AzTrials
AzTrials

RSV InfectionPhase 3SMARTNCT04938830

Clesrovimab (MK-1654) in Infants and Children at Increased Risk for Severe Respiratory Syncytial Virus (RSV) Disease (MK-1654-007)

A Phase 3 study testing Clesrovimab and Palivizumab in people with RSV Infection, run by Merck Sharp & Dohme LLC at 146 sites in 27 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

This study aims to evaluate the safety and tolerability of clesrovimab compared to palivizumab as assessed by the proportion of participants experiencing adverse events (AEs). Read more about this study

Who is it for?
Ages Up to 1 year
Conditions the study is for
RSV Infection
What is being tested?
Clesrovimab and Palivizumab
Type of treatment
Injection or infusion
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
1,003 participants
Where
146 sitesin 27 countries
Study dates
30 Nov 2021to 1 Aug 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 Up to 1 year
  • All sexes
  • No healthy volunteers
  • Child

Who may be able to join

  • Participants at increased risk for severe RSV infection recommended to receive palivizumab in accordance with national or local guidelines or professional society recommendations and meet defined criteria for the Early or Moderate Pre-term Group or the chronic lung disease (CLD)/congenital heart disease (CHD) Group.
  • Is available to complete the follow-up period.
  • Additional inclusion criteria for participation in RSV Season 2:
  • RSV Season 2 participants enrolled in the CLD/CHD Group in RSV Season 1. Participants with CHD must also have the following:
  • Hemodynamically significant CHD at the beginning of RSV Season 2, or
  • If the participant has had surgically repaired hemodynamically significant CHD that did not include extracorporeal membrane oxygenation (ECMO) or cardiopulmonary bypass: 1) continues to require medications to manage CHD, or 2) any additional medical intervention related to their CHD.
Show all 11Show fewer
  • RSV Season 2 participants enrolled in the Early or Moderate Pre-term Group in RSV Season 1, with the following:
  • Neuromuscular disease or congenital pulmonary anomaly that impairs the ability to clear secretions from the upper airway because of ineffective cough
  • Down Syndrome (trisomy of chromosome 21)
  • Cystic fibrosis with nutritional compromise
  • Native Americans and Alaskan Indians or other indigenous populations at high risk for severe RSV disease

Who cannot join

  • Requires mechanical ventilation at time of enrollment.
  • Has a life expectancy <6 months.
  • Has known hepatic or renal dysfunction, or chronic seizure disorder.
  • Is hospitalized at the time of randomization unless discharge is expected within 7 days after randomization.
  • Has severe immunodeficiency or is severely immunocompromised.
  • Has known hypersensitivity to any component of clesrovimab or palivizumab.
  • Additional exclusion criteria for participation in RSV Season 2:
  • Had 1) ECMO or 2) surgical intervention during the RSV season for CHD and required cardiopulmonary bypass during the procedure in RSV Season 1.

Trial locations and contacts

146 sites in 27 countries.

146 sites in 27 countries

United States29 sites
  • Morehouse School Of Medicine ( Site 0049)

    Atlanta, Georgia, 30310

  • Children's Hospital Colorado ( Site 0011)

    Aurora, Colorado, 80045

  • Our Lady of the Lake Children's Hospital ( Site 0031)

    Baton Rouge, Louisiana, 70809

  • The University of North Carolina at Chapel Hill ( Site 0035)

    Chapel Hill, North Carolina, 27514

  • Driscoll Children's Hospital ( Site 0025)

    Corpus Christi, Texas, 78411

  • Dayton Children's Hospital ( Site 0053)

    Dayton, Ohio, 45449

  • Duke University ( Site 0021)

    Durham, North Carolina, 27710

  • DHR Health Institute for Research and Development ( Site 0029)

    Edinburg, Texas, 78539

  • Tribe Clinical Research, LLC ( Site 0002)

    Greenville, South Carolina, 29607

  • Clinical Research Prime ( Site 0046)

    Idaho Falls, Idaho, 83404

  • University of Kentucky HealthCare - Turfland ( Site 0044)

