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AzTrials

RSV ImmunizationPhase 3NCT05437510

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

A Phase 3 study testing Nirsevimab in people with RSV Immunization and Healthy Volunteer, run by Sanofi Pasteur, a Sanofi Company at 240 sites in 3 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial 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… Read more about this study

Who is it for?
Ages 0 days to 12 monthsHealthy volunteers can take part
Conditions the study is for
RSV Immunization, Healthy Volunteer
What is being tested?
Nirsevimab
Type of treatment
Injection or infusion
Could I receive a placebo?
No, everyone receives an active treatment
How many people
8,057 participants
Where
240 sitesin 3 countries
Study dates
8 Aug 2022to 9 Apr 2025
Phase
Phase 3
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 0 days to 12 months
  • All sexes
  • Healthy volunteers accepted
  • Child

Who may be able to join

  • 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

Who cannot join

  • 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
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  • Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating intramuscular injection
  • Any condition that, in the opinion of the investigator, is at a stage where it might interfere with study conduct or completion
  • Moderate or severe acute illness/infection (according to investigator judgment) or febrile illness (temperature ≥ 38.0°C [≥ 100.4°F]) on the day of study intervention administration.
  • A prospective participant was not included in the study until the condition has resolved or the febrile event has subsided
  • Mother of the infant participant was administered an RSV vaccine during her pregnancy with the infant participant
  • Receipt of any monoclonal antibody by the infant participant
  • Receipt of immune globulins, blood or blood-derived products in the past 3 months by the infant participant
  • Participation at the time of study enrollment or planned participation during the present study period in another clinical study investigating a vaccine, drug, medical device, or medical procedure
  • Eligible to receive palivizumab at time of inclusion (as per local guidelines)
  • In an emergency setting or hospitalized involuntarily
  • Identified as a natural or adopted child of the Investigator or employee with direct involvement in the proposed study
  • The above information were not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.

Trial locations and contacts

240 sites in 3 countries.

