Efficacy and Safety of Clesrovimab (MK-1654) in Infants (MK-1654-004) (CLEVER)

A Phase 2b/3 Double-Blind, Randomized, Placebo-Controlled Study to Evaluate the Efficacy and Safety of MK-1654 in Healthy Pre-Term and Full-Term Infants

The primary objectives of this phase 2b/3 double-blind, randomized, placebo-controlled study are to evaluate the efficacy and safety of clesrovimab in healthy pre-term and full-term infants. It is hypothesized that clesrovimab will reduce the incidence of respiratory syncytial virus (RSV)-associated medically attended lower respiratory infection (MALRI) from Days 1 through 150 postdose compared to placebo.

Study Overview

• Status: Completed
• Conditions: Respiratory Syncytial Virus Infection
• Intervention / Treatment: Biological: Clesrovimab; Drug: Placebo

• Study Type: Interventional
• Enrollment (Actual): 3632
• Phase: Phase 2; Phase 3

Contacts and Locations

Study Locations

• Argentina
  • Buenos Aires, Argentina, C1425DND
    • SANATORIO MATER DEI ( Site 1010)
  • Córdoba, Argentina, X5000IIH
    • Clinica Privada del Sol S.A ( Site 1013)
  • Buenos Aires
    • Ciudad Autonoma de Buenos Aires, Buenos Aires, Argentina, C1426BOS
      • Hospital Militar Central Cir Mayor Cosme Argerich ( Site 1001)
    • Mar de La Plata, Buenos Aires, Argentina, B7600FYH
      • Clinica del Nino y la Madre ( Site 1005)
  • Córdoba Province
    • Córdoba, Córdoba Province, Argentina, 5004
      • SANATORIO DEL SALVADOR-Pediatria ( Site 1008)
• Belgium
  • Antwerpen
    • Edegem, Antwerpen, Belgium, 2650
      • Universitair Ziekenhuis Antwerpen ( Site 2001)
  • Bruxelles-Capitale, Region de
    • Brussels, Bruxelles-Capitale, Region de, Belgium, 1000
      • Centre Hospitalier Universitaire Saint Pierre (Bruxelles) ( Site 2003)
    • Brussels, Bruxelles-Capitale, Region de, Belgium, 1200
      • Cliniques Universitaires Saint-Luc ( Site 2005)
  • Wallonne, Region
    • Gozée, Wallonne, Region, Belgium, 6534
      • Cabinet Médical Demeulemeester ( Site 2002)
  • West-Vlaanderen
    • Roeselare, West-Vlaanderen, Belgium, 8800
      • AZ Delta ( Site 2004)
• Canada
  • Alberta
    • Calgary, Alberta, Canada, T3B 6A8
      • University of Calgary - Alberta Children Hospital ( Site 0504)
  • British Columbia
    • Vancouver, British Columbia, Canada, V6H 3N1
      • BC Women s Hospital and Health Centre ( Site 0506)
  • Nova Scotia
    • Halifax, Nova Scotia, Canada, B3K 6R8
      • Canadian Center for Vaccinology ( Site 0503)
  • Ontario
    • Hamilton, Ontario, Canada, L8M 1K7
      • Hamilton Medical Research Group ( Site 0509)
  • Quebec
    • Montreal, Quebec, Canada, H3T 1C5
      • CHU Sainte Justine ( Site 0502)
    • Pierrefonds, Quebec, Canada, H9H 4Y6
      • McGill University Health Centre - Vaccine Study Centre ( Site 0500)
    • Québec, Quebec, Canada, G1E 7G9
      • CHU de Quebec Universite de Laval ( Site 0501)
• Chile
  • Region M. de Santiago
    • Santiago, Region M. de Santiago, Chile, 8242238
      • Hospital La Florida ( Site 1104)
    • Santiago, Region M. de Santiago, Chile, 8380418
      • Hospital Roberto del Rio ( Site 1106)
    • Santiago, Region M. de Santiago, Chile, 8380453
      • Facultad Medicina Universidad de Chile ( Site 1105)
    • Santiago, Region M. de Santiago, Chile, 8880465
      • Hospital Padre Hurtado ( Site 1101)
• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 100091
      • Peking University Third Hospital ( Site 3339)
  • Chongqing Municipality
    • Chongqing, Chongqing Municipality, China, 400065
      • The Children's Hospital of Chongqing Medical University ( Site 3333)
    • Chongqing, Chongqing Municipality, China, 402260
      • Jiangjin District Central Hospital ( Site 3319)
  • Fujian
    • Xiamen, Fujian, China, 361003
      • Xiamen Maternity and Child Health Care Hospital ( Site 3351)
  • Guangdong
    • Guangzhou, Guangdong, China, 510080
      • Guangdong Provincial People's Hospital ( Site 3341)
    • Guangzhou, Guangdong, China, 510150
      • The Third Affiliated Hospital of Guangzhou Medical University ( Site 3348)
    • Guangzhou, Guangdong, China, 511400
      • Guangdong Maternity and Child Health Care Hospital ( Site 3340)
