraindicated in patients with a history of serious hypersensitivity reactions to the medication or any of its components, including anaphylaxis.
Serious hypersensitivity reactions, including anaphylaxis, have occurred with other human immunoglobulin G1 monoclonal antibodies. If anaphylaxis or a clinically significant hypersensitivity reaction occurs, appropriate medications and/ or supportive therapy should be initiated. Caution is advised when administering nirsevimab alip to children and infants with any coagulation disorder or thrombocytopenia, or who are receiving anticoagulation therapy. The safety and effectiveness of nirsevimab-alip in children older than 24 months have not been established.

The most common adverse reactions are injection site reactions and rash.¹

About the Author

Monica Holmberg, PharmD, BCPS, is a pharmacist in Phoenix, Arizona, and a Pharmacy Times contributor.

References

1. Beyfortus. Prescribing information. Sanofi Pasteur, Inc; 2023. Accessed August 9, 2023. https://products.sanofi.us/beyfortus/beyfortus.pdf
2. FDA approves Beyfortus (nirsevimab-alip) to protect infants against RSV disease. News release. Sanofi Pasteur, Inc. July 17, 2023. Accessed August 9, 2023. https://www.sanofi.com/en/media-room/press-releases/2023/2023-07-17-17-00-00-2705911