    Lexington, Kentucky, 40536

  • Miller Children's & Women's Hospital Long Beach ( Site 0001)

    Long Beach, California, 90806

  • NYU Langone Hospital - Long Island-Pediatrics ( Site 0028)

    Mineola, New York, 11501

  • M Health Fairview University of Minnesota Masonic Children's Hospital, West Bank-Peds Research ( Site 0037)

    Minneapolis, Minnesota, 55454

  • Rutgers University-Pediatric Clinical Research Center ( Site 0007)

    New Brunswick, New Jersey, 08901

  • Tulane University School of Medicine ( Site 0010)

    New Orleans, Louisiana, 70112

  • Children's Hospital of Orange County ( Site 0047)

    Orange, California, 92868

  • Orlando Health - Arnold Palmer Hospital-Orlando Health-Arnold Palmer Hospital Pulmonary and Sleep M ( Site 0022)

    Orlando, Florida, 32806

  • Nemours Children's Health, Lake Nona Medical City ( Site 0032)

    Orlando, Florida, 32827

  • University of Rochester Medical Center ( Site 0017)

    Rochester, New York, 14642

  • Intermountain - Primary Children's Hospital ( Site 0026)

    Salt Lake City, Utah, 84113

  • Christus Children's-Clinical Research Center ( Site 0038)

    San Antonio, Texas, 78207

  • University Hospital-Pediatrics ( Site 0019)

    San Antonio, Texas, 78229

  • Road Runner Research, Ltd ( Site 0052)

    San Antonio, Texas, 78249

  • Multicare Rockwood Main Clinic-Rockwood Pediatrics ( Site 0004)

    Spokane, Washington, 99202

  • Providence Sacred Heart Medical Center & Children's Hospital ( Site 0030)

    Spokane, Washington, 99204

  • MultiCare Health System-Baker Center ( Site 0036)

    Tacoma, Washington, 98405

  • University of South Florida-Department of Pediatrics ( Site 0045)

    Tampa, Florida, 33606

  • Children's National Medical Center ( Site 0020)

    Washington D.C., District of Columbia, 20010

Other trials in United States

Spain10 sites
  • Hospital Germans Trias i Pujol ( Site 0738)

    Badalona, Barcelona, 08916

  • Hospital Universitario HM Monteprincipe-pediatric ( Site 0743)

    Boadilla del Monte, Madrid, 28660

  • Hospital Sant Joan de Déu ( Site 0730)

    Esplugues de Llobregat, Barcelona, 08950

  • Hospital Universitario 12 de Octubre-Unidad Pediátrica de Investigación y Ensayos Clínicos ( Site 0728)

    Madrid, Madrid, Comunidad de, 28041

  • Hospital Universitario La Paz ( Site 0726)

    Madrid, 28046

  • Grupo Pediatrico Uncibay ( Site 0734)

    Málaga, 29015

  • Hospital Universitario Central de Asturias ( Site 0740)

    Oviedo, Principality of Asturias, 33011

  • HOSPITAL UNIVERSITARIO QUIRONSALUD MADRID ( Site 0739)

    Pozuelo de Alarcón, Madrid, 28223

  • Hospital Universitary General de Catalunya-Pediatrics ( Site 0737)

    Sant Cugat del Vallès, Barcelona, 08195

  • CHUS - Hospital Clinico Universitario-Servicio de Pediatría ( Site 0731)

    Santiago de Compostela, La Coruna, 15706

Other trials in Spain

Germany9 sites
  • Universitaetsklinikum Carl Gustav Carus Dresden-Klinik und Poliklinik für Kinder- und Jugendmedizin ( Site 0363)

    Dresden, Saxony, 01307

  • Universitaetsklinikum Freiburg ( Site 0365)

    Freiburg im Breisgau, Baden-Wurttemberg, 79106

  • Medizinische Hochschule Hannover ( Site 0364)

    Hanover, Lower Saxony, 30625

  • Universitaetsklinikum Heidelberg-Zentrum für Kinder-und Jugendmedizin ( Site 0366)