  • Guangxi
    • Liuchow, Guangxi, China, 545006
      • Liuzhou People's Hospital ( Site 3364)
  • Hebei
    • Langfang, Hebei, China, 065000
      • Hebei Petro China Central Hospital ( Site 3365)
    • Shijiazhuang, Hebei, China, 050035
      • Fourth Hospital of Hebei Medical University ( Site 3366)
  • Henan
    • Sanmenxia, Henan, China, 472000
      • Sanmenxia Central Hospital ( Site 3360)
  • Hubei
    • Wuhan, Hubei, China, 430000
      • Wuhan Children's Hospital ( Site 3329)
    • Wuhan, Hubei, China, 430060
      • Renmin Hospital of Wuhan University ( Site 3316)
  • Hunan
    • Changde, Hunan, China, 415000
      • Changde First People's Hospital ( Site 3311)
    • Changsha, Hunan, China, 410000
      • The Maternal and Child Health Hospital of Hunan Province ( Site 3334)
    • Changsha, Hunan, China, 410005
      • Hunan Provincial People's Hospital ( Site 3355)
    • Changsha, Hunan, China, 410008
      • Xiangya Hospital Central South University ( Site 3347)
    • Shaoyang, Hunan, China, 422000
      • Hunan Shaoyang No.1 People's Hospital ( Site 3345)
  • Jiangsu
    • Nanjing, Jiangsu, China, 210009
      • Zhongda Hospital Southeast University ( Site 3353)
  • Jiangxi
    • Nanchang, Jiangxi, China, 330006
      • Jiangxi Provincial Children's Hospital ( Site 3313)
    • Nanchang, Jiangxi, China, 330009
      • The Third Hospital of Nanchang ( Site 3325)
    • Pingxiang, Jiangxi, China, 337000
      • Jiangxi Pingxiang People's Hospital ( Site 3312)
  • Liaoning
    • Dalian, Liaoning, China, 116012
      • Dalian Women and Children Medical Treatment Center(Hope Square Children's Branch Hospital) ( Site 33
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China, 201102
      • Children's Hospital of Fudan University ( Site 3361)
  • Shanxi
    • Linfen, Shanxi, China, 041000
      • Linfen Central Hospital ( Site 3368)
    • Linfen, Shanxi, China, 041081
      • Linfen People's Hospital ( Site 3363)
    • Yuncheng, Shanxi, China, 044000
      • Yuncheng Central Hospital - Eastern Hospital ( Site 3318)
  • Sichuan
    • Chengdu, Sichuan, China, 610091
      • Chengdu Women and Children Center Hospital ( Site 3332)
  • Zhejiang
    • Hangzhou, Zhejiang, China, 310006
      • The First People's Hospital of Hangzhou ( Site 3342)
    • Ningbo, Zhejiang, China, 315012
      • Ningbo Women and Children's Hospital ( Site 3314)
• Colombia
  • Antioquia
    • Medellín, Antioquia, Colombia, 050036
      • Universidad Pontificia Bolivariana - Clinica Universitaria Bolivariana ( Site 1154)
    • Rionegro, Antioquia, Colombia, 054040
      • Sociedad Medica de Rionegro SOMER S.A. ( Site 1157)
  • Atlántico
    • Barranquilla, Atlántico, Colombia, 080020
      • Clinica de la Costa S.A.S. ( Site 1152)
  • Cundinamarca
    • Chía, Cundinamarca, Colombia, 250001
      • Centro de Atención e Investigación Médica SAS - CAIMED CHIA ( Site 1155)
  • Valle del Cauca Department
    • Cali, Valle del Cauca Department, Colombia, 760001
      • Centro de Estudios en Infectologia Pediatrica SAS ( Site 1159)
• Denmark
  • Central Jutland
    • Herning, Central Jutland, Denmark, 7400
      • Regionshospitalet Herning ( Site 2105)
  • North Denmark
    • Aalborg, North Denmark, Denmark, 9000
      • Aalborg Universitetshospital, Nord-Børne- og Ungeafdelingen ( Site 2100)
    • Hjørring, North Denmark, Denmark, 9800
      • Regionshospitalet Nordjylland ( Site 2102)
  • Region Syddanmark
    • Odense, Region Syddanmark, Denmark, 5000
      • Odense University Hospital ( Site 2107)
• Finland
  • Keski-Pohjanmaa
    • Kokkola, Keski-Pohjanmaa, Finland, 67100
      • FVR, Kokkolan rokotetutkimusklinikka ( Site 2157)
  • North Ostrobothnia
    • Oulu, North Ostrobothnia, Finland, 90220
      • FVR, Oulun rokotetutkimusklinikka ( Site 2158)
  • Pirkanmaa
    • Tampere, Pirkanmaa, Finland, 33100
      • Tampereen yliopisto - Tampereen rokotetutkimusklinikka ( Site 2160)
  • Satakunta
    • Pori, Satakunta, Finland, 28100
      • FVR, Porin rokotetutkimusklinikka ( Site 2156)
  • South Ostrobothnia
    • Seinäjoki, South Ostrobothnia, Finland, 60100
      • FVR, Seinäjoen rokotetutkimusklinikka ( Site 2155)
  • Southwest Finland