240 sites in 3 countries

United Kingdom108 sites

  • Investigational Site Number: 8260007

    Amersham, HP7 0JD

  • Investigational Site Number: 8260096

    Ashford, N24 0LZ

  • Investigational Site Number: 8260053

    Banbury, OX16 9AD

  • Investigational Site Number: 8260057

    Barnet, EN5 3DJ

  • Investigational Site Number: 8260004

    Barnsley, S75 2EP

  • Investigational Site Number: 8260107

    Basildon, SS16 5NL

  • Investigational Site Number: 8260110

    Basingstoke, RG24 9NA

  • Investigational Site Number: 8260067

    Bath, BA1 3NG

  • Investigational Site 8260009

    Bath, BA2 3HT

  • Investigational Site Number: 8260100

    Bebington, CH63 9JP

  • Investigational Site Number: 8260073

    Belfast, BT7 2EB

  • Investigational Site Number: 8260095

    Bicester, OX26 6HR

  • Investigational Site Number: 8260029

    Blackburn, BB2 3HH

  • Investigational Site Number: 8260108

    Bollington, SK10 5JH

  • Investigational Site Number: 8260085

    Bolton, BL2 6NT

  • Investigational Site Number: 8260013

    Bradford, BD9 6RJ

  • Investigational Site Number: 8260112

    Brierley Hill, DY5 1RU

  • Investigational Site Number: 8260058

    Brighton, BN2 5BE

  • Investigational Site Number: 8260008

    Bristol, BS2 8EX

  • Investigational Site Number: 8260019

    Bristol, BS34 6BQ

  • Investigational Site 8260046

    Bristol, BS37 4AX

  • Investigational Site Number: 8260063

    Bury St Edmunds, IP33 2QZ

  • Investigational Site Number: 8260040

    Cardiff, CF14 4XN

  • Investigational Site Number: 8260062

    Cheltenham, GL53 7AN

  • Investigational Site Number: 8260066

    Chertsey, KT16 0PZ

  • Investigational Site Number: 8260061

    Chippenham, SN16 1GG

  • Investigational Site Number: 8260036

    Corby, NN17 2UR

  • Investigational Site Number: 8260054

    Cottingham, HU16 5JQ

  • Investigational Site Number: 8260035

    Darlington, DL3 6HX

  • Investigational Site Number: 8260037

    Darlington, DL3 6HX

  • Investigational Site Number: 8260041

    Darlington, DL3 8SQ

  • Investigational Site 8260064

    Dorchester, DT1 2JY

  • Investigational Site Number: 8260087

    Dundee, DD1 9SY

  • Investigational Site 8260018

    Exeter, EX2 5DW

  • Investigational Site Number: 8260020

    Gillingham, ME7 5NY

  • Investigational Site Number: 8260056

    Great Yarmouth, NR31 6LA

  • Investigational Site Number: 8260069

    Harrow, HA1 3UJ

  • Investigational Site Number: 8260109

    Highcliffe, BH23 5ET

  • Investigational Site Number: 8260101

    Ipswich, IP4 5PD

  • Investigational Site Number: 8260027

    Leicester, E1 5WW

  • Investigational Site Number: 8260091

    Leicester, LE1 6NB

  • Investigational Site Number: 8260074

    Leicester, LE9 7RT

  • Investigational Site Number: 8260088

    Liskeard, PL14 3XA

  • Investigational Site Number: 8260030

    Liverpool, L12 2AP

  • Investigational Site Number: 8260092

    Liverpool, L5 8XR

  • Investigational Site Number: 8260010

    London, E1 1BB

  • Investigational Site Number: 8260039

    London, E9 6SR

  • Investigational Site Number: 8260075

    London, NW1 2PG

  • Investigational Site Number: 8260011

    London, NW3 2QG

  • Investigational Site Number: 8260076

    London, NW3 2QU

  • Investigational Site Number: 8260077

    London, NW5 1TR

  • Investigational Site Number: 8260084

    London, SE1 7EH

  • Investigational Site Number: 8260079

    London, SE5 9RS

  • Investigational Site Number: 8260078

    London, SW10 9NH

  • Investigational Site Number: 8260001

    London, SW17 0RE

  • Investigational Site Number: 8260002

    London, W2 1NY

  • Investigational Site Number: 8260071

    Macclesfield, SK10 3BL

  • Investigational Site Number: 8260015

    Manchester, M13 9WL

  • Investigational Site Number: 8260097

    Margate, CT9 4AN

  • Investigational Site Number: 8260012

    Middlesbrough, TS4 3BW

  • Investigational Site Number: 8260042

    Milton Keynes, MK6 5LD

  • Investigational Site Number: 8260072

    Nantwich, CW5 5NX

  • Investigational Site Number: 8260044

    Newcastle upon Tyne, NE1 4LP

  • Investigational Site Number: 8260119

    Newport, PO30 5TG

  • Investigational Site Number: 8260045

    Newquay, TR7 1RU

  • Investigational Site Number: 8260024

    Norwich, NR4 7UY

  • Investigational Site 8260028

    Nottingham, NG7 2QW

  • Investigational Site 8260043

    Nottingham, NG9 6DX

  • Investigational Site Number: 8260022

    Oxford, OX3 9DU

  • Investigational Site Number: 8260003

    Oxford, OX4 1XB

  • Investigational Site Number: 8260080

    Penzance, TR18 3DX

  • Investigational Site Number: 8260093

    Peterborough, PE3 9GZ

  • Investigational Site Number: 8260081

    Plymouth, PL6 8DH

  • Investigational Site Number: 8260094

    Poole, BH15 2JB

  • Investigational Site 8260005

    Poole, BH16 5PW

  • Investigational Site Number: 8260065

    Portsmouth, PO6 3LY

  • Investigational Site Number: 8260106

    Prescot, L35 5DR

  • Investigational Site Number: 8260117

    Preston, PR2 9HT

  • Investigational Site Number: 8260016