    Heidelberg, Baden-Wurttemberg, 69120

  • Universitätsklinikum Leipzig-Neonatology ( Site 0354)

    Leipzig, Saxony, 04103

  • Universitätsklinikum Schleswig-Holstein-Pediatrics ( Site 0361)

    Lübeck, Schleswig-Holstein, 23538

  • Dr. von Haunersches Kinderspital ( Site 0358)

    Munich, Bavaria, 80337

  • München Klinik Harlaching ( Site 0351)

    Munich, Bavaria, 81545

  • Kinder und Jugendaerztliche Gemeinschaftspraxis Bedikian & Bouikidis ( Site 0359)

    Oberhausen, North Rhine-Westphalia, 46145

Other trials in Germany

Hungary8 sites
  • Bajai Szent Rókus Kórház ( Site 0386)

    Baja, Bács-Kiskun county

  • Péterfy Kórház-Rendelőintézet és Manninger Jenő Országos Traumatológiai Intézet-PIC ( Site 0384)

    Budapest, 1076

  • Semmelweis University-Szülészeti és Nőgyógyászati Klinika PIC ( Site 0381)

    Budapest, 1082

  • Gottsegen György Országos Kardiovaszkuláris Intézet ( Site 0383)

    Budapest, 1096

  • Debreceni Egyetem Klinikai Kozpont ( Site 0378)

    Debrecen, 4032

  • Bacs-Kiskun Megyei Korhaz-Pediatrics ( Site 0380)

    Kecskemét, Bács-Kiskun county, 6000

  • Borsod-Abaúj-Zemplén Megyei Központi Kórház és Egyetemi Oktatókórház-Újszülött Intenzív Osztály ( Site 0388)

    Miskolc, Borsod-Abauj Zemplen county, 3526

  • Szabolcs-Szatmar-Bereg Varmegyei Korhazak es Egyetemi Oktatokorhaz - Gyermekosztaly ( Site 0376)

    Nyíregyháza, Szabolcs-Szatmár-Bereg, 4400

Other trials in Hungary

Japan8 sites
  • Fukuoka Children's Hospital ( Site 0452)

    Fukuoka, Fukuoka, 813-0017

  • Iizuka Hospital ( Site 0457)

    Iizuka, Fukuoka, 820-8505

  • Japan Community Healthcare Organization Kyushu Hospital ( Site 0454)

    Kitakyushu-shi, Fukuoka, 806-8501

  • Maebashi Red Cross Hospital ( Site 0451)

    Maebashi, Gunma, 371-0811

  • Ibaraki Children's Hospital ( Site 0458)

    Mito, Ibaraki, 311-4145

  • Shizuoka Saiseikai General Hospital ( Site 0456)

    Shizuoka, 422-8527

  • Nihon University Itabashi Hospital ( Site 0453)

    tabashi City, Tokyo, 173-8610

  • National Center for Child Health and Development ( Site 0455)

    Tokyo, 157-8535

Other trials in Japan

United Kingdom8 sites
  • Queen Elizabeth University Hospital ( Site 0842)

    Glasgow, Glasgow City, G51 4TF

  • Alder Hey Children's Hospital-Paediatric Respiratory Medicine ( Site 0843)

    Liverpool, L12 2AP

  • Whipps Cross University Hospital ( Site 0846)

    London, England, E11 1NR

  • St. George's Hospital ( Site 0845)

    London, England, SW17 0RE

  • Evelina London Children's Hospital ( Site 0829)

    London, Great Britain, SE1 7EH

  • Barts Health NHS Trust-Children's Clinical Research Facility ( Site 0844)

    London, London, City of, E1 1BB

  • The John Radcliffe Hospital-Paediatrics Infectious Diseases ( Site 0827)

    Oxford, Oxfordshire, OX3 9DU

  • Southampton General Hospital ( Site 0826)

    Southampton, Hampshire, SO16 0YD

Other trials in United Kingdom

South Africa7 sites
  • Reimed ( Site 0706)