    • Turku, Southwest Finland, Finland, 20520
      • FVR, Turun rokotetutkimusklinikka ( Site 2151)
  • Uusimaa
    • Espoo, Uusimaa, Finland, 02230
      • FVR, Espoon rokotetutkimusklinikka ( Site 2152)
    • Helsinki, Uusimaa, Finland, 00100
      • FVR, Etelä-Helsingin rokotetutkimusklinikka ( Site 2159)
    • Helsinki, Uusimaa, Finland, 00930
      • FVR, Itä-Helsingin rokotetutkimusklinikka ( Site 2153)
    • Jarvenpaa, Uusimaa, Finland, 04400
      • FVR, Järvenpään rokotetutkimusklinikka ( Site 2154)
• France
  • Calvados
    • Caen, Calvados, France, 14033
      • CHU Caen ( Site 2212)
  • Gironde
    • Bordeaux, Gironde, France, 33000
      • Groupe Hospitalier Pellegrin ( Site 2218)
  • Yvelines
    • Le Chesnay, Yvelines, France, 78150
      • Centre Hospitalier de Versailles ( Site 2206)
• Israel
  • Beersheba, Israel, 8410101
    • Soroka Medical Center ( Site 2351)
  • Beersheba, Israel, 8471844
    • Soroka University Medical Center Ramot Family health center ( Site 2354)
  • Haifa, Israel, 3525408
    • Rambam Medical Center ( Site 2352)
  • Rahat, Israel, 8535700
    • Soroka University Medical Center Rahat Family health center ( Site 2355)
  • Ramat Gan, Israel, 5265601
    • Chaim Sheba Medical Center ( Site 2353)
• Italy
  • Bari, Italy, 70124
    • A.O. Policlinico Consorziale di Bari ( Site 2309)
  • Milan, Italy, 20122
    • Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico ( Site 2310)
  • Roma
    • Rome, Roma, Italy, 00168
      • Policlinico Universitario Gemelli ( Site 2301)
  • Tuscany
    • Florence, Tuscany, Italy, 50139
      • A.O.Universitaria Meyer ( Site 2306)
  • Veneto
    • Padua, Veneto, Italy, 35128
      • Universita degli studi di Padova Patologia e TIN ( Site 2305)
• Japan
  • Fukui, Japan, 910-0833
    • Fukui Aiiku Hospital ( Site 3056)
  • Fukui, Japan, 918-8503
    • Fukui-ken Saiseikai Hospital ( Site 3064)
  • Saitama, Japan, 336-8522
    • Saitama City Hospital ( Site 3055)
  • Shizuoka, Japan, 424-8636
    • Shizuoka City Shimizu Hospital ( Site 3061)
  • Tokyo, Japan, 104-8560
    • St.Luke's International Hospital ( Site 3062)
  • Tokyo, Japan, 142-8666
    • Showa University Hospital ( Site 3059)
  • Gunma
    • Maebashi, Gunma, Japan, 371-0811
      • Maebashi Red Cross Hospital ( Site 3057)
  • Kanagawa
    • Kawasaki, Kanagawa, Japan, 216-8511
      • St. Marianna University School of Medicine Hospital ( Site 3060)
    • Yokohama, Kanagawa, Japan, 222-0036
      • JOHAS Yokohama Rosai Hospital ( Site 3058)
  • Oita Prefecture
    • Beppu, Oita Prefecture, Japan
      • National Hospital Organization Beppu Medical Center ( Site 3063)
  • Saitama
    • Ageo, Saitama, Japan, 362-8588
      • Ageo Central General Hospital ( Site 3051)
  • Tottori
    • Yonago, Tottori, Japan, 683-8504
      • Tottori University Hospital ( Site 3053)
• Malaysia
  • Kelantan
    • Kota Bharu, Kelantan, Malaysia, 15586
      • Hospital Raja Perempuan Zainab II ( Site 3106)
  • Perak
    • Seri Manjung, Perak, Malaysia, 32040
      • Hospital Seri Manjung ( Site 3103)
    • Taiping, Perak, Malaysia, 34000
      • Hospital Taiping ( Site 3108)
  • Pulau Pinang
    • George Town, Pulau Pinang, Malaysia, 10990
      • Hospital Pulau Pinang ( Site 3104)
    • Seberang Jaya, Pulau Pinang, Malaysia, 13700
      • Hospital Seberang Jaya ( Site 3107)
  • Sabah
    • Kota Kinabalu, Sabah, Malaysia, 88996
      • Sabah Womens & Childrens Hospital ( Site 3102)
  • Sarawak
    • Sibu, Sarawak, Malaysia, 96000
      • Hospital Sibu ( Site 3101)
• Mexico
  • Aguascalientes, Mexico, 20259
    • Centenario Hospital Miguel Hidalgo ( Site 1204)
  • Huixquilucan, Mexico, 52763
    • Hospital Angeles Lomas ( Site 1207)
  • Mexico City, Mexico, 04530
    • Instituto Nacional de Pediatria ( Site 1202)
  • Mexico City
    • Mexico City, Mexico City, Mexico, 06760
      • CAIMED Investigación en Salud S.A de C.V ( Site 1209)
• Peru
  • Lima, Peru, 15001
    • Hospital Nacional Docente Madre - Nino San Bartolome ( Site 1251)
  • Lima, Peru, LIMA 36
    • Instituto de Investigacion Nutricional - Anexo Huascar ( Site 1252)
  • La Libertad
    • Trujillo, La Libertad, Peru, 13011
      • Clinica Peruano Americana S.A. ( Site 1253)