    Reading, RG1 5AN

  • Investigational Site Number: 8260086

    Reading, RG8 7DP

  • Investigational Site Number: 8260103

    Redhill, RH1 5RH

  • Investigational Site Number: 8260105

    Redruth, TR15 3DU

  • Investigational Site 8260026

    Romsey, SO51 8EN

  • Investigational Site Number: 8260068

    Runcorn, WA7 2DA

  • Investigational Site Number: 8260059

    Salford, M6 8HD

  • Investigational Site Number: 8260111

    Salisbury, SP2 8BJ

  • Investigational Site Number: 8260014

    Sheffield, S10 2TH

  • Investigational Site 8260051

    Southampton, SO16 6YD

  • Investigational Site Number: 8260038

    Stevenage, SG1 4AB

  • Investigational Site Number: 8260034

    Stockport, SK2 7JE

  • Investigational Site Number: 8260025

    Stockton-on-Tees, TS19 8PE

  • Investigational Site Number: 8260052

    Sunderland, SR4 7TP

  • Investigational Site Number: 8260098

    Sutton in Ashfield, NG17 4JL

  • Investigational Site Number: 8260083

    Swanage, BH19 1HB

  • Investigational Site Number: 8260047

    Swindon, SN3 6BB

  • Investigational Site Number: 8260115

    Swinton, M27 0FX

  • Investigational Site Number: 8260102

    Tameside, OL6 9RW

  • Investigational Site Number: 8260032

    Taunton, TA1 5DA

  • Investigational Site Number: 8260031

    Torpoint, PL11 2TB

  • Investigational Site 8260082

    Wantage, OX12 9BN

  • Investigational Site Number: 8260017

    Waterlooville, PO8 8DL

  • Investigational Site Number: 8260104

    Winchester, SO22 5DG

  • Investigational Site Number: 8260021

    Winscombe, BS25 1AF

  • Investigational Site Number: 8260006

    Witney, OX28 6JS

  • Investigational Site Number: 8260060

    Witney, OX29 4QB

  • Investigational Site Number: 8260050

    Yeovil, BA21 4AT

  • Investigational Site Number: 8260116

    York, YO24 1LW

  • Investigational Site 8260023

    York, YO31 8HE

Other trials in United Kingdom

France66 sites

  • Investigational Site 2500041

    Aix-en-Provence, 13100

  • Investigational Site 2500002

    Amiens, 80054

  • Investigational Site Number: 2500014

    Bordeaux, 33076

  • Investigational Site 2500007

    Brest, 29200

  • Investigational Site Number: 2500038

    Brest, 29200

  • Investigational Site Number: 2500045

    Brest, 29200

  • Investigational Site Number: 2500019

    Bron, 69677

  • Investigational Site Number: 2500043

    Brumath, 67170

  • Investigational Site Number: 2500001

    Caen, 14033

  • Investigational Site Number: 2500032

    Chambéry, 73000

  • Investigational Site Number: 2500057

    Clamart, 92140

  • Investigational Site Number: 2500065

    Clamart, 92140

  • Investigational Site Number: 2500029

    Combs-la-Ville, 77380

  • Investigational Site Number: 2500013

    Corbeil-Essonnes, 91100

  • Investigational Site Number: 2500054

    Creil, 60100

  • Investigational Site Number: 2500006

    Créteil, 94010

  • Investigational Site Number: 2500039

    Créteil, 94010

  • Investigational Site Number: 2500023

    Dijon, 21000

  • Investigational Site Number: 2500069

    Draguignan, 83300

  • Investigational Site 2500008

    Essey-lès-Nancy, 54270

  • Investigational Site 2500030

    Étampes, 91150

  • Investigational Site Number: 2500058

    Frouard, 54390

  • Investigational Site Number: 2500064

    Grasse, 06135

  • Investigational Site Number: 2500004

    Grenoble, 38043

  • Investigational Site Number: 2500027

    Héry-sur-Alby, 74540

  • Investigational Site Number: 2500060

    Huningue, 68330

  • Investigational Site 2500059

    La Garenne-Colombes, 92250

  • Investigational Site Number: 2500071

    La Teste-de-Buch, 33260

  • Investigational Site Number: 2500034

    Le Kremlin-Bicêtre, 94270

  • Investigational Site Number: 2500072

    Libourne, 33500

  • Investigational Site 2500046

    Lille, 59000

  • Investigational Site 2500005

    Lille, 59037

  • Investigational Site Number: 2500012

    Limoges, 87042

  • Investigational Site Number: 2500037

    Longjumeau, 91160

  • Investigational Site 2500021

    Maromme, 76150

  • Investigational Site Number: 2500003

    Marseille, 13015

  • Investigational Site Number: 2500073

    Marseille, 13385

  • Investigational Site Number: 2500068

    Mont-de-Marsan, 40000

  • Investigational Site Number: 2500066

    Mont-Saint-Aignan, 76130

  • Investigational Site Number: 2500067

    Montpellier, 34295

  • Investigational Site Number: 2500077

    Morlaix, 29600

  • Investigational Site Number: 2500047

    Nantes, 44093

  • Investigational Site Number: 2500055

    Nice, 06200

  • Investigational Site Number: 2500009

    Nice, 06300

  • Investigational Site Number: 2500040

    Nogent-sur-Marne, 94130

  • Investigational Site Number: 2500022

    Orléans, 45000

  • Investigational Site Number: 2500050

    Orléans, 45067

  • Investigational Site Number: 2500024

    Paris, 75011

  • Investigational Site Number: 2500010

    Paris, 75012

  • Investigational Site Number: 2500075

    Paris, 75012

  • Investigational Site Number: 2500051

    Paris, 75016

  • Investigational Site Number:

    Pau, 64000

  • Investigational Site Number: 2500018

    Poissy, 78300

  • Investigational Site Number: 2500026

    Puteaux, 92800

  • Investigational Site Number: 2500042

    Rouen, 76000

  • Investigational Site Number: 2500078

    Saint-Doulchard, 18230

  • Investigational Site Number: 2500074

    Saint-Julien-en-Genevois, 74160

  • Investigational Site Number: 2500044

    Saint-Maur-des-Fossés, 94100

  • Investigational Site 2500020

    Saint-Sébastien-sur-Loire, 44230

  • Investigational Site Number: 2500052

    Saverne, 67700

  • Investigational Site Number: 2500015

    Toulouse, 31059

  • Investigational Site Number: 2500035

    Tours, 37000

  • Investigational Site Number: 2500049

    Vendenheim, 67550

  • Investigational Site Number: 2500011

    Villeneuve-lès-Avignon, 30400

  • Investigational Site Number: 2500063

    Villeneuve-Saint-Georges, 94195

  • Investigational Site 2500028

    Vincennes, 94300

Other trials in France

Germany66 sites

  • Investigational Site Number: 2760036

    Augsburg, 86154

  • Investigational Site Number: 2760017

    Bad Wildungen, 34537

  • Investigational Site Number: 2760099

    Berlin, 10551

  • Investigational Site Number: 2760076

    Berlin, 13353

  • Investigational Site Number: 2760056

    Berlin, 13589

  • Investigational Site Number: 2760050

    Bielefeld, 33617

  • Investigational Site Number: 2760064

    Bocholt, 46397

  • Investigational Site Number: 2760098

    Bochum, 44791

  • Investigational Site Number: 2760040

    Bonn, 53127

  • Investigational Site Number: 2760025

    Bramsche, 49565

  • Investigational Site Number: 2760018

    Braunschweig, 38118

  • Investigational Site Number: 2760051

    Detmold, 32756

  • Investigational Site Number: 2760085

    Dortmund, 44137

  • Investigational Site Number: 2760059

    Düsseldorf, 40217

  • Investigational Site Number: 2760101

    Düsseldorf, 40589

  • Investigational Site Number: 2760081

    Eckental, 90542

  • Investigational Site Number: 2760045

    Erfurt, 99086

  • Investigational Site Number: 2760047

    Forchheim, 91301

  • Investigational Site Number: 2760030

    Frankfurt (Oder), 15236

  • Investigational Site Number: 2760015

    Freiburg I. Breisgau, 79106

  • Investigational Site Number: 2760079

    Gera, 07548

  • Investigational Site Number: 2760005

    Gilching, 82205

  • Investigational Site Number: 2760016

    Göttingen, 37075

  • Investigational Site Number: 2760060

    Göttingen, 37075

  • Investigational Site Number: 2760033

    Hamburg, 20251

  • Investigational Site Number: 2760057

    Hamburg, 20357

  • Investigational Site Number: 2760096

    Hamburg, 22415

  • Investigational Site Number: 2760032

    Hamm, 59063

  • Investigational Site Number: 2760007

    Hanover, 30625

  • Investigational Site Number: 2760049

    Heidelberg, 69120

  • Investigational Site Number: 2760008

    Herford, 32049

  • Investigational Site 2760010

    Hürth, 50354

  • Investigational Site Number: 2760091

    Hürth, 50354

  • Investigational Site Number: 2760035

    Itzehoe, 25524

  • Investigational Site Number: 2760095

    Kassel, 34119

  • Investigational Site Number: 2760084

    Kirchen, 57548

  • Investigational Site Number: 2760065

    Krefeld, 47799

  • Investigational Site Number: 2760020

    Leipzig, 04179

  • Investigational Site Number: 2760013

    Leipzig, 4103

  • Investigational Site 2760006

    Mainz, 55116

  • Investigational Site Number: 2760086

    Mainz, 55131

  • Investigational Site Number: 2760014

    Mannheim, 68161

  • Investigational Site Number: 2760023

    Mönchengladbach, 41236

  • Investigational Site Number: 2760054

    Mönchengladbach, 41236

  • Investigational Site Number: 2760094

    München, 80638

  • Investigational Site Number: 2760034

    München, 81369

  • Investigational Site Number: 2760038

    München, 81369

  • Investigational Site Number: 2760019

    München, 81375

  • Investigational Site Number: 2760046

    München, 81377

  • Investigational Site Number: 2760061

