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Drug

Nirsevimab

Approved medicine
ResearchOngoing clinical research

Also known as Beyfortus.

RxNorm2642401UNIIVRN8S9CW5V
6
Active clinical trials
1
Regulatory events
Latest activity
beta

Recent clinical, regulatory, research and industry developments relating to this drug.

A Phase 4, Open-label, Single-arm Clinical Study to Describe Safety and Efficacy Outcomes Associated With the Use of Nirsevimab in Neonates and Infants Born During or Entering Their First Respiratory Syncytial Virus (RSV) Season and in Children up to 24 Months of Age Who Remain Vulnerable to Severe RSV Disease Through Their Second RSV Season

Clinical trial2026-06-30Primary completion · ClinicalTrials.gov

Prevention of RSV Infection in Infants by Administering Nirsevimab to Infants, With or Without Maternal RSV Vaccination: a Randomised Controlled Trial in France as Part of the Pregnancy and Infant PrEparedness pLatform IN Europe - PIPELINE

Clinical trial2026-05-27Results expected Q2 2029 · ClinicalTrials.gov

Passive Immunisation With RSV-specific Monoclonal Antibody (RSV-SMA) to Prevent RSV Respiratory Infections Among Aboriginal and Torres Strait Islander Children in the Northern Territory: a Pragmatic Randomised Controlled Trial.

Clinical trial2026-05-11Results expected Q3 2030 · ClinicalTrials.gov

A Phase III Single-Arm Open-Label Study to Evaluate the Safety PK ADA and Anti RSV nAb Following Administration of 2 Doses of Nirsevimab Given 5 to 6 Months Apart in Infants With CHD, CLD, Immunocompromise, Down Syndrome, or Born Pre-Term in Japan

Clinical trial2026-04-16Results posted · ClinicalTrials.gov

A Randomized, Double-blind, Placebo/Positive Control, Dose-finding Phase Ib/IIa Clinical Trial Evaluating the Safety, Tolerability, and Pharmacokinetics of SIBP-A16 Injection in Premature Infants and Full-term Infants

Clinical trial2026-01-23Results expected Q1 2027 · ClinicalTrials.gov

A Randomized, Double-blind, Placebo/Positive Control Phase Ia Clinical Trial Evaluating the Safety, Tolerability, and Pharmacokinetics of SIBP-A16 Injection in Healthy Adults

Clinical trial2025-11-25Results expected Q2 2027 · ClinicalTrials.gov

A Phase 3, Randomized, Double-blind, Placebo-controlled Study to Evaluate the Safety and Efficacy of Nirsevimab, a Monoclonal Antibody With Extended Half-life Against Respiratory Syncytial Virus, in Healthy Preterm and Term Infants in China

Clinical trial2025-11-24Completed · ClinicalTrials.gov

A Phase IIIb Randomized Open-label Study of Nirsevimab (Versus no Intervention) in Preventing Hospitalizations Due to Respiratory Syncytial Virus in Infants (HARMONIE)

Clinical trial2025-10-09Results posted · ClinicalTrials.gov

PIPELINE-RSV International Trial. Pregnancy and Infant PrEparedness pLatform IN Europe (PIPELINE)- RSV International Immunisation Adaptive Platform Trial.

Clinical trial2025-06-27Results expected Q4 2028 · ClinicalTrials.gov

A Phase 2, Open-label, Uncontrolled, Single-dose Study to Evaluate the Safety and Tolerability, Pharmacokinetics, and Occurrence of Antidrug Antibody for Nirsevimab in Immunocompromised Children ≤ 24 Months of Age

Clinical trial2023-11-15Results posted · ClinicalTrials.gov

A Phase 1, Randomized, Double-blind, Placebo-controlled Study to Evaluate the Pharmacokinetics, Safety, and Tolerability of Nirsevimab in Healthy Chinese Adults

Clinical trial2023-11-02Results posted · ClinicalTrials.gov

Approval: Beyfortus (EMA)

Regulatory2022-10-31EMA

Profile

Identifiers & mechanism

Canonical identifiers, marketed brand names and mechanism, resolved across RxNorm, ChEMBL and ATC.

Canonical name
Nirsevimab
Aliases & brands
Beyfortus
RxNorm CUI
2642401
UNII
VRN8S9CW5V
Regulatory jurisdictions
ema

Regulatory timeline

1 event

The complete regulatory record, grouped by authority — approvals, safety advisories and label changes. Each authority shows its most recent events; expand one to read its full history.