  • Loreto
    • Iquitos, Loreto, Peru, 16001
      • Asociacion Civil Selva Amazonica ( Site 1255)
• Philippines
  • National Capital Region
    • Manila, National Capital Region, Philippines, 1000
      • University of the Philippines-Philippine General Hospital ( Site 3152)
    • Quezon City, National Capital Region, Philippines, 1100
      • Philippine Children s Medical Center ( Site 3154)
    • Quezon City, National Capital Region, Philippines, 1118
      • Far Eastern University - Nicanor Reyes Medical Foundation ( Site 3153)
• Poland
  • Greater Poland Voivodeship
    • Poznan, Greater Poland Voivodeship, Poland, 60-129
      • Instytut Mikroekologii Sp. Z o.o. & Co. Sp. Komandytowa ( Site 2412)
  • Kuyavian-Pomeranian Voivodeship
    • Bydgoszcz, Kuyavian-Pomeranian Voivodeship, Poland, 85-048
      • IN VIVO ( Site 2401)
  • Lesser Poland Voivodeship
    • Krakow, Lesser Poland Voivodeship, Poland, 31-411
      • Centrum Medyczne PROMED ( Site 2432)
    • Tarnów, Lesser Poland Voivodeship, Poland, 33-100
      • Alergo-Med Specjalistyczna Przychodnia Lekarska SP ( Site 2403)
  • Lower Silesian Voivodeship
    • Trzebnica, Lower Silesian Voivodeship, Poland, 55-100
      • Szpital im. sw. Jadwigi Slaskiej w Trzebnicy ( Site 2409)
    • Wroclaw, Lower Silesian Voivodeship, Poland, 50-368
      • Uniwersytecki Szpital Kliniczny-Klinika Pediatrii i Chorob Infekcyjnych ( Site 2440)
  • Lublin Voivodeship
    • Lublin, Lublin Voivodeship, Poland, 20-093
      • Uniwersytecki Szpital Dzieciecy w Lublinie ( Site 2404)
    • Łęczna, Lublin Voivodeship, Poland, 21-010
      • NZOZ Salmed ( Site 2433)
  • Masovian Voivodeship
    • Mazowieckie, Masovian Voivodeship, Poland, 02-972
      • MTL Centrum Medyczne Puławska Społka zoo Sp K. ( Site 2426)
    • Warsaw, Masovian Voivodeship, Poland, 00-315
      • Szpital Kliniczny im Ks Anny Mazowieckiej ( Site 2435)
    • Warsaw, Masovian Voivodeship, Poland, 00-728
      • WIP Warsaw IBD Point Profesor Kierkus ( Site 2441)
    • Warsaw, Masovian Voivodeship, Poland, 01-809
      • Szpital Bielanski im. Ks. Jerzego Popiełuszki SPZOZ ( Site 2425)
    • Warsaw, Masovian Voivodeship, Poland, 01-868
      • Centrum Medyczne Pratia Warszawa ( Site 2438)
  • Pomeranian Voivodeship
    • Gdansk, Pomeranian Voivodeship, Poland, 80-214
      • Uniwersyteckie Centrum Kliniczne ( Site 2437)
  • Silesian Voivodeship
    • Tychy, Silesian Voivodeship, Poland, 43-100
      • Szpital Miejski w Tychach ( Site 2442)
  • Łódź Voivodeship
    • Lodz, Łódź Voivodeship, Poland, 91-347
      • Gravita Diagnostyka i Leczenie Nieplodnosci ( Site 2423)
• Romania
  • Brasov, Romania, 500063
    • Spitalul Clinic de Urgenta pentru Copii Brasov ( Site 2456)
  • Bucharest, Romania, 011171
    • Spitalul Clinic "Filantropia" Clinica Obstetrica-Ginecologie ( Site 2451)
  • Constanța, Romania, 900591
    • Spitalul Clinic Judetean De Urgenta Constanta ( Site 2458)
  • Iași, Romania, 700038
    • Spitalul Cinic de Obstretica si Ginecologie Cuza Voda ( Site 2452)
• South Africa
  • Free State
    • Bloemfontein, Free State, South Africa, 9301
      • University Of The Orange Free State ( Site 2507)
  • Gauteng
    • Johannesburg, Gauteng, South Africa, 2013
      • Baragwanath Hospital ( Site 2501)
    • Johannesburg, Gauteng, South Africa, 2093
      • Empilweni Services and Research Unit ( Site 2504)
    • Pretoria, Gauteng, South Africa, 0002
      • Steve Biko Academic Hospital ( Site 2505)
  • KwaZulu-Natal
    • Durban, KwaZulu-Natal, South Africa, 4013
      • Enhancing Care Foundation-DICRS ( Site 2506)
  • Western Cape
    • Cape Town, Western Cape, South Africa, 7505
      • Tygerberg Hospital ( Site 2503)
    • Cape Town, Western Cape, South Africa, 7700
      • MRC Unit on Child And Adolescent Health-Department of Paediatrics and child Health ( Site 2502)
• South Korea
  • Seoul, South Korea, 03080
    • Seoul National University Hospital ( Site 3203)
  • Seoul, South Korea, 03722
    • Severance Hospital Yonsei University Health System ( Site 3201)
  • Seoul, South Korea, 06351
    • Samsung Medical Center ( Site 3202)
  • Seoul, South Korea, 06591
