AzTrials
AzTrials

Clostridium Difficile InfectionPhase 3CloverNCT03090191

Clostridium Difficile Vaccine Efficacy Trial

A Phase 3 study testing Clostridium difficile vaccine in people with Clostridium Difficile Infection, run by Pfizer at 426 sites in 23 countries.

Completed

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

Official record
Search all trials

Trial summary

The Clover trial is evaluating an investigational vaccine that may help to prevent Clostridium difficile infection. Participants in the study are adults 50 years of age and older, who are at risk of developing Clostridium difficile infection. Read more about this study

Who is it for?
Ages 50 years and olderHealthy volunteers can take part
Conditions the study is for
Clostridium Difficile Infection
What is being tested?
Clostridium difficile vaccine
Type of treatment
Vaccines
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
17,535 participants
Where
426 sitesin 23 countries
Study dates
29 Mar 2017to 21 Dec 2021
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 50 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Evidence of a personally signed and dated informed consent document.
  • Willing and able to comply with study procedures.
  • Subjects with an increased risk of future contact with healthcare systems or subjects who have received systemic antibiotics in the previous 12 weeks.
  • Ability to be contacted by telephone during study participation.
  • Negative urine pregnancy test for female subjects of childbearing potential.

Who cannot join

  • Investigator site staff members directly involved in the conduct of the study and their family members, site staff members otherwise supervised by the investigator, or subjects who are Pfizer employees, including their family members, directly involved in the conduct of the study.
  • Participation in other studies involving investigational drug(s)/vaccine(s) within 28 days prior to study entry until 1 month after the third vaccination.
  • Previous administration of an investigational C difficile vaccine or C difficile mAb therapy.
  • Prior episode of CDI..
  • Receipt of blood products or immunoglobulins within 6 months before enrollment.
  • Subjects who may be unable to respond to vaccination due to:
Show all 19Show fewer
  • Metastatic malignancy; or
  • End-stage renal disease; or
  • Any serious medical disorder likely to be fatal within the next 12 months; or
  • Congenital or acquired immunodeficiency; or
  • Receipt of high dose systemic corticosteroids for 14 days within 28 days of enrollment; or
  • Receipt of chronic systemic treatment with other known immunosuppressant medications, or radiotherapy, within 6 months of enrollment.
  • Known infection with human immunodeficiency virus (HIV).
  • Any bleeding disorder or anticoagulant therapy that would contraindicate intramuscular injection.
  • Any contraindication to vaccination or vaccine components, including previous anaphylactic reaction to any vaccine or vaccine-related components.
  • Prior small- or large-bowel resection.
  • Any condition or treatment resulting in frequent diarrhea.
  • Other acute or chronic condition or abnormality that may increase the risk associated with study participation or IP administration or may interfere with interpretation of study results
  • Pregnant or breastfeeding female subjects; male subjects and female subjects who are sexually active and at risk for pregnancy and will not/cannot use 2 methods of contraception

Trial locations and contacts

426 sites in 23 countries.

426 sites in 23 countries

United States220 sites

  • New Mexico VA Healthcare System

    Albuquerque, New Mexico, 87108

  • Lehigh Valley Health Network/Network Office of Research and Innovation

    Allentown, Pennsylvania, 18103

  • Community Clinical Research Center

    Anderson, Indiana, 46011

  • VA Ann Arbor Healthcare System

    Ann Arbor, Michigan, 48105

  • Clinical Alliance for Research & Education - Infectious Diseases, LLC

    Annandale, Virginia, 22003

  • Luminis Health Anne Arundel Medical Center Infusion Center

    Annapolis, Maryland, 21401

  • Luminis Health Anne Arundel Medical Center

    Annapolis, Maryland, 21401

  • Luminis Health Research Institute: Research Office

    Annapolis, Maryland, 21401

  • North Alabama Research Center, LLC

    Athens, Alabama, 35611

  • Clinical Trial Center University of Colorado Denver, School of Medicine

    Aurora, Colorado, 80045

  • University of Colorado Clinical & Translational Research Center Clinic

    Aurora, Colorado, 80045

  • University of Colorado Clinical & Translational Research Center Outpatient Clinic

    Aurora, Colorado, 80045

  • University of Colorado Denver, School of Medicine

    Aurora, Colorado, 80045

  • University of Colorado Department of AIP 2. Pharmacy Bulk Storage

    Aurora, Colorado, 80045

  • Tekton Research, Inc.