    Boksburg, Gauteng, 1459

  • Family Clinical Research Unit (Fam-Cru)-Pediatric ( Site 0703)

    Cape Town, Western Cape, 7500

  • Panorama Medical Centre ( Site 0702)

    Cape Town, Western Cape, 7500

  • MRC Unit on Child And Adolescent Health-Department of Paediatrics and child Health ( Site 0710)

    Cape Town, Western Cape, 7700

  • 2 Military Hospital ( Site 0708)

    Cape Town, Western Cape, 7824

  • King Edward VIII Hospital ( Site 0704)

    Durban, KwaZulu-Natal, 4001

  • Chris Hani Baragwanath Academic Hospital ( Site 0701)

    Soweto, Gauteng, 2013

Other trials in South Africa

Finland6 sites
  • MeVac - Meilahti Vaccine Research Center ( Site 0306)

    Helsinki, Uusimaa, 00290

  • FVR, Kokkolan rokotetutkimusklinikka ( Site 0304)

    Kokkola, Keski-Pohjanmaa, 67100

  • FVR, Oulun rokotetutkimusklinikka ( Site 0303)

    Oulu, North Ostrobothnia, 90220

  • FVR, Seinäjoen rokotetutkimusklinikka ( Site 0305)

    Seinäjoki, South Ostrobothnia, 60100

  • FVR, Tampereen rokotetutkimusklinikka ( Site 0301)

    Tampere, Pirkanmaa, 33100

  • FVR, Turun rokotetutkimusklinikka ( Site 0302)

    Turku, Southwest Finland, 20520

Other trials in Finland

Italy6 sites
  • Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico ( Site 0432)

    Milan, Lombardy, 20122

  • ASST Fatebenefratelli Sacco ( Site 0434)

    Milan, Lombardy, 20154

  • Azienda Ospedaliera di Padova-Department of Women and Child Health ( Site 0428)

    Padova, Veneto, 35128

  • Azienda Ospedaliero Universitaria di Parma-UO Clinica Pediatrica ( Site 0433)

    Parma, 43126

  • Ospedale Pediatrico Bambino Gesù IRCCS-UOC Broncopneumologia ( Site 0427)

    Rome, Lazio, 00165

  • Fondazione Policlinico Universitario Agostino Gemelli ( Site 0426)

    Rome, Lazio, 00168

Other trials in Italy

Malaysia6 sites
  • Hospital Pulau Pinang ( Site 0482)

    George Town, Pulau Pinang, 10450

  • Hospital Raja Perempuan Zainab II-Department of Pediatric ( Site 0477)

    Kota Bharu, Kelantan, 15586

  • Sabah Women and Children Hospital ( Site 0478)

    Kota Kinabalu, Sabah, 88996

  • Hospital Tunku Azizah-Paediatric ( Site 0481)

    Kuala Lumpur, 50300

  • University Malaya Medical Centre-Department of Paediatrics ( Site 0480)

    Lembah Pantai, Kuala Lumpur, 59100

  • Hospital Sibu ( Site 0476)

    Sibu, Sarawak, 96000

Other trials in Malaysia

Mexico6 sites
  • Instituto de Investigaciones Aplicadas a la Neurociencia A.C. ( Site 0508)

    Durango, 34000

  • Centro de Investigación Médico Biológica y Terapia Avanzada ( Site 0502)

    Guadalajara, Jalisco, 44650

  • Morales Vargas Centro de Investigacion ( Site 0509)

    León, Guanajuato, 37000

  • Instituto Nacional de Pediatria ( Site 0506)

    Mexico City, Mexico City, 04530

  • Oaxaca Site Management Organization ( Site 0504)

    Oaxaca City, 68000

  • ONCOLOGICO POTOSINO, S.C. ( Site 0505)

    San Luis Potosí City, 78209

Other trials in Mexico

Colombia5 sites
  • Ciensalud Ips S A S ( Site 0235)

    Barranquilla, Atlántico, 08001

  • Sociedad de Cirugía de Bogotá - Hospital de San Jose ( Site 0230)

