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BEYFORTUS

nirsevimab · Injection

Prescription Biologic BLA Official labelling
Informational index, not medical advice. Content is reproduced from public FDA and NLM data. Always confirm against the manufacturer's current prescribing information. Report adverse events to FDA MedWatch.

Overview

Brand name
BEYFORTUS
Generic name
nirsevimab
Dosage form
Injection
Route
Intramuscular
Marketing category
BLA · BLA
Labeler
Sanofi Vaccines US Inc.
Product type
Human Prescription Drug
DEA schedule
Not scheduled
Active ingredients
1
NDC product codes
2
Packages
4
Data completeness
74% of corroborating sources present

Active ingredients

Source: NDC Directory
Active ingredients and strengths as listed in the NDC Directory.
Ingredient Strength RxCUI Monograph
Nirsevimab 100 mg/mL 2642406 —

Forms, strengths and routes

Source: NDC Directory
Dosage form
Injection
Route of administration
Intramuscular
Presentations
6

Pharmacologic classes are listed in the class section below.

Pharmacologic class

Source: NDC Directory
Established pharmacologic classes (EPC), mechanisms of action (MoA), chemical structures (CS) and physiologic effects (PE).
Class Type Browse
Fusion Protein Inhibitors [MoA] MoA 1 member — no class page
Respiratory Syncytial Virus Anti-F Protein Monoclonal Antibody [EPC] EPC 1 member — no class page

Regulatory status

Source: Drugs@FDANDC Directory
Application number
761328
Application type
BLA · Biologics License Application
Approval date
July 17, 2023
Sponsor
ASTRAZENECA AB
Products on application
2
Submissions recorded
5
Products approved under application 761328.
Product Trade name Form Strength Ingredient Status TE Flags
761328-001 BEYFORTUS INJECTABLE NIRSEVIMAB-ALIP Prescription —
761328-002 BEYFORTUS INJECTABLE NIRSEVIMAB-ALIP Prescription —

Approval history

Source: Drugs@FDA
Most recent submissions on application 761328.
Type No. Action Status Date Review
Supplement 19 Labeling Approved April 7, 2026 Standard
Supplement 12 Efficacy Approved October 20, 2025 Standard
Supplement 5 Efficacy Approved August 22, 2024 Standard
Supplement 7 Labeling Approved February 23, 2024 901 Required
Original application 1 Type 1 - New Molecular Entity Approved July 17, 2023 Standard

Review documents

  • 0 · Supplement · April 10, 2026
  • 0 · Supplement · April 9, 2026
  • 0 · Supplement · October 21, 2025
  • 0 · Supplement · October 21, 2025
  • 0 · Supplement · August 26, 2024
  • 0 · Supplement · August 23, 2024
  • 0 · Supplement · February 26, 2024
  • 0 · Supplement · February 26, 2024
  • 0 · Original application · August 15, 2023
  • 0 · Original application · July 18, 2023
  • 0 · Original application · July 18, 2023

Prescribing information

Source: openFDA Drug Labeling

Reproduced verbatim from the Structured Product Labeling submitted to the FDA (effective 20260713). This is the manufacturer's labelling text, not a summary and not advice.

HUMAN PRESCRIPTION DRUG · 20260713

Indications and Usage

openFDA Drug Labeling

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. ( 1 ) Children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season. ( 1 )