    München, 81925

  • Investigational Site Number: 2760083

    Münster, 48149

  • Investigational Site Number: 2760027

    Neuss, 41469

  • Investigational Site Number: 2760004

    Niedernhausen, 65527

  • Investigational Site Number: 2760071

    Passau, 94032

  • Investigational Site Number: 2760001

    Regensburg, 93053

  • Investigational Site Number: 2760003

    Rosenheim, 83026

  • Investigational Site Number: 2760062

    Rüsselsheim A. Main, 65428

  • Investigational Site Number: 2760092

    Saarbrücken, 66119

  • Investigational Site 2760029

    Schönau, 83471

  • Investigational Site Number: 2760044

    Schweigen, 76889

  • Investigational Site Number: 2760069

    Suhl, 98527

  • Investigational Site Number: 2760067

    Tuttlingen, 78532

  • Investigational Site Number: 2760043

    Weiden, 92637

  • Investigational Site Number: 2760002

    Wesel, 46483

  • Investigational Site Number: 2760093

    Wolfsburg, 38440

  • Investigational Site Number: 2760028

    Wolfsburg, 38448

Other trials in Germany

About this study

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

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.

Read the detailed description

12 months post-dosing/randomization for France, Germany and UK non-reconsented participants, 24 months post-dosing/randomization for UK reconsented participants. D01 was the day of randomization (both study groups) and immunization (nirsevimab group).

Being tested
Nirsevimab

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • NirsevimabBiological

    Pharmaceutical Form: Solution for Injection Route of Administration: Intramuscular

Study groups in NCT05437510
Study groupRoleWhat they receive
NirsevimabExperimental1 intramuscular injection at Day 01
Receives: Biological: Nirsevimab
No preventive intervention for RSVNo interventionNo intervention

What is being measured

The primary outcome is the main question the study is designed to answer.

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

    LRTI included the following common symptoms: clinical finding of rhonchi, rales, crackles, or wheeze; increased respiratory rate at rest (age: <2 months, ≥60 breaths per minute (/min); 2 to 6 months, ≥50 breaths/min; >6 months, ≥40 breaths/min), and hypoxemia (in room air: oxygen saturation <95%). Hospitalization was defined as the decision to admit to in-patient care by the treating physician. RSV season was the period of increased RSV infection.

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

Secondary outcomes (17)

  1. Number of Participants With Very Severe Respiratory Syncytial Virus Lower Respiratory Tract Infection Through the Respiratory Syncytial Virus Season

    LRTI included the following common symptoms: clinical finding of rhonchi, rales, crackles, or wheeze; increased respiratory rate at rest (age: <2 months, ≥60 breaths/min; 2 to 6 months, ≥50 breaths/min; >6 months, ≥40 breaths/min), and hypoxemia (in room air: oxygen saturation <95%). Very severe RSV LRTI was defined as RSV LRTI hospitalization with oxygen saturation <90% (at any time during hospitalization) and oxygen supplementation. Hospitalization was defined as the decision to admit to in-patient care by the treating physician. RSV season was the period of increased RSV infection.

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

  2. Number of Participants With Respiratory Syncytial Virus Lower Respiratory Tract Infection Hospitalization Through the Respiratory Syncytial Virus Season in Each Country

    LRTI included the following common symptoms: clinical finding of rhonchi, rales, crackles, or wheeze; increased respiratory rate at rest (age: <2 months, ≥60 breaths/min; 2 to 6 months, ≥50 breaths/min; >6 months, ≥40 breaths/min), and hypoxemia (in room air: oxygen saturation <95%). Hospitalization was defined as the decision to admit to in-patient care by the treating physician. RSV season was the period of increased RSV infection. Number of participants with RSV LRTI hospitalization through the RSV season in France, UK, and Germany is presented.