    • The Catholic Univ. of Korea Seoul St. Mary's Hospital ( Site 3208)
  • Incheon
    • Bupyeong-gu, Incheon, South Korea, 21431
      • The Catholic University of Korea, Incheon St. Mary's Hospital ( Site 3209)
  • Jeonrabugdo
    • Jeonju, Jeonrabugdo, South Korea, 54907
      • Jeonbuk National University Hospital ( Site 3210)
  • Kyonggi-do
    • Ansan-si, Kyonggi-do, South Korea, 15355
      • Korea University Ansan Hospital ( Site 3212)
    • Anyang, Kyonggi-do, South Korea, 14068
      • Hallym University Sacred Heart Hospital ( Site 3207)
    • Seongnam, Kyonggi-do, South Korea, 13620
      • Seoul National University Bundang Hospital-Pediatrics ( Site 3204)
  • Pusan-Kwangyokshi
    • Busan, Pusan-Kwangyokshi, South Korea, 49241
      • Pusan National University Hospital ( Site 3206)
  • Seoul
    • Dongjak-gu, Seoul, South Korea, 06973
      • Chungang University Hospital ( Site 3211)
• Thailand
  • Chiang Mai, Thailand, 50200
    • Maharaj Nakorn Chiang Mai Hospital ( Site 3254)
  • Bangkok
    • Bangkok, Bangkok, Thailand, 10330
      • Chulalongkorn University-Pediatrics ( Site 3252)
    • Bangkok, Bangkok, Thailand, 10700
      • Siriraj Hospital ( Site 3251)
  • Changwat Khon Kaen
    • Muang, Changwat Khon Kaen, Thailand, 40002
      • Srinagarind Hospital. Khon Kaen University ( Site 3253)
  • Changwat Songkhla
    • Hat Yai, Changwat Songkhla, Thailand, 90110
      • Prince of Songkla University Faculty of Medicine ( Site 3255)
• Turkey (Türkiye)
  • Adana, Turkey (Türkiye), 01330
    • Cukurova Universitesi Tıp Fakultesi Balcalı Hastanesi ( Site 2555)
  • Ankara, Turkey (Türkiye), 06560
    • Gazi Universitesi Saglık Arastırma ve Uygulama Merkezi ( Site 2552)
  • Ankara, Turkey (Türkiye), 06590
    • Ankara Universitesi Tip Fakultesi Cebeci Hastanesi ( Site 2551)
  • Izmir, Turkey (Türkiye), 35100
    • Ege University Medical Faculty ( Site 2553)
  • Kayseri, Turkey (Türkiye), 38039
    • Erciyes University Medical Faculty-pediatric infection ( Site 2554)
• United Kingdom
  • Liverpool, United Kingdom, L12 2AP
    • Alder Hey Childrens NHS Foundation Trust Hospital ( Site 2606)
  • Bristol, City of
    • Bristol, Bristol, City of, United Kingdom, BS2 8AE
      • UH Bristol Education Centre ( Site 2607)
  • London, City of
    • London, London, City of, United Kingdom, SW17 0QT
      • St. Georges University Hospital NHS Foundation Trust ( Site 2601)
  • Northern Ireland
    • Belfast, Northern Ireland, United Kingdom, BT12 6BB
      • Royal Maternity Hospital ( Site 2602)
  • Oxfordshire
    • Oxford, Oxfordshire, United Kingdom, OX3 9DU
      • Oxford University Hospital NHS Foundation Trust ( Site 2604)
• United States
  • Alabama
    • Dothan, Alabama, United States, 36303
      • Southeastern Pediatric Associates, P.A. ( Site 0008)
  • Arkansas
    • Fayetteville, Arkansas, United States, 72703
      • Northwest Arkansas Pediatric Clinic ( Site 0050)
    • Jonesboro, Arkansas, United States, 72401
      • Children's Clinic of Jonesboro, PA ( Site 0058)
  • California
    • Long Beach, California, United States, 90806
      • Long Beach Memorial Medical Center ( Site 0014)
    • Madera, California, United States, 93637
      • Madera Family Medical Group ( Site 0046)
    • Ontario, California, United States, 91762
      • Orange County Research Institute ( Site 0057)
  • Colorado
    • Aurora, Colorado, United States, 80045
      • Children's Hospital Colorado ( Site 0066)
    • Colorado Springs, Colorado, United States, 80922
      • Optumcare Colorado Springs, LLC ( Site 0022)
  • District of Columbia
    • Washington D.C., District of Columbia, United States, 20010
      • Children's National Hospital ( Site 0076)
    • Washington D.C., District of Columbia, United States, 20016
      • MedStar Georgetown Pediatrics ( Site 0047)
  • Florida
    • Homestead, Florida, United States, 33030
      • Next Phase Research Alliance, LLC ( Site 0071)
    • Miami, Florida, United States, 33142
      • Acevedo Clinical Research Associates ( Site 0002)
  • Georgia
    • Chamblee, Georgia, United States, 30341
      • Tekton Research ( Site 0080)
    • Macon, Georgia, United States, 31210
      • Meridian Clinical Research, LLC ( Site 0083)