Dosage and Administration

openFDA Drug Labeling

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. For neonates and infants born outside the RSV season, administer BEYFORTUS once prior to the start of the RSV season considering duration of protection provided by BEYFORTUS [see Clinical Pharmacology (12.2) ] . The recommended dosage of BEYFORTUS for neonates and infants born during or entering their first RSV season is based on body weight (see Table 1 ) and is administered as a single intramuscular (IM) injection. Table 1 Recommended Dosage of BEYFORTUS for the First RSV Season Body Weight at Time of Dosing Recommended Dosage Less than 5 kg 50 mg by IM injection 5 kg and greater 100 mg by IM injection Second RSV Season for Children Who Remain at Increased Risk for Severe RSV Disease For children up to 24 months of age, regardless of body weight, who remain at increased risk for severe RSV disease in their second RSV season, refer to Table 2 below for recommended dosage. Table 2 Recommended Dosage of BEYFORTUS for the Second RSV Season for Children Who Remain at Increased Risk for Severe RSV Disease Child's Age at Time of Dosing Recommended Dosage Up to 24 months of age Regardless of body weight 200 mg administered as two IM injections of (2 × 100 mg) First and Second RSV Season for Children Undergoing Cardiac Surgery with Cardiopulmonary Bypass For children undergoing cardiac surgery with cardiopulmonary bypass, an additional dose of BEYFORTUS is recommended as soon as the child is stable after surgery to ensure adequate nirsevimab-alip serum levels. The recommended dosage of BEYFORTUS is administered as an IM injection. First RSV season: If surgery is within 90 days after receiving BEYFORTUS, the additional dose should be based on body weight at the time of the additional dose. Refer to Table 1 for weight-based dosing. If more than 90 days have elapsed since receiving BEYFORTUS, the additional dose should be 50 mg regardless of body weight. Second RSV season: If surgery is within 90 days after receiving BEYFORTUS, the additional dose should be 200 mg, regardless of body weight. If more than 90 days have elapsed since receiving BEYFORTUS, the additional dose should be 100 mg, regardless of body weight. 2.2 Administration Instructions BEYFORTUS must be administered by a healthcare provider. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. BEYFORTUS is a clear to opalescent, colorless to yellow solution. Do not inject BEYFORTUS if the liquid is cloudy, discolored, or it contains large particles or foreign particulate matter. Do not use if the BEYFORTUS pre-filled syringe has been dropped or damaged, the security seal on the carton has been broken, or the expiration date has passed. BEYFORTUS is available in a 50 mg and a 100 mg pre-filled syringe. Check the labels on the BEYFORTUS carton and pre-filled syringe to ensure the correct 50 mg or 100 mg product is being used. Co-administration with Childhood Vaccines and Immunoglobulin Products BEYFORTUS can be given concomitantly with childhood vaccines [see Clinical Pharmacology (12.3) ] . When administered concomitantly with injectable vaccines, they should be given with separate syringes and at different injection sites. Do not mix BEYFORTUS with any vaccines or medications in the same syringe or vial. There is no information regarding co-administration of BEYFORTUS with other immunoglobulin products. Palivizumab should not be administe …

Dosage Forms and Strengths

openFDA Drug Labeling

3 DOSAGE FORMS AND STRENGTHS BEYFORTUS is a clear to opalescent, colorless to yellow solution available as follows: Injection: 50 mg/0.5 mL in a single-dose pre-filled syringe. Injection: 100 mg/mL in a single-dose pre-filled syringe. Injection: 50 mg/0.5 mL in a single-dose pre-filled syringe. ( 3 ) 100 mg/mL in a single-dose pre-filled syringe. ( 3 )

Contraindications

openFDA Drug Labeling

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 )

Warnings and Cautions

openFDA Drug Labeling

5 WARNINGS AND PRECAUTIONS Hypersensitivity Reactions Including Anaphylaxis: Serious hypersensitivity reactions have been reported following BEYFORTUS administration. These reactions included urticaria, dyspnea, cyanosis, and/or hypotonia. Anaphylaxis has been observed with human immunoglobulin G1 (IgG1) monoclonal antibodies. If signs and symptoms of anaphylaxis or other clinically significant hypersensitivity reactions occur, initiate appropriate treatment. ( 5.1 ) 5.1 Hypersensitivity Reactions Including Anaphylaxis Serious hypersensitivity reactions have been reported following BEYFORTUS administration. These reactions included urticaria, dyspnea, cyanosis, and/or hypotonia. Anaphylaxis has been observed with human immunoglobulin G1 (IgG1) monoclonal antibodies. If signs and symptoms of anaphylaxis or other clinically significant hypersensitivity reactions occur, initiate appropriate treatment. 5.2 Use in Individuals with Clinically Significant Bleeding Disorders As with any other IM injections, BEYFORTUS should be given with caution to infants and children with thrombocytopenia, any coagulation disorder, or to individuals on anticoagulation therapy.