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

  3. Number of Participants With Hospitalization for All-Cause Lower Respiratory Tract Infection Through the Respiratory Syncytial Virus Season

    LRTI included the following common symptoms: clinical finding of rhonchi, rales, crackles, or wheeze; increased respiratory rate at rest (age: <2 months, ≥60 breaths/min; 2 to 6 months, ≥50 breaths/min; >6 months, ≥40 breaths/min), and hypoxemia (in room air: oxygen saturation <95%). Hospitalization was defined as the decision to admit to in-patient care by the treating physician. RSV season was the period of increased RSV infection. Number of participants with hospitalization for all-cause LRTI through the RSV season in France, UK, Germany, and overall is presented.

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

  4. Number of Participants With Respiratory Syncytial Virus Lower Respiratory Tract Infection Hospitalization Through 151 Days Post-dosing/Randomization

    LRTI included the following common symptoms: clinical finding of rhonchi, rales, crackles, or wheeze; increased respiratory rate at rest (age: <2 months, ≥60 breaths/min; 2 to 6 months, ≥50 breaths/min; >6 months, ≥40 breaths/min), and hypoxemia (in room air: oxygen saturation <95%). Hospitalization was defined as the decision to admit to in-patient care by the treating physician. Number of participants with RSV LRTI hospitalization through 151 days post-dosing/randomization in France, UK, Germany, and overall is presented.

    Measured: From dosing/randomization (Day 1) to Day 151

  5. Number of Participants With Very Severe Respiratory Syncytial Virus Lower Respiratory Tract Infection Through 151 Days Post-dosing/Randomization

    LRTI included the following common symptoms: clinical finding of rhonchi, rales, crackles, or wheeze; increased respiratory rate at rest (age: <2 months, ≥60 breaths/min; 2 to 6 months, ≥50 breaths/min; >6 months, ≥40 breaths/min), and hypoxemia (in room air: oxygen saturation <95%). Very severe RSV LRTI was defined as RSV LRTI hospitalization with oxygen saturation <90% (at any time during hospitalization) and oxygen supplementation. Hospitalization was defined as the decision to admit to in-patient care by the treating physician. Number of participants with very severe RSV LRTI through 151 days post-dosing/randomization in France, UK, Germany, and overall is presented.

    Measured: From dosing/randomization (Day 1) to Day 151

  6. Number of Participants With Hospitalization for All-Cause Lower Respiratory Tract Infection Through 151 Days Post-dosing/Randomization

    LRTI included the following common symptoms: clinical finding of rhonchi, rales, crackles, or wheeze; increased respiratory rate at rest (age: <2 months, ≥60 breaths/min; 2 to 6 months, ≥50 breaths/min; >6 months, ≥40 breaths/min), and hypoxemia (in room air: oxygen saturation <95%). Hospitalization was defined as the decision to admit to in-patient care by the treating physician. Number of participants with hospitalization for all-cause LRTI through 151 days post-dosing/randomization in France, UK, Germany, and overall is presented.

    Measured: From dosing/randomization (Day 1) to Day 151

  7. Number of Participants With Immediate Treatment-Emergent Adverse Events (TEAEs)

    An adverse event (AE) was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. TEAEs were either events with the start date and time posterior to the start of the treatment period and up to the end of the treatment period or events with the start date and time prior to the start of the treatment period, whose severity was greater than 1 or missing and stop date is missing or not before the treatment period. Immediate events were recorded to capture medically relevant AEs which occurred within the first 30 minutes after immunization.

    Measured: Up to 30 minutes post-dosing/randomization on Day 1

  8. Number of Participants With Non-Serious Treatment-Emergent Adverse Events

    An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. TEAEs were either events with the start date and time posterior to the start of the treatment period and up to the end of the treatment period or events with the start date and time prior to the start of the treatment period, whose severity was greater than 1 or missing and stop date was missing or not before the treatment period.

    Measured: From dosing/randomization (Day 1) to Day 31

  9. Number of Participants With Treatment-Emergent Serious Adverse Events (SAEs), Treatment-Emergent Adverse Events of Special Interest (AESIs) and Treatment-Emergent Medically Attended Adverse Events (MAAEs)

    AE: untoward medical occurrence in clinical study participant, temporally associated with use of study intervention, whether or not related to it. TEAEs: events with start date/time posterior to start of treatment period(TP) and up to end of TP, or events with start date/time prior to start of TP, whose severity was>1/missing; stop date was missing/not before TP. SAE: AE at any dose resulting in death, persistent or significant disability/incapacity, required inpatient hospitalization/prolongation of existing hospitalization, was life-threatening or congenital anomaly/birth defect or medically important event. MAAE: new onset/worsening of condition that prompted participant or participant's parent/legally acceptable representative to seek unplanned medical advice at physician's office/Emergency Department. AESI: scientific, medical concern specific to Sponsor's study intervention/program for which ongoing monitoring and rapid communication by investigator to Sponsor was appropriate.