    Austin, Texas, 78745

  • Kentucky Pediatric/Adult Research

    Bardstown, Kentucky, 40004

  • Bay Pines VA Healthcare System

    Bay Pines, Florida, 33744

  • Meridian Clinical Research LLC

    Binghamton, New York, 13901

  • Bozeman Health Deaconess Hospital d/b/a Bozeman Health Clinical Research

    Bozeman, Montana, 59715

  • Bozeman Health GI Clinic

    Bozeman, Montana, 59715

  • Florida Sleep Disorder Center of Brandon

    Brandon, Florida, 33511

  • Teradan Clinical Trials

    Brandon, Florida, 33511

  • Holston Medical Group

    Bristol, Tennessee, 37620

  • Internal Medicine and Pediatric Associates of Bristol, PC

    Bristol, Tennessee, 37620

  • PMG Research of Bristol, LLC

    Bristol, Tennessee, 37620

  • Mercury Street Medical Group, PLLC

    Butte, Montana, 59701

  • Capital Area Research, LLC

    Camp Hill, Pennsylvania, 17011

  • ClinSite, LLC

    Canton, Michigan, 48187

  • Aultman Cardiology Clinical Trials

    Canton, Ohio, 44710

  • Aultman Hospital

    Canton, Ohio, 44710

  • Infectious Disease of Indiana, PSC

    Carmel, Indiana, 46032

  • St. Vincent Outpatient Treatment Center

    Carmel, Indiana, 46032

  • PMG Research of Raleigh, LLC d/b/a PMG Research of Cary

    Cary, North Carolina, 27518

  • Christie Clinic, LLC

    Champaign, Illinois, 61822

  • Medical Research South, LLC

    Charleston, South Carolina, 29414

  • PMG Research of Charlotte, LLC

    Charlotte, North Carolina, 28209

  • Southeast Clinical Research

    Chiefland, Florida, 32626

  • UC Health Physicians Office Clifton

    Cincinnati, Ohio, 45219

  • University of Cincinnati Medical Center

    Cincinnati, Ohio, 45219

  • Sterling Research Group, Ltd.

    Cincinnati, Ohio, 45246

  • University Of Cincinnati-Internal Medicine Division of Digestive Diseases

    Cincinnati, Ohio, 45267

  • Innovative Research of West FL., Inc.

    Clearwater, Florida, 33756

  • Louis Stokes Cleveland VA Medical Center

    Cleveland, Ohio, 44106

  • University Hospitals Cleveland Medical Center

    Cleveland, Ohio, 44106

  • Velocity Clinical Research, Inc.

    Cleveland, Ohio, 44122

  • OhioHealth Riverside Methodist Hospital

    Columbus, Ohio, 43214

  • Riverside Methodist Hospital

    Columbus, Ohio, 43214

  • Remington-Davis, Incorporated

    Columbus, Ohio, 43215

  • Alliance for Multispecialty Reseach, LLC

    Coral Gables, Florida, 33134

  • California Kidney Specialist

    Covina, California, 91723

  • Usborne Family Medicine

    Covina, California, 91724

  • North Texas Infectious Diseases Consultants, P.A.

    Dallas, Texas, 75246

  • Synexus US, LP

    Dallas, Texas, 75324

  • Kaiser Permanente Daly City

    Daly City, California, 94015

  • PriMED Clinical Research

    Dayton, Ohio, 45419

  • Omega Research Consultants, LLC

    DeBary, Florida, 32713

  • Atlanta VA Medical Center

    Decatur, Georgia, 30033

  • Accel Research Sites - DeLand Clinical Research Unit

    DeLand, Florida, 32720

  • Premier Health Research Center, LLC

    Downey, California, 90241

  • J. Lewis Research Inc. / Foothill Family Clinic Draper

    Draper, Utah, 84020

  • Durham VAMC

    Durham, North Carolina, 27705

  • Duke Early Phase Clinical Research

    Durham, North Carolina, 27710

  • Duke University Hospital Investigational Drug Services (IDS) Pharmacy

    Durham, North Carolina, 27710

  • Velocity Clinical Research, Providence

    East Greenwich, Rhode Island, 02818

  • Meridian Clinical Research, LLC

    Endwell, New York, 13760

  • Westminster Family Medicine

    Erie, Pennsylvania, 16506

  • Liberty Family Practice

    Erie, Pennsylvania, 16508

  • Deaconess Clinic Mt. Pleasant

    Evansville, Indiana, 47725

  • Lillestol Research LLC

    Fargo, North Dakota, 58104

  • Fleming Island Center for Clinical Research

    Fleming Island, Florida, 32003

  • Aa Mrc Llc

    Flint, Michigan, 48504

  • Texas Health Care, PLLC

    Fort Worth, Texas, 76104

  • Ventavia Research Group, LLC

    Fort Worth, Texas, 76104

  • University of North Texas Health Science Center at Fort Worth

    Fort Worth, Texas, 76107

  • Malcom Randall VA Medical Center Investigational Drug Services

    Gainesville, Florida, 32608

  • Malcom Randall VA Medical Center

    Gainesville, Florida, 32608

  • University of Texas Medical Branch

    Galveston, Texas, 77555

  • PharmQuest

    Greensboro, North Carolina, 27408

  • MedPharmics

    Gulfport, Mississippi, 39503

  • Gastroenterology Center of Connecticut, PC

    Hamden, Connecticut, 06518

  • Medical Research Center of Connecticut, LLC

    Hamden, Connecticut, 06518

  • Indago Research & Health Center, Inc

    Hialeah, Florida, 33012

  • PMG Research of Hickory, LLC

    Hickory, North Carolina, 28601

  • ID Care

    Hillsborough, New Jersey, 08844

  • Edward Hines Jr VA Hospital

    Hines, Illinois, 60141

  • East-West Medical Research Institute

    Honolulu, Hawaii, 96814

  • Kelsey Research Foundation

    Houston, Texas, 77025

  • Kelsey-Seybold Clinic

    Houston, Texas, 77025

  • Texas Center for Drug Development, Inc.

    Houston, Texas, 77081

  • Medical Affiliated Research Center, Inc.

    Huntsville, Alabama, 35801

  • Snake River Research, PLLC

    Idaho Falls, Idaho, 83404

  • St. Vincent Hospital & Health Care Center

    Indianapolis, Indiana, 46260

  • St. Vincent Hospital and Health Care Center

    Indianapolis, Indiana, 46260

  • Clinical Neuroscience Solutions,Inc.