Adverse Reactions

openFDA Drug Labeling

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. A total of 3,224 pediatric subjects received the recommended dose of BEYFORTUS in Phase 2 and Phase 3 clinical trials (Trials 03, 04, and 05) including 2,119 infants who were born at 35 weeks gestational age (GA) or older, and 1,105 infants who were born at less than 35 weeks GA. A total of 247 infants of any GA with chronic lung disease (CLD) of prematurity or hemodynamically significant congenital heart disease (CHD) in Trial 05 received the recommended dose of BEYFORTUS. Neonates and Infants Entering Their First RSV Season (Trial 03 and Trial 04) Trial 03 was a randomized, double-blind placebo-controlled trial conducted in preterm infants born at a GA of greater than or equal to 29 weeks to less than 35 weeks. Subjects were randomized 2:1 to receive BEYFORTUS (N=968) or placebo (N=479) by IM injection. All subjects randomized to BEYFORTUS received a single 50 mg IM dose regardless of body weight. Safety data in Trial 03 are presented only for the infants in the BEYFORTUS arm who received the recommended dose [infants who weighed less than 5 kg and who received a single dose of 50 mg BEYFORTUS IM (N=572) or placebo (N=288)]. Trial 04 was a Phase 3, randomized, double-blind, placebo-controlled trial conducted in late preterm and term infants born at greater than or equal to 35 weeks GA. Trial 04 enrolled subjects sequentially into two cohorts: the Primary Cohort was used for the primary efficacy analysis [see Clinical Studies (14.3) ] and for assessment of safety, and the Safety Cohort was used primarily for safety assessment. All subjects from both cohorts of Trial 04 were included in the safety analysis (BEYFORTUS N=1,997 and placebo N=997). Subjects in Trial 04 weighing less than 5 kg received a single 50 mg IM dose of BEYFORTUS and infants weighing greater than or equal to 5 kg received a single 100 mg IM dose. Infants who received the recommended dose in Trial 03 and infants in Trial 04 were pooled to evaluate the safety of BEYFORTUS (N=2,570) compared to placebo (N=1,284). At randomization, in this pooled Safety Population from Trials 03 and 04 cohorts, 22% of infants were born at less than 35 weeks GA, 10% of infants were GA greater than or equal to 35 weeks and less than 37 weeks; 68% were GA greater than or equal to 37 weeks; 52% were male; 57% were White; 15% were Black; 4% were American Indian/Alaskan native; 4% were Asian; 1% were Pacific Islander; and 19% were Other or Mixed Race; 30% were Hispanic or Latino; 73% were from Northern Hemisphere; and 53% weighed less than 5 kg. The median age was 2 months; 65% were less than or equal to 3 months; 28% were greater than 3 to less than or equal to 6 months, and 7% were greater than 6 months of age. (Refer to Sections 14.2 and 14.3, Clinical Studies, for a description of the efficacy populations in Trials 03 and 04). In both trials, infants received a single dose of IM BEYFORTUS or placebo on Study Day 1 and were monitored for at least 60 minutes post-dose. Subjects were followed for 360 days post-dose to assess safety. Adverse reactions were reported in 1.2% of subjects who received BEYFORTUS; most (97%) of adverse reactions were mild to moderate in intensity. Table 3 summarizes the adverse reactions that occurred in Trial 03 and Trial 04 (Safety Population) in subjects who received the recommended dose of BEYFORTUS. Table 3 Adverse Reactions Reported at an Incidence Higher Than Placebo in the Safety Population The Safety Population includes all subj …

Drug Interactions

openFDA Drug Labeling

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.

Use in Specific Populations

openFDA Drug Labeling

8 USE IN SPECIFIC POPULATIONS The safety and effectiveness of BEYFORTUS in children older than 24 months of age have not been established. ( 8.4 ) 8.1 Pregnancy BEYFORTUS is not indicated for use in females of reproductive potential. 8.2 Lactation BEYFORTUS is not indicated for use in females of reproductive potential. 8.4 Pediatric Use The safety and effectiveness of BEYFORTUS have been established for the prevention of RSV lower respiratory tract disease in neonates and infants born during or entering their first RSV season and in children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season. The safety and efficacy of BEYFORTUS for this indication and populations are discussed throughout the labeling. Use of BEYFORTUS for this indication is supported by evidence from adequate and well-controlled studies in neonates and infants from birth up to 12 months of age with additional pharmacokinetic and safety data in children up to 24 months of age [see Adverse Reactions (6.1) , Clinical Pharmacology (12.3) , and Clinical Studies (14) ]. Use of BEYFORTUS in this population is supported by the following: - Trial 03, a randomized, double-blind, placebo-controlled multicenter trial for the prevention of MA RSV LRTI conducted in preterm infants born at GA greater than or equal to 29 weeks and less than 35 weeks entering their first RSV season; - Trial 04, a double-blind, placebo-controlled multicenter trial, for the prevention of MA RSV LRTI in term and late preterm infants GA greater than or equal to 35 weeks entering their first RSV season; - Trial 05, a Phase 2/3 randomized, double-blind, palivizumab-controlled multicenter trial in pediatric subjects born less than 35 weeks GA and infants with CLD of prematurity or hemodynamically significant CHD entering their first or second RSV season. In addition, BEYFORTUS was evaluated in an open-label, uncontrolled, single-dose trial (Trial 08) in 100 infants and children who were less than or equal to 24 months of age, who received BEYFORTUS in their first or second RSV season, and who had a wide variety of underlying diseases or treatments resulting in immune compromise. The safety profile of BEYFORTUS administered in Trial 08 was consistent with the safety profile of other trials of BEYFORTUS in infants and children [see Clinical Pharmacology (12.3) ]. Trial 09 is a Phase 3b randomized, open-label trial of BEYFORTUS compared to no intervention for the prevention of hospitalization in term and preterm infants (GA greater than or equal to 29 weeks) born during or entering their first RSV season [see Adverse Reactions (6.1) and Clinical Studies (14.5) ]. The safety and effectiveness of BEYFORTUS have not been established in children older than 24 months of age.