    Bogotá, Bogota D.C., 111411

  • Clínica Imbanaco S.A.S ( Site 0229)

    Cali, Valle del Cauca Department, 760042

  • Fundación Hospitalaria San Vicente de Paúl ( Site 0233)

    Medellín, Antioquia, 050010

  • Clínica Universitaria Bolivariana ( Site 0227)

    Medellín, Antioquia, 50036

Other trials in Colombia

Turkey (Türkiye)5 sites
  • Ankara University Hospital Cebeci ( Site 0801)

    Ankara, 06100

  • Gazi Universitesi ( Site 0806)

    Ankara, 06560

  • Ankara Bilkent Şehir Hastanesi. ( Site 0807)

    Ankara, 06800

  • Erciyes University Medical Faculty-pediatric infection ( Site 0804)

    Kayseri, 38039

  • cukurova universty ( Site 0805)

    Sarçam, Adana, 01030

Other trials in Turkey (Türkiye)

Greece4 sites
  • Aghia Sophia Children's Hospital-First Department of Pediatrics, National and Kapodistrian Universi ( Site 0852)

    Athens, Attica, 115 27

  • Children's Hospital Aglaia Kyriakou-2nd Department of Pediatrics NKUA ( Site 0854)

    Athens, Attica, 115 27

  • ATTIKON GENERAL UNIVERSITY HOSPITAL-3rd Department of Pediatrics ( Site 0855)

    Chaïdári, Attica, 124 62

  • Hippokration University Hopsital-3rd Pediatric Department ( Site 0851)

    Thessaloniki, Central Macedonia, 54642

Other trials in Greece

Taiwan4 sites
  • Taichung Veterans General Hospital ( Site 0754)

    Taichung, 407

  • National Taiwan University Hospital ( Site 0751)

    Taipei, 10002

  • Mackay Memorial Hospital-Pediatrics ( Site 0753)

    Taipei, 10449

  • Chang Gung Medical Foundation-Linkou Branch ( Site 0752)

    Taoyuan, 33305

Other trials in Taiwan

Canada3 sites
  • Alberta Children's Hospital-Department of Pediatrics ( Site 0180)

    Calgary, Alberta, T3B 6A8

  • Canadian Center for Vaccinology ( Site 0179)

    Halifax, Nova Scotia, B3K 6R8

  • CHU Sainte-Justine ( Site 0178)

    Montreal, Quebec, H3T 1C5

Other trials in Canada

Chile3 sites
  • Clínica Alemana de Santiago-Neonatology department ( Site 0207)

    Santiago, Region M. de Santiago, 8320325

  • Hospital Roberto del Río-Infectología Pediátrica ( Site 0205)

    Santiago, Region M. de Santiago, 8380418

  • Hospital Padre Hurtado-NEONATOLOGY/PEDIATRICS ( Site 0201)

    Santiago, Region M. de Santiago, 8880465

Other trials in Chile

France3 sites
  • Bordeaux University Hospital - Pellegrin-Pediatrics ( Site 0332)

    Bordeaux, Aquitaine, 33076

  • Centre Hospitalier Universitaire de Caen - Hôpital Côte de N-Centre de Recherche Clinique Pédiatriq ( Site 0330)

    Caen, Calvados, 14033

  • Centre Hospitalier de Versailles André Mignot-NEONATOLOGY ( Site 0331)

    Le Chesnay, Yvelines, 78157

Other trials in France

Thailand3 sites
  • Chulalongkorn University-Pediatrics ( Site 0777)

    Bangkok, Bangkok, 10330

  • Faculty of Medicine Siriraj Hospital-Pediatric Infectious Diseases ( Site 0778)

    Bangkok, Bangkok, 10700

  • Songklanagarind hospital-Department of Pediatrics ( Site 0776)

    Hat Yai, Changwat Songkhla, 90110

Other trials in Thailand

Australia2 sites
  • Mater Misericordiae Limited-Neonatalogy ( Site 0102)

    Brisbane, Queensland, 4101

  • Telethon Kids Institute-Vaccine Trials Group ( Site 0101)