    Jacksonville, Florida, 32256

  • PMG Research, Inc. d/b/a PMG Research of Knoxville

    Knoxville, Tennessee, 37912

  • PMG Research,Inc. d/b/a PMG Research of Knoxville

    Knoxville, Tennessee, 37938

  • Paradigm Clinical Research Centers, Inc.

    La Mesa, California, 91942

  • Multi-Specialty Research Associates, Inc.

    Lake City, Florida, 32055

  • Central Kentucky Research Associates, LLC

    Lexington, Kentucky, 40509

  • Main Street Physician's Care - Waterway

    Little River, South Carolina, 29566

  • Baptist Health Center for Clinical Research

    Little Rock, Arkansas, 72205

  • Baptist Health Rehabilitation Institute

    Little Rock, Arkansas, 72205

  • VA Loma Linda Healthcare System Research Pharmacy

    Loma Linda, California, 92357

  • VA Loma Linda Healthcare System

    Loma Linda, California, 92357

  • Long Beach Clinical Trials Services, Inc.

    Long Beach, California, 90806

  • Long Beach Clinical Trials

    Long Beach, California, 90806

  • VA Long Beach Healthcare System

    Long Beach, California, 90822

  • Academic Medical Research Institute

    Los Angeles, California, 90022

  • Ronald Reagan UCLA Medical Center

    Los Angeles, California, 90095

  • UCLA CTRC Outpatient Unit

    Los Angeles, California, 90095

  • Tandem Clinical Research, LLC

    Marrero, Louisiana, 70072

  • Marshfield Medical Center - Marshfield

    Marshfield, Wisconsin, 54449

  • VA Northern California Health Care System

    Mather, California, 95655

  • Clinical Neuroscience Solutions, Inc.

    Memphis, Tennessee, 38119

  • Great Lakes Medical Research LLC

    Mentor, Ohio, 44060

  • Advanced Clinical Research

    Meridian, Idaho, 83642

  • Solaris Clinical Research

    Meridian, Idaho, 83646

  • Synexus US, dba Research Across America

    Mesquite, Texas, 75149

  • MedPharmics, LLC

    Metairie, Louisiana, 70006

  • Optimus U. Corp.

    Miami, Florida, 33125

  • Finlay Medical Research

    Miami, Florida, 33126

  • Doctors Research Institute

    Miami, Florida, 33135

  • Acevedo Clinical Research Associates

    Miami, Florida, 33142

  • Next Phase Research Alliance

    Miami, Florida, 33144

  • Charisma Medical and Research Center

    Miami Lakes, Florida, 33014

  • Ocean Blue Medical Research Center, Inc.

    Miami Springs, Florida, 33166

  • Virginia Research Center LLC

    Midlothian, Virginia, 23114

  • Clinical Research Consulting, LLC

    Milford, Connecticut, 06460

  • MOC Research

    Mishawaka, Indiana, 46544

  • Coastal Clinical Research, LLC, An AMR Company

    Mobile, Alabama, 36608

  • Barnum Medical Research Inc

    Natchitoches, Louisiana, 71457

  • Ochsner Center for Primary Care and Wellness

    New Orleans, Louisiana, 70121

  • Ochsner Clinic Foundation

    New Orleans, Louisiana, 70121

  • Meridian Clinical Research, LLC

    Norfolk, Nebraska, 68701

  • Coastal Carolina Research Center

    North Charleston, South Carolina, 29405

  • Arkansas Gastroenterology

    North Little Rock, Arkansas, 72117

  • IPS Research Company

    Oklahoma City, Oklahoma, 73103

  • Barrett Clinic

    Omaha, Nebraska, 68128

  • Meridian Clinical Research, LLC

    Omaha, Nebraska, 68134

  • Clinical Neuroscience Solutions, Inc. dba CNS Healthcare

    Orlando, Florida, 32801

  • HMD Research LLC

    Orlando, Florida, 32819

  • Veterans Affairs Palo Alto Health Care System

    Palo Alto, California, 94304

  • LinQ Research, LLC

    Pearland, Texas, 77584

  • Pines Care Research Center, LLC

    Pembroke Pines, Florida, 33026

  • The Pain Center of Arizona

    Peoria, Arizona, 85381

  • Drexel University College of Medicine

    Philadelphia, Pennsylvania, 19102

  • Phoenix VA Health Care System

    Phoenix, Arizona, 85012

  • Phoenix Clinical LLC

    Phoenix, Arizona, 85014

  • MedPharmics, LLC

    Phoenix, Arizona, 85015

  • Hope Research Institute

    Phoenix, Arizona, 85018

  • The Pain Center of Arizona

    Phoenix, Arizona, 85018

  • VA Pittsburgh Healthcare System

    Pittsburgh, Pennsylvania, 15240

  • Preferred Primary Care Physicians, Inc.

    Pittsburgh, Pennsylvania, 15243

  • Progressive Medical Research

    Port Orange, Florida, 32127

  • Frandsen Family Medicine DBA Sound Medical Research

    Port Orchard, Washington, 98366

  • Kaiser Permanente Center For Health Research

    Portland, Oregon, 97227

  • Columbia Research Group, Inc.

    Portland, Oregon, 97239

  • VA Portland Healthcare System

    Portland, Oregon, 97239

  • PMG Research of Raleigh, LLC

    Raleigh, North Carolina, 27609

  • Wake Research Associates, LLC

    Raleigh, North Carolina, 27612

  • Covigilant Research, LLC

    Rancho Mirage, California, 92270

  • Amici Clinical Research

    Raritan, New Jersey, 08869

  • Paradigm Clinical Research Centers, Inc.

