CompletedPhase 3

Study of a Single Intramuscular Dose of Nirsevimab in the Prevention of Hospitalizations Due to Respiratory Syncytial Virus (RSV) Infection in Healthy Term and Preterm Infants During the First Year of Life

France, Germany, United Kingdom8,057 participantsStarted 2022-08-08

Plain-language summary

The purpose of this study was to determine the efficacy and safety of a single intramuscular (IM) dose of nirsevimab, compared to no intervention, for the prevention of hospitalizations due to lower respiratory tract infection (LRTI) caused by confirmed RSV infection (henceforth referred to as RSV LRTI hospitalizations) in all infants under 12 months of age who were not eligible to receive palivizumab. The visit frequency was 1 in-person dosing/randomization visit, with monthly safety follow-up electronic contacts through the first 6 months post dosing/randomization for all participants. The study also included a 12-month (Day 366) follow-up telephone call. The D366 follow-up telephone call was the final follow-up telephone call for France, Germany and UK non-reconsented participants. The study included an 18-month (D546) and a 24-month (D731, final telephone call) follow-up telephone call for UK reconsented participants.

Who can participate

Age range

0 Days – 12 Months

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Born at ≥ 29 weeks gestational age and aged 0 to 12 months (calendar age), who entered their first RSV season on the day of inclusion in the study (D01) * Informed consent form was signed and dated by the parent(s) or other LAR(s) (and by an independent witness if required by local regulations) * Participant and parent/LAR were able to attend the scheduled visit and to comply with all study procedures Exclusion Criteria: * Participants were not eligible for the study if any of the following criteria are met: * Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months) * Active confirmed RSV infection at the time of dosing/randomization * Active LRTI at the time of dosing/randomization * Known systemic hypersensitivity to any of the study intervention components, or history of a life-threatening reaction to the study intervention used in the study or to a product containing any of the same substances * Laboratory confirmed thrombocytopenia, or known thrombocytopenia, as reported by the parent/LAR, contraindicating intramuscular injection * Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating intramuscular injection * Any condition that, in the opinion…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Number of Participants With Respiratory Syncytial Virus (RSV) Lower Respiratory Tract Infection (LRTI) Hospitalization Through the Respiratory Syncytial Virus Season

Timeframe: From dosing/randomization (Day 1) up to approximately 7 months

Trial details

NCT IDNCT05437510

SponsorSanofi Pasteur, a Sanofi Company

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2024-03-27

Results submitted2025-03-25

View on ClinicalTrials.gov More RSV Immunization trials