    Nedlands, Western Australia, 6009

Other trials in Australia

Czechia2 sites
  • Fakultni nemocnice Ostrava-Oddeleni neonatologie ( Site 0252)

    Ostrava, Moravian-Silesian Region, 708 52

  • Institute for the Care of Mother and Child ( Site 0251)

    Prague, Praha 4, 14700

Other trials in Czechia

Hong Kong2 sites
  • Prince of Wales Hospital ( Site 0926)

    Shatin

  • Tuen Mun Hospital ( Site 0927)

    Tuenmen, 999077

Other trials in Hong Kong

New Zealand2 sites
  • Middlemore Clinical Trials ( Site 0526)

    Auckland, 2025

  • Capital and Coast District Health Board-Clinical Trials Unit ( Site 0527)

    Newtown, Wellington Region, 6021

Other trials in New Zealand

Peru2 sites
  • Instituto Nacional Cardiovascular INCOR Carlos Peschiera Carrillo - EsSalud ( Site 0577)

    Jesús María, Lima, 15072

  • HOSPITAL DOCENTE MADRE-NIÑO SAN BARTOLOME-NEUMOLOGIA PEDIATRICA ( Site 0576)

    Lima, 15001

Other trials in Peru

Norway1 site
  • Oslo Universitetssykehus Ullevål ( Site 0551)

    Oslo, 0450

Other trials in Norway

Puerto Rico1 site
  • UPR Medical Sciences Campus-Pediatrics ( Site 0626)

    San Juan, 00935

Other trials in Puerto Rico

Singapore1 site
  • KK Women's and Children's Hospital-Department of Neonatology ( Site 0877)

    Singapore, South West, 229899

Other trials in Singapore

About this study

Official title: A Phase 3, Multicenter, Randomized, Partially Blinded, Palivizumab- Controlled Study to Evaluate the Safety, Efficacy, and Pharmacokinetics of MK-1654 in Infants and Children at Increased Risk for Severe RSV Disease

This study aims to evaluate the safety and tolerability of clesrovimab compared to palivizumab as assessed by the proportion of participants experiencing adverse events (AEs).

Conditions
RSV Infection
Being tested
Clesrovimab, Palivizumab, Placebo
Medical subject headings
Respiratory Syncytial Virus Infections

What participants receive

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

  • ClesrovimabBiological

    Also called MK-1654

    IM injection

  • PalivizumabBiological

    Also called Synagis™

    IM injection

  • PlaceboBiological

    IM injection

Study groups in NCT04938830
Study groupRoleWhat they receive
ClesrovimabExperimentalParticipants will receive intramuscular (IM) injections of clesrovimab and placebo
Receives: Biological: Clesrovimab; Biological: Placebo
PalivizumabActive comparatorParticipants will receive IM injections.
Receives: Biological: Palivizumab

What is being measured

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

  1. Number of Participants With Solicited Injection-site Adverse Events (AEs) in RSV Season 1

    An AE is 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. Solicited injection-site AEs included erythema, pain, and swelling. The number of participants with solicited injection-site AEs in RSV Season 1 is reported.

    Measured: Up to 5 days after each dose in RSV Season 1 (Up to ~33 days)

  2. Number of Participants With Solicited Daily Body Temperatures With Fever in RSV Season 1

    Fever was defined as maximum rectal temperature ≥102.2 °F (39.0 °C) or maximum axillary temperature ≥101.7 °F. The number of participants with solicited daily body temperature of fever in RSV Season 1 is reported.

    Measured: Up to 5 days after each dose in RSV Season 1 (Up to ~33 days)

  3. Number of Participants With Solicited Systemic AEs in RSV Season 1

    An AE is 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. Solicited systemic AEs included decreased appetite, irritability, and somnolence. The number of participants with solicited systemic AEs in RSV Season 1 is reported.

    Measured: Up to 5 days after each dose in RSV Season 1 (Up to ~33 days)

  4. Number of Participants With Anaphylaxis/Hypersensitivity AEs of Special Interest (AESI) in RSV Season 1

    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. The number of participants with anaphylaxis/hypersensitivity AESI in RSV Season 1 is reported.