    Measured: From dosing/randomization (Day 1) to Day 366

  10. Number of Participants With Treatment-Related Serious Adverse Event (for United Kingdom Reconsented Participants)

    An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. TEAEs were either events with the start date and time posterior to the start of the treatment period and up to the end of the treatment period or events with the start date and time prior to the start of the treatment period, whose severity was greater than 1 or missing and stop date is missing or not before the treatment period. SAE: AE at any dose resulting in death, persistent or significant disability/incapacity, required inpatient hospitalization/prolongation of existing hospitalization, was life-threatening or congenital anomaly/birth defect or medically important event. A treatment-related TEAE was a TEAE considered by the investigator as related or with unknown/missing relationship to treatment for participants who received nirsevimab on Day 1.

    Measured: From Day 366 to Day 731

  11. Number of Participants With Respiratory Syncytial Virus Lower Respiratory Tract Infection Hospitalization Through 181 Days Post-dosing/Randomization

    LRTI included the following common symptoms: clinical finding of rhonchi, rales, crackles, or wheeze; increased respiratory rate at rest (age: <2 months, ≥60 breaths/min; 2 to 6 months, ≥50 breaths/min; >6 months, ≥40 breaths/min), and hypoxemia (in room air: oxygen saturation <95%). Hospitalization was defined as the decision to admit to in-patient care by the treating physician. Number of participants with RSV LRTI hospitalization through 181 days post-dosing/randomization in France, UK, Germany, and overall is presented.

    Measured: From dosing/randomization (Day 1) to Day 181

  12. Number of Participants With Hospitalization for All-Cause Lower Respiratory Tract Infection Through 181 Days Post-dosing/Randomization

    LRTI included the following common symptoms: clinical finding of rhonchi, rales, crackles, or wheeze; increased respiratory rate at rest (age: <2 months, ≥60 breaths/min; 2 to 6 months, ≥50 breaths/min; >6 months, ≥40 breaths/min), and hypoxemia (in room air: oxygen saturation <95%). Hospitalization was defined as the decision to admit to in-patient care by the treating physician. Number of participants with hospitalization for all-cause LRTI through 181 days post-dosing/randomization in France, UK, Germany, and overall is presented.

    Measured: From dosing/randomization (Day 1) to Day 181

  13. Number of Participants With Respiratory Syncytial Virus Lower Respiratory Tract Infection Hospitalization From Days 181 to 366 Post-dosing/Randomization

    LRTI included the following common symptoms: clinical finding of rhonchi, rales, crackles, or wheeze; increased respiratory rate at rest (age: <2 months, ≥60 breaths/min; 2 to 6 months, ≥50 breaths/min; >6 months, ≥40 breaths/min), and hypoxemia (in room air: oxygen saturation <95%). Hospitalization was defined as the decision to admit to in-patient care by the treating physician. Number of participants with RSV LRTI hospitalization from Days 181 to 366 post-dosing/randomization (with no RSV LRTI hospitalizations before Day 181) in France, UK, Germany, and overall is presented.

    Measured: From Day 181 to Day 366

  14. Number of Participants With Hospitalization for All-Cause Lower Respiratory Tract Infection From Days 181 to 366 Post-dosing/Randomization

    LRTI included the following common symptoms: clinical finding of rhonchi, rales, crackles, or wheeze; increased respiratory rate at rest (age: <2 months, ≥60 breaths/min; 2 to 6 months, ≥50 breaths/min; >6 months, ≥40 breaths/min), and hypoxemia (in room air: oxygen saturation <95%). Hospitalization was defined as the decision to admit to in-patient care by the treating physician. Number of participants with hospitalization for all-cause LRTI from Days 181 to 366 post-dosing/randomization (with no hospitalizations for all-cause LRTI before Day 181) is presented.