  • Idaho
    • Idaho Falls, Idaho, United States, 83404
      • Clinical Research Prime ( Site 0075)
    • Nampa, Idaho, United States, 83686
      • Saltzer Medical Group ( Site 0004)
  • Kansas
    • Topeka, Kansas, United States, 66604
      • Cotton-O'Neil Clinical Research Center PediatricCare ( Site 0061)
  • Louisiana
    • Haughton, Louisiana, United States, 71037
      • ACC Pediatric Research ( Site 0067)
  • Nebraska
    • Hastings, Nebraska, United States, 68901
      • Meridian Clinical Research, LLC ( Site 0082)
    • Lincoln, Nebraska, United States, 68504
      • Midwest Children's Health Research Institute, LLC ( Site 0044)
  • New Hampshire
    • Lebanon, New Hampshire, United States, 03756
      • Dartmouth-Hitchcock Medical Center ( Site 0031)
  • New Jersey
    • New Brunswick, New Jersey, United States, 08901
      • Rutgers University-Pediatric Clinical Research Center ( Site 0055)
  • North Carolina
    • Winston-Salem, North Carolina, United States, 27103
      • Javara - Wake Forest Health Network - Ford, Simpson, Lively & Rice Pediatrics ( Site 0093)
  • Ohio
    • Cleveland, Ohio, United States, 44121
      • Senders Pediatrics ( Site 0062)
    • Dayton, Ohio, United States, 45414
      • Ohio Pediatric Research Association ( Site 0063)
  • Pennsylvania
    • Hermitage, Pennsylvania, United States, 16148
      • CCP- Kid's Way ( Site 0017)
    • Pittsburgh, Pennsylvania, United States, 15213
      • UPMC Children's Hospital of Pittsburgh - Primary Care Center - Oakland ( Site 0043)
  • South Carolina
    • Charleston, South Carolina, United States, 29414
      • Coastal Pediatric Research ( Site 0013)
    • Greenville, South Carolina, United States, 29607
      • Tribe Clinical Research, LLC ( Site 0015)
  • Tennessee
    • Kingsport, Tennessee, United States, 37660
      • Holston Medical Group ( Site 0040)
  • Texas
    • Frisco, Texas, United States, 75035
      • Javara - Privia Medical Group North Texas - Frisco ( Site 0086)
    • Galveston, Texas, United States, 77555
      • University of Texas Medical Branch at Galveston ( Site 0059)
    • Houston, Texas, United States, 77065
      • DM Clinical Research ( Site 0005)
    • Lampasas, Texas, United States, 76550
      • FMC Science - Lampasas ( Site 0011)
    • Longview, Texas, United States, 75605
      • DCOL Center for Clinical Research ( Site 0042)
    • San Antonio, Texas, United States, 78229
      • University Health System- San Antonio ( Site 0048)
    • San Antonio, Texas, United States, 78244
      • Private Practice - Dr. Etokhana ( Site 0089)
    • San Antonio, Texas, United States, 78249
      • Road Runner Research, Ltd ( Site 0049)
  • Utah
    • Kaysville, Utah, United States, 84037
      • Alliance for Multispecialty Research, LLC ( Site 0092)
    • Layton, Utah, United States, 84041
      • Wee Care Pediatrics ( Site 0077)
    • Murray, Utah, United States, 84107
      • Cottonwood Pediatrics ( Site 0032)
    • Roy, Utah, United States, 84067
      • Wee Care Pediatrics-Roy ( Site 0053)
    • Salt Lake City, Utah, United States, 84108
      • University of Utah School of Medicine ( Site 0006)
    • South Jordan, Utah, United States, 84095
      • Copperview Medical Center ( Site 0078)
    • Syracuse, Utah, United States, 84075
      • Wee Care Pediatrics ( Site 0065)
  • Virginia
    • Charlottesville, Virginia, United States, 22902
      • Pediatric Research of Charlottesville, LLC ( Site 0073)
  • Washington
    • Cheney, Washington, United States, 99004
      • MultiCare Rockwood Cheney Clinic ( Site 0068)
    • Spokane, Washington, United States, 99202
      • Multicare Health System Institute for Research and Innovation ( Site 0025)
    • Tacoma, Washington, United States, 98405
      • Multicare Institute For Research And Innovation ( Site 0045)
  • West Virginia
    • Huntington, West Virginia, United States, 25701
      • Marshall University School of Medicine and Medical Center ( Site 0064)
  • Wisconsin
    • Marshfield, Wisconsin, United States, 54449
      • Marshfield Clinic ( Site 0054)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: No older than 1 year (Child)
• Accepts Healthy Volunteers: Yes