    Redding, California, 96001

  • VA Loma Linda Healthcare System Ambulatory Care System

    Redlands, California, 92373

  • Covigilant Research LLC

    Riverside, California, 92506

  • Advanced Clinical Research/Gut Whisperer

    Riverton, Utah, 84065

  • Mayo Clinic Rochester, Methodist Hospital Campus

    Rochester, Minnesota, 55902

  • Mayo Clinic

    Rochester, Minnesota, 55905

  • Rochester Clinical Research

    Rochester, New York, 14609

  • PMG Research of Rocky Mount, LLC

    Rocky Mount, North Carolina, 27804

  • Kaiser Permanente Roseville

    Roseville, California, 95661

  • One Community Health

    Sacramento, California, 95811

  • Kaiser Permanente Sacramento

    Sacramento, California, 95815

  • CTSC Clinical Research Center

    Sacramento, California, 95817

  • Lawrence J. Ellison Ambulatory Care Center

    Sacramento, California, 95817

  • University of California, Davis Medical Center

    Sacramento, California, 95817

  • Kaiser Permanente South Sacramento

    Sacramento, California, 95823

  • Salem VAMC

    Salem, Virginia, 24153

  • PMG Research of Salisbury, LLC

    Salisbury, North Carolina, 28144

  • J. Lewis Research, Inc./Foothill Family Clinic

    Salt Lake City, Utah, 84109

  • J Lewis Research, Incorporated

    Salt Lake City, Utah, 84121

  • Clinical Trials of Texas, Inc.

    San Antonio, Texas, 78229

  • Diagnostics Research Group

    San Antonio, Texas, 78229

  • South Texas Veterans Healthcare System, Audie L Murphy Hospital

    San Antonio, Texas, 78229

  • Breakthrough Clinical Trials

    San Bernardino, California, 92408

  • VA San Diego Healthcare System

    San Diego, California, 92161

  • California Kidney Specialists

    San Dimas, California, 91773

  • Kaiser Permanente San Jose

    San Jose, California, 95119

  • Kaiser Permanente Santa Clara

    Santa Clara, California, 95051

  • Meridian Clinical Research

    Savannah, Georgia, 31406

  • Alta California Medical Group

    Simi Valley, California, 93065

  • Meridian Clinical Research

    Sioux City, Iowa, 51106

  • South Jersey Infectious Disease

    Somers Point, New Jersey, 08244

  • J. Lewis Research, Inc. - Jordan River Family Medicine

    South Jordan, Utah, 84095

  • Springfield Clinic Infectious Diseases

    Springfield, Illinois, 62702

  • Center for Outpatient Health

    St Louis, Missouri, 63108

  • Washington University School of Medicine

    St Louis, Missouri, 63110-1093

  • Barnes Jewish Hospital

    St Louis, Missouri, 63110

  • Barnes-Jewish Hospital

    St Louis, Missouri, 63110

  • Center for Advanced Medicine

    St Louis, Missouri, 63110

  • Center For Clinical Studies

    St Louis, Missouri, 63110

  • Sundance Clinical Research

    St Louis, Missouri, 63141

  • Revival Research Institute, LLC

    Sterling Heights, Michigan, 48313

  • Clinical Research Atlanta

    Stockbridge, Georgia, 30281

  • Precision Clinical Research, LLC

    Sunrise, Florida, 33351

  • Clinical Research Institute of Arizona, LLC

    Surprise, Arizona, 85374

  • Waterway Primary Care LLC DBA Tabor City Family Medicine

    Tabor City, North Carolina, 28463

  • MultiCare Institute for Research & Innovation

    Tacoma, Washington, 98405

  • Universal Research Group, LLC

    Tacoma, Washington, 98405

  • DM Clinical Research

    Tomball, Texas, 77375

  • Martin Diagnostic Clinic

    Tomball, Texas, 77375

  • Trinity Clinical Research

    Tullahoma, Tennessee, 37388

  • Preferred Primary Care Physicians, Inc.