    Measured: Up to 42 days in RSV Season 1

  5. Number of Participants With Rash AESI in RSV Season 1

    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. Rash AESI included urticaria and drug eruption. The number of participants with rash AESI in RSV Season 1 is reported.

    Measured: Up to 42 days in RSV Season 1

  6. Number of Participants With Nonserious AEs in RSV Season 1

    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. The number of participants with nonserious AEs in RSV Season 1 is reported.

    Measured: Up to 42 days in RSV Season 1

  7. Number of Participants With Serious AEs (SAEs) Through the Duration of Participation in RSV Season 1

    An SAE is any untoward medical occurrence in a clinical study participant that results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect, or is another important medical event. The number of participants with SAEs in RSV Season 1 is reported.

    Measured: Up to 365 days in RSV Season 1

Secondary outcomes (11)
  1. Number of Cases of RSV-associated Medically Attended Lower Respiratory Infection (MALRI) in RSV Season 1

    Outpatient and inpatient MALRI was defined as the presence of the following in a clinical setting: 1) cough or difficulty breathing; AND 2) 1 or more of wheezing, chest wall in-drawing/retraction, rales/crackles, hypoxemia, tachypnea, or dehydration due to respiratory symptoms; AND 3) RSV-positive reverse transcriptase polymerase chain reaction (RT-PCR) nasopharyngeal (NP) sample. The number of cases of outpatient and inpatient RSV-associated MALRI were reported together for RSV season 1. For each participant, only the first occurrence of the case is counted for the analysis.

    Measured: Up to 150 days in RSV Season 1

  2. Number of Cases of RSV-associated Hospitalization in RSV Season 1

    RSV-associated hospitalization is defined as a hospital admission for respiratory illness and RSV-positive RT-PCR NP sample. The number of cases of RSV-associated hospitalization in RSV Season 1 is reported. For each participant, only the first occurrence of the case is counted for the analysis.

    Measured: Up to 150 days in RSV Season 1

  3. Number of Participants With Solicited Injection-site AEs in RSV Season 2

    An AE is 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. Solicited injection-site AEs included erythema, pain, and swelling. The number of participants with solicited injection-site AEs in RSV Season 2 is reported.

    Measured: Up to 5 days postdose in RSV Season 2 (Up to ~400 days)

  4. Number of Participants With Solicited Daily Body Temperature With Fever in RSV Season 2

    Fever was defined as maximum rectal temperature ≥102.2 °F (39.0 °C) or maximum axillary temperature ≥101.7 °F. The number of participants with solicited daily body temperature of fever in RSV Season 2 is reported.

    Measured: Up to 5 days postdose in RSV Season 2 (Up to ~400 days)

  5. Number of Participants With Solicited Systemic AEs in RSV Season 2

    An AE is 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. Solicited systemic AEs included decreased appetite, irritability, and somnolence. The number of participants with solicited systemic AEs in RSV Season 2 is reported.

    Measured: Up to 5 days postdose in RSV Season 2 (Up to ~400 days)

  6. Number of Participants With Anaphylaxis/Hypersensitivity AESI in RSV Season 2

    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. The number of participants with anaphylaxis/hypersensitivity AESI in RSV Season 2 is reported.

    Measured: Up to 42 days postdose in RSV Season 2 (Up to ~440 days)

  7. Number of Participants With Rash AESI in RSV Season 2

    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. Rash AESI included urticaria and drug eruption. The number of participants with rash AESI in RSV Season 2 is reported.

    Measured: Up to 42 days postdose in RSV Season 2 (Up to ~440 days)

  8. Number of Participants With Nonserious AEs in RSV Season 2

    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. The number of participants with nonserious AEs in RSV Season 2 is reported.

    Measured: Up to 42 days postdose in RSV Season 2 (Up to ~440 days)

  9. Number of Participants With SAEs in RSV Season 2

    An SAE is any untoward medical occurrence in a clinical study participant that results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect, or is another important medical event. The number of participants with SAEs in RSV Season 2 is reported.