Description

Key Inclusion Criteria:

• Is a healthy male or female who is an early or moderate pre-term infant (≥29 to 34 weeks and 6 days gestational age) or a late pre-term or full-term infant (≥35 weeks gestational age)
• For the phase 2b cohort only: Has a chronological age >2 weeks of age up to 1 year and is entering their first respiratory syncytial virus (RSV) season at the time of obtaining documented informed consent.
• For the phase 3 cohort only: Has a chronological age from birth up to 1 year and is entering their first RSV season at the time of obtaining documented informed consent.
• For participants in South Korea only: Weighs ≥2 kg

Key Exclusion Criteria:

• Is recommended to receive palivizumab per local guidelines or professional society recommendations.
• Has known hypersensitivity to any component of clesrovimab
• Has a bleeding disorder contraindicating IM administration
• Has had a recent illness with rectal temperature ≥100.5°F (≥38.1°C) or axillary temperature ≥100.0°F (≥37.8°C) within 72 hours predose
• Has received any vaccine or monoclonal antibody for the prevention of RSV
• Is currently participating in or has participated in an interventional clinical study with an investigational compound or device at any time before first dose administration or while participating in this study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Clesrovimab 105 mg; Participants receive a single intramuscular (IM) administration of clesrovimab 105 mg on Day 1. An eligible subset of participants from RSV Season 1 will enter RSV season 2.	Biological: Clesrovimab; Clesrovimab solution; Other Names: MK-1654
Placebo Comparator: Placebo; Participants receive a single IM administration of placebo on Day 1. An eligible subset of participants from RSV Season 1 will enter RSV season 2.	Drug: Placebo; Placebo (0.9% sodium chloride [NaCL]) solution