    Uniontown, Pennsylvania, 15401

  • Kaiser Permanente Walnut Creek

    Walnut Creek, California, 94596

  • Wenatchee Valley Hospital & Clinics

    Wenatchee, Washington, 98801

  • Soma Medical Center

    West Palm Beach, Florida, 33406

  • Alliance for Multispecialty Research, LLC

    Wichita, Kansas, 67205

  • PMG Research of Wilmington, LLC

    Wilmington, North Carolina, 28401

  • PMG Research of Winston-Salem, LLC

    Winston-Salem, North Carolina, 27103

  • Progressive Medicine of the Triad, LLC

    Winston-Salem, North Carolina, 27103

Other trials in United States

Japan25 sites

  • Juntendo University Hospital

    Bunkyo-ku, Tokyo, 113-8431

  • Fukuwa Clinic

    Chuo-ku, Tokyo, 104-0031

  • Nozaki Tokushukai Hospital

    Daitō, Osaka, 547-0074

  • Fukui-Ken Saiseikai Hospital

    Fukui, 918-8503

  • Fukuyama City Hospital

    Fukuyama, Hiroshima, 721-8511

  • Iizuka Hospital

    Iizuka, Fukuoka, 820-8505

  • Seishinkai Inoue Hospital

    Itoshima, Fukuoka, 819-1104

  • Fukuoka Tokushukai Hospital

    Kasuga, Fukuoka, 816-0864

  • Tokai Memorial Hospital

    Kasugai, Aichi-ken, 487-0031

  • Kenwakai Otemachi Hospital

    Kitakyushu, Fukuoka, 803-8543

  • Medical Corporation Tokushukai Koga General Hospital

    Koga, Ibaraki, 306-0041

  • Japanese Red Cross Kumamoto Hospital

    Kumamoto, 861-8520

  • Omi Medical Center

    Kusatsu, Shiga, 525-8585

  • Social Medical Care Corporation Hose-kai Marunouchi Hospital

    Matsumoto, Nagano, 390-8601

  • Mito Kyodo General Hospital

    Mito, Ibaraki, 310-0015

  • Aichi Medical University Hospital

    Nagakute, Aichi-ken, 480-1195

  • Daido Clinic

    Nagoya, Aichi-ken, 457-8511

  • Kamiiida daiichi General Hospital

    Nagoya, Aichi-ken, 462-0802

  • Nerima General Hospital

    Nerima-ku, Tokyo, 176-8530

  • Osaki Citizen Hospital

    Ōsaki, Miyagi, 989-6183

  • Saga-Ken Medical Centre Koseikan

    Saga, 840-8571

  • Miyanomori Memorial Hospital

    Sapporo, Hokkaido, 064-8570

  • Sekino Hospital

    Toshima-ku, Tokyo, 171-0014

  • Yaizu City Hospital

    Yaizu, Shizuoka, 425-8505

  • Yokosuka Kyosai Hospital

    Yokosuka, Kanagawa, 238-8558

Other trials in Japan

Bulgaria17 sites

  • "MHAT- Dr. Hristo Stambolski" EOOD

    Kazanlak, 6100

  • MHAT ''Sv.Ivan Rilski-Kozloduy'' EOOD; Internal Department

    Kozloduy, 3320

  • MHAT "Sv. Nikolay Chudotvorets" EOOD

    Lom, 3600

  • UMHAT "Dr. Georgi Stranski" EAD, Second Psychiatric Clinic of general psychiatry and dependence

    Pleven, 5800

  • UMHAT "Sveti Georgi" EAD

    Plovdiv, 4002

  • "Center for Mental Health - Ruse" EOOD

    Rousse, 7000

  • SHATPPD Dr. Dimitar Gramatikov - Ruse EOOD

    Rousse, 7002

  • ''Medical Center-1-Sevlievo'' EOOD

    Sevlievo, 5400

  • MHAT -Silistra AD

    Silistra, 7500

  • MC ''Tsaritsa Yoanna''EOOD

    Sliven, 8800

  • MC 'Cardiohelp' EOOD

    Sofia, 1142

  • "Acibadem City Clinic University Hospital" EOOD

    Sofia, 1407

  • Acibadem City Clinic Tokuda Ead

    Sofia, 1407

  • MHAT "Sveta Anna - Sofia" AD, Clinic of Internal Diseases

    Sofia, 1750

  • "SHATPD-Troyan" EOOD

    Troyan Municipality, 5600

  • MC Medica Plus OOD

    Veliko Tarnovo, 5000

  • MHAT ''Sveta Petka" AD

    Vidin, 3700

Other trials in Bulgaria

Slovakia13 sites

  • PULMO-MEDIK s.r.o., Pneumologicko-ftizeologicka ambulancia

    Bojnice, 972 01

  • Medak s.r.o., Gastroenterologicka ambulancia

    Bratislava, 851 01

  • Stalerg, s.r.o.

    Košice, 040 22

  • KM Management spol. s.r.o., Gastroenterologicke a hepatologicke centrum Nitra

    Nitra, 949 01

  • Dionea, s.r.o.

    Nové Zámky, 940 01

  • MEDIPA, s.r.o.

    Piešťany, 921 01

  • MUDr. Viliam Cibik, PhD, s.r.o.

    Pruské, 01852

  • Medilex s.r.o., Interna ambulancia

    Rimavská Sobota, 979 01

  • Plucna ambulancia Hrebenar s.r.o.

    Spišská Nová Ves, 052 01

  • SPAOLO s.r.o., Ambulancia vnutorneho lekarstva

    Stará Turá, 916 01

  • Privatna urologicka ambulancia, s.r.o.

    Trenčín, 911 01

  • MUDr. Zakova, s.r.o.