    Measured: Up 180 days postdose in RSV Season 2 (Up to ~575 days)

  10. Concentration of Clesrovimab in RSV Season 1

    Blood samples were collected to determine the serum concentration of clesrovimab at Days 7, 150, and 240 in RSV Season 1.

    Measured: At Day 7, Day 150, and Day 240 in RSV Season 1

  11. Concentration of Clesrovimab in RSV Season 2

    Blood samples were collected to determine the serum concentration of clesrovimab at Days 7 and 150 in RSV Season 2. RSV Season 2 began 246-393 days after RSV Season 1 dose 1.

    Measured: At Day 7 and Day 150 postdose in RSV Season 2

Timeline

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

  1. First posted24 Jun 2021
  2. Study start30 Nov 2021
  3. Primary completion28 Apr 2025
  4. Study completion1 Aug 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
Masking
Triple blind
Who is masked
Participant, Care provider, Investigator
Enrolment
1,003 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04938830
Sponsor's protocol ID
1654-007
Other IDs
MK-1654-007, jRCT2031210664, 2022-500752-39-00, U1111-1278-0093, 2020-005996-11
Acronym
SMART
Status last verified
Apr 2026
First submitted
22 Jun 2021
Last updated
8 May 2026
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf

Publications

  • Zar HJ, Bont LJ, Manzoni P, Munoz FM, Ramilo O, Chen PY, Novoa JM, Ordonez GA, Tsolia M, Tapiero B, Acuna-Avila MI, Castellanos JM, Meyer M, Morioka I, Chen Z, Railkar RA, Zang X, Maas BM, Likos A, Lee AW, Castagnini LA, Sinha A; SMART (MK-1654-007) Study Group. Clesrovimab in Infants and Children at Increased Risk for Severe RSV Disease. N Engl J Med. 2025 Oct 2;393(13):1343-1345. doi: 10.1056/NEJMc2506107. Epub 2025 Sep 17. No abstract available.

    PubMed 40961423
  • Zar HJ, Bont LJ, Manzoni P, Munoz FM, Ramilo O, Chen PY, Novoa JM, Ordonez GA, Tsolia M, Tapiero B, Acuna-Avila MI, Castellanos JM, Meyer M, Morioka I, Heinonen S, Chen Z, Zeng T, Railkar RA, Arriola CS, Zang X, Hildebrand C, Maestri A, Castagnini LA, Sinha A; SMART (MK-1654-007) study group. Clesrovimab in Infants at Increased Risk For Severe Disease During 2 RSV Seasons: A Randomized Clinical Trial. JAMA Pediatr. 2026 Jul 20:e262760. doi: 10.1001/jamapediatrics.2026.2760. Online ahead of print.

    PubMed 42475081
  • Sinha A, Railkar RA, Castagnini L, Guerra A, Likos A, Lutkiewicz J, Maas BM, Zang X, Roadcap BA, Choi Y, Nahhas GJ, Arriola CS, Bont L, Manzoni P, Ramilo O, Munoz FM, Finelli L, Lee AW. Evaluation of a monoclonal antibody against respiratory syncytial virus, clesrovimab, in infants and children: Comprehensive rationale and study design for the late-stage clinical trials. Contemp Clin Trials. 2025 Oct;157:107995. doi: 10.1016/j.cct.2025.107995. Epub 2025 Jun 30.

    PubMed 40602662

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Clesrovimab and Palivizumab in people with RSV Infection, run by Merck Sharp & Dohme LLC at 146 sites in 27 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 11 inclusion and 8 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 8 May 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 146 sites in United States, Spain, Germany, Hungary, Japan and 22 more countries. 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 8 May 2026). 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 Solicited Injection-site Adverse Events (AEs) in RSV Season 1 (time frame: Up to 5 days after each dose in RSV Season 1 (Up to ~33 days)). The study lists 7 primary outcomes in all. 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 NCT04938830, which also lists 3 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 8 May 2026.

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