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
RSV Season 1: Number of Participants With Respiratory Syncytial Virus (RSV)-Associated Medically Attended Lower Respiratory Infection (MALRI)	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 sample. Per protocol, the participants with outpatient and inpatient RSV-associated MALRI were reported together for RSV season 1 participants.	From Day 1 (postdose) to Day 150
RSV Season 1: Percentage of Participants With Solicited Injection-Site Adverse Events (AEs)	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. Solicited injection-site AEs included redness/erythema, swelling, and pain/tenderness. Per protocol, the percentage of RSV season 1 participants with solicited injection-site AEs were reported.	From Day 1 (postdose) to Day 5
RSV Season 1: Percentage of Participants With Fever	Fever was defined as rectal temperature ≥102.2°F (≥39.0°C) or axillary temperature ≥101.7°F (≥38.7°C). Per protocol, the percentage of RSV season 1 participants with fever were reported.	From Day 1 (postdose) to Day 5
RSV Season 1: Percentage of Participants With Solicited Systemic AEs	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. Solicited systemic AEs included irritability, somnolence/drowsiness, and appetite lost. Per protocol, the percentage of RSV season 1 participants with solicited systemic AEs were reported.	From Day 1 (postdose) to Day 5
RSV Season 1: Percentage of Participants With Anaphylaxis/Hypersensitivity AE of Special Interest (AESI)	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. Anaphylaxis/Hypersensitivity AESI included anaphylaxis, angioedema, bronchospasm, drug hypersensitivity, dyspnea, hypersensitivity, dysphonia, and wheezing. Per protocol, the percentage of RSV season 1 participants with anaphylaxis/hypersensitivity AESI were reported.	From Day 1 (postdose) to Day 42
RSV Season 1: Percentage of Participants With Rash AESI	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 acute generalized exanthematous pustulosis, drug eruption, drug reaction with eosinophilia and systemic symptoms, erythema multiforme, generalized rash of exfoliative nature, Stevens-Johnson syndrome, toxic epidermal necrolysis, and urticaria. Per protocol, the percentage of RSV season 1 participants with rash AESI were reported.	From Day 1 (postdose) to Day 42
RSV Season 1: Percentage of Participants With ≥1 Nonserious AE	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. Per protocol, the percentage of RSV season 1 participants with ≥1 nonserious AE were reported.	From Day 1 (postdose) to Day 42
Percentage of Participants With Serious Adverse Events (SAEs)	An SAE was any untoward medical occurrence that results in death; is life-threatening; required inpatient hospitalization/prolongs existing hospitalization; results in persistent or significant disability/incapacity; is a congenital anomaly/birth defect; or other important medical event. Per protocol, the percentage of participants in RSV season 1 and RSV season 2 with SAEs were reported.	RSV Season 1: Day 1 to Day 365, RSV Season 2: Day 366 to Day 515

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
RSV Season 1: Number of Participants With RSV-Associated Hospitalization	RSV-associated hospitalization is defined as a hospital admission for respiratory illness and RSV-positive RT-PCR nasopharyngeal sample. Per protocol, the number of participants with RSV-associated hospitalization were reported for RSV season 1.	From Day 1 (postdose) to Day 150
RSV Season 1: Number of Participants With RSV-Associated MALRI	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 RT-PCR nasopharyngeal sample. Per protocol, participants with outpatient and inpatient RSV-associated MALRI were reported together for RSV season 1 participants.	From Day 1 (postdose) to Day 180

Collaborators and Investigators

• Sponsor: Merck Sharp & Dohme LLC
• Investigators: Study Director: Medical Director, Merck Sharp & Dohme LLC

Publications and helpful links

General Publications

• Ginsburg AS, Srikantiah P. Respiratory syncytial virus: promising progress against a leading cause of pneumonia. Lancet Glob Health. 2021 Dec;9(12):e1644-e1645. doi: 10.1016/S2214-109X(21)00455-1. Epub 2021 Nov 11. No abstract available.
• Zar HJ, Simoes EAF, Madhi SA, Ramilo O, Senders SD, Shepard JS, Laoprasopwattana K, Piedrahita J, Novoa JM, Vargas SL, Dionne M, Jackowska T, Liu E, Ishihara Y, Ikeda K, Zhang Y, Railkar RA, Lutkiewicz J, Vora KA, Zang X, Maas BM, Lee AW, Guerra A, Sinha A; CLEVER (MK-1654-004) Study Group. Clesrovimab for Prevention of RSV Disease in Healthy Infants. N Engl J Med. 2025 Oct 2;393(13):1292-1303. doi: 10.1056/NEJMoa2502984. Epub 2025 Sep 17.

Helpful Links

• Merck Clinical Trials Information
• Plain Language Summary

Study record dates

Study Major Dates

• Study Start (Actual): April 7, 2021
• Primary Completion (Actual): July 9, 2024
• Study Completion (Actual): July 9, 2024

Study Registration Dates

• First Submitted: February 22, 2021
• First Submitted That Met QC Criteria: February 22, 2021
• First Posted (Actual): February 23, 2021

Study Record Updates

• Last Update Posted (Actual): February 11, 2026
• Last Update Submitted That Met QC Criteria: January 23, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Infections; RNA Virus Infections; Virus Diseases; Pneumovirus Infections; Paramyxoviridae Infections; Mononegavirales Infections; Respiratory Syncytial Virus Infections; MK-1654
• Other Study ID Numbers: 1654-004; MK-1654-004 (Other Identifier: MSD); jRCT2051210019 (Registry Identifier: jRCT); PHRR210706-003684 (Registry Identifier: PHRR); 2020-002405-26 (EudraCT Number); 2022-500350-42-00 (Registry Identifier: EU CT); U1111-1275-5918 (Registry Identifier: UTN)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: http://engagezone.msd.com/doc/ProcedureAccessClinicalTrialData.pdf

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No