    Trenčín, 91101

  • Fakutna nemocnica Trnava

    Trnava, 917 75

Other trials in Slovakia

South Korea13 sites

  • Korea University Ansan Hospital

    Ansan, Gyeonggi-do, 15355

  • Dong-A University Hospital

    Busan, 49201

  • Kyungpook National University Hospital

    Daegu, 41944

  • The Catholic University of Korea, St. Vincent's Hospital

    Gyeonggi-do, 16247

  • Gachon University Gil Medical Center

    Incheon, 21565

  • Inha University Hospital

    Incheon, 22332

  • Korea University Anam Hospital

    Seoul, 02841

  • Hallym University Kangdong Sacred Heart Hospital

    Seoul, 05355

  • Samsung Medical Center

    Seoul, 06351

  • Hallym University Kangnam Sacred Heart Hospital

    Seoul, 07441

  • Korea University Guro Hospital

    Seoul, 08308

  • Asan Medical Center

    Songpa-gu, Seoul, 05505

  • Yonsei University Wonju Severance Christian Hospital

    Wŏnju, Gangwon-do, 26426

Other trials in South Korea

United Kingdom13 sites

  • Heart of England NHS Foundation Trust

    Birmingham, WEST Midlands, B9 5SS

  • Layton Medical Centre

    Blackpool, Lancashire, FY3 7EN

  • NHS Lothian, Western General Hospital

    Edinburgh, Midlothian, EH4 2XU

  • Royal Devon & Exeter Hospital

    Exeter, Devon, EX2 5DW

  • Fowey River Practice

    Fowey, Cornwall, PL23 1DT

  • St James University Hospital

    Leeds, LS9 7TF

  • University Hospitals of Leicester NHS Trust

    Leicester, Leicestershire, LE1 5WW

  • Oak Tree Surgery

    Liskeard, Cornwall, PL14 3XA

  • Newcastle upon Tyne Hospitals NHS Foundation trust

    Newcastle upon Tyne, NE1 4LP

  • The Alverton Practise, St Clare Medical Centre

    Penzance, Cornwall, TR183DX

  • Knowle House Surgery

    Plymouth, Devon, PL5 3JB

  • Stockport Nhs Foundation Trust

    Stockport, Cheshire, SK27JE

  • Rame Group Practice, Rame Medical Ltd.

    Torpoint, Cornwall, PL11 2TB

Other trials in United Kingdom

Australia12 sites

  • Eastern Health - Box Hill Hospital

    Box Hill, Victoria, 3128

  • Emeritus Research

    Camberwell, Victoria, 3124

  • Barwon Health

    Geelong, Victoria, 3220

  • Paratus Clinical Pty Ltd

    Kanwal, New South Wales, 2259

  • Australian Clinical Research Network

    Maroiubra, New South Wales, 2035

  • Maroubra Medical Centre

    Maroubra, New South Wales, 2035

  • Australian Clinical Research Network

    Maroubra, 2035

  • Linear Clinical Research

    Nedlands, Western Australia, 6009

  • Austrials Pty Ltd

    Sherwood, Queensland, 4075

  • Mater Misericordiae Ltd & Mater Medical Research Institute Ltd

    South Brisbane, Queensland, 4101

  • University Clinic Pharmacy

    Westmead, New South Wales, 2145

  • Westmead Hospital

    Westmead, New South Wales, 2145

Other trials in Australia

Canada12 sites

  • Intermed Groupe Santé

    Chicoutimi, Quebec, G7H 7Y8

  • Q & T Research Outaouais Inc.

    Gatineau, Quebec, J8Y 6S8

  • Centre Integre de Sante et de Services Sociaux de la Monteregie- Center- Hopital Charles LeMoyne

    Greenfield Park, Quebec, J4V 2H1

  • The Ottawa Hospital General Campus

    Ottawa, Ontario, K1H 8L6

  • The Ottawa Hospital Civic Campus

    Ottawa, Ontario, K1Y 4E9

  • Centre de recherche du CHU de Quebec-Universite Laval

    Québec, Quebec, G1E7G9

  • Centre de recherche Saint-Louis

    Québec, Quebec, G1W 4R4

  • ALPHA Recherche Clinique

    Québec, Quebec, G3K 2P8

  • CIUSSS de l'Estrie - CHUS

    Sherbrooke, Quebec, J1H5N4

  • Manna Research Inc. (Toronto)

    Toronto, Ontario, M9W4L6

  • Centre Integre Universitaire de Santé et de Services Sociaux de la Mauricie et du Centre du Québec

    Trois-Rivières, Quebec, G8Z 3R9

  • Vancouver Coastal Health Research Institution-clinical research unit-Diamond Health Care Centre

    Vancouver, British Columbia, V5Z1M9

Other trials in Canada

Spain12 sites

  • Complejo Hospitalario Universitario A Coruna

    A Coruña, 15006

  • Parc de Salut Mar- Hospital del Mar

    Barcelona, 08003

  • Hospital Clinic de Barcelona

    Barcelona, 08036

  • Hospital de la Santa Creu i Sant Pau

    Barcelona, 08041

  • EAP Centelles

    Centelles, Barcelona, 08540

  • Hospital Universitari de Bellvitge

    L'Hospitalet de Llobregat, Barcelona, 08907

  • Hospital Universitario de la Princesa

    Madrid, 28006

  • Hospital Universitario Gregorio Marañón

    Madrid, 28007

  • Hospital Universitario Ramon y Cajal

    Madrid, 28034

  • Hospital Universitario Fundacion Jimenez Diaz

    Madrid, 28040

  • Hospital Universitario Virgen Macarena

    Seville, 41009

  • Hospital Universitari i Politecnic La Fe

    Valencia, 46026

Other trials in Spain

Czechia11 sites

  • Ordinace vseobecneho praktickeho lekare

    Benátky nad Jizerou, 29471

  • Doktor Brno s.r.o.

    Brno, Czech, 65622

  • Nemocnice Kyjov, prispevkova organizace, Infekcni oddeleni

    Kyjov, 697 01

  • Slezska Nemocnice v Opave, prispevkova organizace

    Opava, 74601

  • Policska nemocnice s.r.o.,

    Polička, 572 01

  • Fakultni nemocnice v Motole

    Prague, 15006

  • Oblastni nemocnice Pribram, a.s.

    Pribram I., 26101

  • Interna a kardiologie s.r.o.

    Rožnov pod Radhoštěm, 756 61

  • Nemocnice Slany, p.o.