Earliest approval
2022-10-31
Latest approval
2022-10-31
Authorities
EMA
Total events
1
emaEuropean Medicines Agency· 1 event
2022-10-31Approval
Approval: Beyfortus (EMA)
Indication: Beyfortus is indicated for the prevention of Respiratory Syncytial Virus (RSV) lower respiratory tract disease in:i.        Neonates and infants… Show full indication

Beyfortus is indicated for the prevention of Respiratory Syncytial Virus (RSV) lower respiratory tract disease in:i.        Neonates and infants during their first RSV season.ii.        Children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season (see section 5.1).Beyfortus should be used in accordance with official recommendations. Beyfortus is indicated for the prevention of Respiratory Syncytial Virus (RSV) lower respiratory tract disease in:i.          Neonates and infants during their first RSV season.ii.         Children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season (see section 5.1).Beyfortus should be used in accordance with official recommendations.

Evidence ↗

Contains information from the European Medicines Agency (European Medicines Agency), © EMA, reused under CC BY 4.0.

Clinical trials

11 trials

The current development programme across all trial phases — status mix, phase distribution and the late-stage studies shaping the evidence base.

Development programme
CLINICALTRIALS.GOV · LIVE REGISTRY
11
registered trials across all phases
LATEST COMPLETION 2025
6
Active studies
5
Recruiting
7
Late-stage (III+)
5
Completed
PHASE DISTRIBUTIONn = 11
Early Phase 11Phase 11Phase 1 / 21Phase 21Phase 35Phase 42

Late-stage studies

Phase III+ trials still open or recently active — where late-stage evidence is being generated.

Passive Immunisation With RSV-specific Monoclonal Antibody (RSV-SMA) to Prevent RSV Respiratory Infections Among Aboriginal and Torres Strait Islander Children in the Northern Territory: a Pragmatic Randomised Controlled Trial.

Not yet recruitingPH IVKey trialMenzies School of Health Researchn=1,0002030

A Phase 4, Open-label, Single-arm Clinical Study to Describe Safety and Efficacy Outcomes Associated With the Use of Nirsevimab in Neonates and Infants Born During or Entering Their First Respiratory Syncytial Virus (RSV) Season and in Children up to 24 Months of Age Who Remain Vulnerable to Severe RSV Disease Through Their Second RSV Season

Active, not recruitingPH IVSanofin=1102026

Prevention of RSV Infection in Infants by Administering Nirsevimab to Infants, With or Without Maternal RSV Vaccination: a Randomised Controlled Trial in France as Part of the Pregnancy and Infant PrEparedness pLatform IN Europe - PIPELINE

RecruitingPH IIIKey trialCentre Hospitalier Annecy Genevoisn=1,0002029

PIPELINE-RSV International Trial. Pregnancy and Infant PrEparedness pLatform IN Europe (PIPELINE)- RSV International Immunisation Adaptive Platform Trial.

Not yet recruitingPH IIIKey trialPENTA Foundationn=1,5002028

A Phase 3, Randomized, Double-blind, Placebo-controlled Study to Evaluate the Safety and Efficacy of Nirsevimab, a Monoclonal Antibody With Extended Half-life Against Respiratory Syncytial Virus, in Healthy Preterm and Term Infants in China

CompletedPH IIIAstraZenecan=8002025

Recent completions

Trials that read out recently, adding to the completed evidence base.

A Phase 3, Randomized, Double-blind, Placebo-controlled Study to Evaluate the Safety and Efficacy of Nirsevimab, a Monoclonal Antibody With Extended Half-life Against Respiratory Syncytial Virus, in Healthy Preterm and Term Infants in China

CompletedPH IIIAstraZenecan=8002025

A Phase III Single-Arm Open-Label Study to Evaluate the Safety PK ADA and Anti RSV nAb Following Administration of 2 Doses of Nirsevimab Given 5 to 6 Months Apart in Infants With CHD, CLD, Immunocompromise, Down Syndrome, or Born Pre-Term in Japan

CompletedPH IIIAstraZenecan=332025

A Phase IIIb Randomized Open-label Study of Nirsevimab (Versus no Intervention) in Preventing Hospitalizations Due to Respiratory Syncytial Virus in Infants (HARMONIE)

CompletedPH IIIKey trialSanofi Pasteur, a Sanofi Companyn=8,0572025

A Phase 2, Open-label, Uncontrolled, Single-dose Study to Evaluate the Safety and Tolerability, Pharmacokinetics, and Occurrence of Antidrug Antibody for Nirsevimab in Immunocompromised Children ≤ 24 Months of Age

CompletedPH IIAstraZenecan=1002023

A Phase 1, Randomized, Double-blind, Placebo-controlled Study to Evaluate the Pharmacokinetics, Safety, and Tolerability of Nirsevimab in Healthy Chinese Adults

CompletedPH IAstraZenecan=242021
References & data sources
  • RxNorm (U.S. National Library of Medicine) — drug identity
  • ClinicalTrials.gov — clinical trials
  • Regulatory event sources are credited in the Regulatory Timeline above.