Mechanism of Action

openFDA Drug Labeling

12.1 Mechanism of Action BEYFORTUS is a monoclonal antibody with anti-RSV activity [see Microbiology (12.4) ] .

Description

openFDA Drug Labeling

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. BEYFORTUS (nirsevimab-alip) injection is a sterile, preservative-free, clear to opalescent, colorless to yellow solution for intramuscular injection. It is supplied in a single-dose siliconized Luer lock Type I glass pre-filled syringe with a FluroTec coated plunger stopper. Each 0.5 mL contains 50 mg nirsevimab-alip, arginine hydrochloride (8 mg), histidine (1.1 mg), L-histidine hydrochloride monohydrate (1.6 mg), polysorbate 80 (0.1 mg), sucrose (21 mg), and water for injection (USP). The pH is 6.0. Each 1 mL contains 100 mg nirsevimab-alip, arginine hydrochloride (17 mg), histidine (2.2 mg), L-histidine hydrochloride monohydrate (3.3 mg), polysorbate 80 (0.2 mg), sucrose (41 mg), and water for injection (USP). The pH is 6.0.

10 OVERDOSAGE There is limited experience of overdose with BEYFORTUS. There is no specific treatment for an overdose with BEYFORTUS. In the event of an overdose, the individual should be monitored for the occurrence of adverse reactions and provided with symptomatic treatment as appropriate.

How Supplied / Storage and Handling

openFDA Drug Labeling

16 HOW SUPPLIED/STORAGE AND HANDLING How Supplied BEYFORTUS injection is a sterile, preservative-free, clear to opalescent, colorless to yellow solution supplied as follows: One 50 mg/0.5 mL single-dose pre-filled syringe in a carton: NDC 49281-575-00 Five 50 mg/0.5 mL single-dose pre-filled syringes in a carton: NDC 49281-575-15 One 100 mg/mL single-dose pre-filled syringe in a carton: NDC 49281-574-88 Five 100 mg/mL single-dose pre-filled syringes in a carton: NDC 49281-574-15 Each BEYFORTUS pre-filled syringe is for one time use only. Storage and Handling Store refrigerated between 36°F to 46°F (2°C to 8°C). BEYFORTUS may be kept at room temperature 68°F to 77°F (20°C to 25°C) for a maximum of 48 hours. After removal from the refrigerator, BEYFORTUS must be used within 48 hours or discarded. Store BEYFORTUS in original carton to protect from light until time of use. Do not freeze. Do not shake. Do not expose to heat.

Adverse event reports

Source: openFDA FAERS
1,721
FAERS reports mentioning this drug
as of 2026-09-25T03:42:24+00:00
A report count is not a risk measure. FAERS accepts voluntary and mandatory reports without establishing causation, and reporting is influenced by how widely a drug is used, how long it has been marketed, and media attention. FDA states that reports “do not prove that the drug caused the event”. Compare rates, not totals.

Attributed to this product's most-reported active ingredient: NIRSEVIMAB. Combination products with more than six active ingredients are not attributed, because a report count summed across a long ingredient list measures the list, not the medicine.

Packaging and NDCs

Source: NDC Directory
Every National Drug Code package associated with this medication. The NDC is the identifier used for dispensing, billing and pharmacovigilance in the United States.
Package NDC Product NDC Labeler Description Marketing start
49281-574-15 49281-574 Sanofi Vaccines US Inc. 5 SYRINGE in 1 CARTON (49281-574-15) / 1 mL in 1 SYRINGE July 18, 2023
49281-574-88 49281-574 Sanofi Vaccines US Inc. 1 SYRINGE in 1 CARTON (49281-574-88) / 1 mL in 1 SYRINGE July 18, 2023
49281-575-00 49281-575 Sanofi Vaccines US Inc. 1 SYRINGE in 1 CARTON (49281-575-00) / .5 mL in 1 SYRINGE July 18, 2023
49281-575-15 49281-575 Sanofi Vaccines US Inc. 5 SYRINGE in 1 CARTON (49281-575-15) / .5 mL in 1 SYRINGE July 18, 2023
49281-574 49281-574 Sanofi Vaccines US Inc. — July 18, 2023
49281-575 49281-575 Sanofi Vaccines US Inc. — July 18, 2023

Sources for this page

Every dataset that contributed a fact to this page.
Dataset Agency Used for
NDC Directory FDA Identity, ingredients, strengths, forms, routes, labelers, packages
Drugs@FDA FDA Application, sponsor, submissions, review documents, marketing status
Drug Labeling FDA / NLM Prescribing information reproduced above
FAERS FDA Adverse event report counts
Purple Book FDA Biologic licence classification

Generated September 25, 2026 · 10 sections on this page.