    Slaný, 274 01

  • Sarkamed s.r.o.

    Slaný, 27401

  • Krajska zdravotni, a.s., Masarykova nemocnice Usti nad Labem

    Ústí nad Labem, 401 13

Other trials in Czechia

Germany11 sites

  • Emovis GmbH

    Berlin, 10629

  • MECS Cottbus GmbH

    Cottbus, 03050

  • Diabetologische Gemeinschaftspraxis Dr. Schaper & Dr. Faulmann

    Dresden, 01279

  • Universitaetsklinikum Essen, Klinik fuer Infektiologie

    Essen, 45147

  • EUGASTRO GmbH/ Praxis

    Leipzig, 04103

  • SIBAmed Studienzentrum GmbH & Co.KG

    Leipzig, 04103

  • Gemeinschaftspraxis Dr. med. Heidrun Taeschner und Dr. med. Susanne Bonigut

    Leipzig, 04249

  • Universitaetsmedizin Rostock

    Rostock, 18057

  • Praxis Dr. med. J. Springub/ W. Schwarz

    Westerstede, 26655

  • Studienzentrum Nordwest

    Westerstede, 26655

  • Klinikum Wuerzburg Mitte gGmbH

    Würzburg, 97070

Other trials in Germany

Colombia10 sites

  • Fundación Cardiomet CEQUIN

    Armenia, Quindío Department, 630004

  • Clinica de la Costa Ltda.

    Barranquilla, Atlántico, 080020

  • Centro de Investigaciones - MedPlus Centro de Recuperación Integral S.A.S.

    Bogotá, D.C., 110221

  • Fundacion Valle del Lili

    Cali, Valle del Cauca Department, 760032

  • Centro Medico Imbanaco de Cali S.A.

    Cali, Valle del Cauca Department, 760043

  • Fundacion Cardiovascular de Colombia

    Floridablanca, Santander Department, 681002

  • Asociación IPS Médicos Internistas de Caldas

    Manizales, Caldas Department, 170004

  • Hospital Pablo Tobon Uribe

    Medellín, Antioquia, 050001

  • Fundacion Centro de Investigacion Clinica - CIC

    Medellín, Antioquia, 050021

  • Instituto de Coloproctologia ICO

    Medellín, Antioquia, 050025

Other trials in Colombia

Hungary9 sites

  • Bajai Szent Rokus Korhaz, II Belgyogyaszat

    Baja, 6500

  • DRC Kft.

    Balatonfüred, 8230

  • Budapesti Szent Ferenc Korhaz, Kardiologiai Rehabilitacios Osztaly

    Budapest, 1021

  • Del-pesti Centrumkorhaz - Orszagos Hematologiai es Infektologiai Intezet, I. Belgyogyaszati Osztaly

    Budapest, 1097

  • Orszagos Koranyi Pulmonologiai Intezet, VI. Osztaly

    Budapest, 1121

  • Semmelweis Egyetem III. Sz. Belgyogyaszati Klinika

    Budapest, 1125

  • ClinTrial Audit Kft., Klinikai Farmakologiai Intezet, Vedooltasi Ambulancia

    Debrecen, 4031

  • CRU Hungary Kft.

    Encs, 3860

  • Somogy Megyei Kaposi Mor Oktato Korhaz, Infektologiai Osztaly

    Kaposvár, 7400

Other trials in Hungary

Poland8 sites

  • NZOZ Vitamed

    Bydgoszcz, 85-079

  • Synexus Polska Sp. z o.o Oddzial w Gdansku

    Gdansk, 80-382

  • Synexus Polska Sp. z o.o. Oddzial w Gdyni

    Gdynia, 81-537

  • SYNEXUS Polska Sp. z o.o. Oddzial w Katowicach

    Katowice, 40-040

  • Niepubliczny Zaklad Opieki Zdrowotnej Salmed S. C.

    Łęczna, 21-010

  • Synexus Polska Sp. z o.o. Oddział w Poznaniu

    Poznan, 60-702

  • Synexus Polska Sp. z o.o. Oddzial w Warszawie

    Warsaw, 01-192

  • Synexus Polska Sp. z o.o. Oddzial we Wroclawiu

    Wroclaw, 50-381

Other trials in Poland

Finland6 sites

  • Helsinki University Central Hospital

    Helsinki, 00029 HUS

  • Kokkola Vaccine Research Clinic

    Kokkola, 67100

  • Oulu Vaccine Research Clinic

    Oulu, 90220

  • Pori Vaccine Research Clinic

    Pori, 28100

  • Tampere Vaccine Research Clinic

    Tampere, 33100

  • Turku Vaccine Research Clinic

    Turku, 20520

Other trials in Finland

Argentina5 sites

  • Hospital Aleman

    C.a.b.a., Buenos Aires, C1118AAT

  • Hospital Italiano de Buenos Aires

    C.a.b.a., Buenos Aires, C1199ABB

  • Centro Médico Dra. De Salvo

    C.a.b.a., Buenos Aires, C1426ABP

  • Hospital Nuestra Senora de la Misericordia

    Córdoba, X5000JRD

  • Sanatorio Británico S.A.