    Measured: From Day 181 to Day 366

  15. Number of Participants With Respiratory Syncytial Virus Lower Respiratory Tract Infection Hospitalization From Days 366 to 731 Post-dosing/Randomization (for United Kingdom Reconsented Participants)

    LRTI included the following common symptoms: clinical finding of rhonchi, rales, crackles, or wheeze; increased respiratory rate at rest (age: <2 months, ≥60 breaths/min; 2 to 6 months, ≥50 breaths/min; >6 months, ≥40 breaths/min), and hypoxemia (in room air: oxygen saturation <95%). Hospitalization was defined as the decision to admit to in-patient care by the treating physician. Number of participants with RSV LRTI hospitalization from Days 366 to 731 post-dosing/randomization (with no RSV LRTI hospitalizations before Day 366) in UK reconsented participants is presented.

    Measured: From Day 366 to Day 731

  16. Number of Participants With Hospitalization for All-Cause Lower Respiratory Tract Infection From Days 366 to 731 Post-dosing/Randomization (for United Kingdom Reconsented Participants)

    LRTI included the following common symptoms: clinical finding of rhonchi, rales, crackles, or wheeze; increased respiratory rate at rest (age: <2 months, ≥60 breaths/min; 2 to 6 months, ≥50 breaths/min; >6 months, ≥40 breaths/min), and hypoxemia (in room air: oxygen saturation <95%). Hospitalization was defined as the decision to admit to in-patient care by the treating physician. Number of participants with hospitalization for all-cause LRTI from Days 366 to 731 post-dosing/randomization (with no hospitalizations for all-cause LRTI before Day 366) in UK reconsented participants is presented.

    Measured: From Day 366 to Day 731

  17. Number of Participants With Recurrent Wheeze (for United Kingdom Reconsented Participants)

    Wheeze was defined as a physician-diagnosed wheeze or asthma or related ear, nose and throat (ENT)/respiratory symptoms at an office visit or an illness for which the child was prescribed medication to treat an ENT/respiratory condition. Recurrent wheeze event was defined as 2 or more protocol-defined wheeze episodes throughout follow-up period.

    Measured: From dosing/randomization (Day 1) to Day 731

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted29 Jun 2022
  2. Study start8 Aug 2022
  3. Primary completion27 Mar 2024
  4. Study completion9 Apr 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 3
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Model description
1 in-person randomization visit, with monthly safety and efficacy follow-up conducted through electronic contact through the first 6 months post-dosing/randomization. The study also included a 12-month (D366) 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.
Masking
None (open label)
Enrolment
8,057 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05437510
Sponsor's protocol ID
VAS00006
Other IDs
U1111-1272-2514, 2022-000099-20
Status last verified
Sep 2025
First submitted
24 Jun 2022
Last updated
9 Oct 2025
Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org

Publications

  • Munro APS, Drysdale SB, Cathie K, Flamein F, Knuf M, Collins AM, Hill HC, Kaiser F, Cohen R, Pinquier D, Vassilouthis NC, Carreno M, Moreau C, Bourron P, Marcelon L, Mari K, Roberts M, Tissieres P, Royal S, Faust SN; HARMONIE Study Group. 180-day efficacy of nirsevimab against hospitalisation for respiratory syncytial virus lower respiratory tract infections in infants (HARMONIE): a randomised, controlled, phase 3b trial. Lancet Child Adolesc Health. 2025 Jun;9(6):404-412. doi: 10.1016/S2352-4642(25)00102-6.

    PubMed 40379431

  • Drysdale SB, Cathie K, Flamein F, Knuf M, Collins AM, Hill HC, Kaiser F, Cohen R, Pinquier D, Felter CT, Vassilouthis NC, Jin J, Bangert M, Mari K, Nteene R, Wague S, Roberts M, Tissieres P, Royal S, Faust SN; HARMONIE Study Group. Nirsevimab for Prevention of Hospitalizations Due to RSV in Infants. N Engl J Med. 2023 Dec 28;389(26):2425-2435. doi: 10.1056/NEJMoa2309189.

    PubMed 38157500

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Nirsevimab in people with RSV Immunization and Healthy Volunteer, run by Sanofi Pasteur, a Sanofi Company at 240 sites in 3 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 18 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 9 Oct 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 240 sites in United Kingdom, France, Germany. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 11 Apr 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Number of Participants With Respiratory Syncytial Virus (RSV) Lower Respiratory Tract Infection (LRTI) Hospitalization Through the Respiratory Syncytial Virus Season (time frame: From dosing/randomization (Day 1) up to approximately 7 months). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05437510, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Oct 2025.

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