    Rosario, Santa Fe Province, S2000CVB

Other trials in Argentina

Chile5 sites

  • Psicomed Esudios Medicos

    Antofagasta, Antofagasta, 1270244

  • Biomedica Research Group

    Santiago, Santiago Metropolitan, 7500710

  • Fundacion Arriaran

    Santiago, Santiago Metropolitan, 8360159

  • Hospital Dr. Hernan Henriquez Aravena

    Temuco, Araucania, 4781151

  • Centro de Investigacion Clínica del Sur

    Temuco, IX Region de LA Araucania, 4781156

Other trials in Chile

Portugal5 sites

  • Hospital Garcia de Orta

    Almada, 2805-267

  • Centro Hospitalar do Baixo Vouga, E.P.E.

    Aveiro, 3814-501

  • Hospital de Braga

    Braga, 4710-243

  • Hospital Senhora de Oliveira - Guimaraes, E.P.E.

    Guimarães, 4835-044

  • Centro Hospitalar Vila Nova de Gaia/Espinho, E.P.E.

    Vila Nova de Gaia, 4434-502

Other trials in Portugal

Sweden5 sites

  • Infektionskliniken, Malarsjukhuset

    Eskilstuna, 63188

  • Gothia Forum CTC/Sahlgrenska Universitetssjukhuset

    Gothenburg, 41345

  • Sahlgrenska Universitetssjukhuset - Ostra Sjukhuset

    Gothenburg, 41650

  • Avdelningen for kliniska provningar, S-huset

    Örebro, 70362

  • Karolinska Trial Alliance, KTA Prim Sabbatsbergs sjukhus

    Stockholm, 11324

Other trials in Sweden

France4 sites

  • CHU DIJON BOURGOGNE- Hopital Francois Mitterrand

    Dijon, 21079

  • CIC Vaccinologie Cochin- Pasteur 1417

    Paris, 75014

  • Hopital Nord-CHU Saint Etienne

    Saint-Priest-en-Jarez, 42270

  • CHRU de Tours- Hopital Bretonneau

    Tours, 37044

Other trials in France

Peru4 sites

  • Hospital Nacional Adolfo Guevara Velasco

    Cusco, 08002

  • Clinica Internacional S.A

    Lima, 41

  • Hospital Cayetano Heredia

    San Martín de Porres, Lima region, 31

  • Centro de Investigaciones Biomédicas - CIBIOM/Clinica Peruano Americana S.A

    Trujillo, La Libertad, 13011

Other trials in Peru

Belgium3 sites

  • Institut Jules Bordet

    Brussels, 1000

  • UZ Leuven

    Leuven, 3000

  • CHU de Liège - Domaine universitaire du Sart Tilman

    Liège, 4000

Other trials in Belgium

Taiwan3 sites

  • Kaohsiung Veterans General Hospital

    Kaohsiung City, Taiwan (r.o.c.), 81362

  • Far Eastern Memorial Hospital

    New Taipei City, 220

  • National Taiwan University Hospital

    Taipei, 10002

Other trials in Taiwan

About this study

Official title: A PHASE 3, PLACEBO-CONTROLLED, RANDOMIZED, OBSERVER-BLINDED STUDY TO EVALUATE THE EFFICACY, SAFETY, AND TOLERABILITY OF A CLOSTRIDIUM DIFFICILE VACCINE IN ADULTS 50 YEARS OF AGE AND OLDER

The Clover trial is evaluating an investigational vaccine that may help to prevent Clostridium difficile infection. Participants in the study are adults 50 years of age and older, who are at risk of developing Clostridium difficile infection. The study will assess whether the vaccine prevents the disease, and whether it is safe and well tolerated.

Each subject will receive 3 doses of Clostridium difficile vaccine or placebo and be followed for up to 3 years after vaccination for potential Clostridium difficile infection.

Being tested
Clostridium difficile vaccine, Placebo
Medical subject headings
Clostridium Infections

What participants receive

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

  • Clostridium difficile vaccineBiological

    Toxoid-based Clostridium difficile vaccine

  • PlaceboBiological

    Normal saline solution (0.9% sodium chloride)

Study groups in NCT03090191
Study groupRoleWhat they receive
Clostridium difficile vaccineExperimentalNot described
Receives: Biological: Clostridium difficile vaccine
PlaceboPlacebo comparatorNot described
Receives: Biological: Placebo

What is being measured

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

  1. Number of First Primary Episodes of Clostridium Difficile Infection (CDI) (Definition 1) Follow-up After Dose 3

    CDI definition 1 for a primary episode of CDI (no previous CDI onset in the prior 8 weeks) was defined as either a) presence of diarrhea, defined as passage of 3 or more unformed stools (Bristol stool chart types 5-7) in 24 or fewer consecutive hours, and stool sample that was positive for the toxin B gene (by polymerase chain reaction [PCR)] and positive for toxin A and/or toxin B, as measured in the central laboratory; or b) Pseudomembranous colitis diagnosed at colonoscopy, at surgery, or histopathologically; and corresponding stool sample that was positive for the toxin B gene (via PCR) as measured in the central laboratory. End of surveillance period was defined as accumulation of at least 40 CDI cases.

    Measured: From 14 days after Dose 3 to the end of the surveillance period (mean follow-up after dose 3 was 34.2 months)

  2. Number of First Primary Episodes of Clostridium Difficile Infection (CDI) (Definition 1) Follow-up After Dose 2

    CDI definition 1 for a primary episode of CDI (no previous CDI onset in the prior 8 weeks) was defined as either a) presence of diarrhea, defined as passage of 3 or more unformed stools (Bristol stool chart types 5-7) in 24 or fewer consecutive hours, and stool sample that was positive for the toxin B gene (by PCR) and positive for toxin A and/or toxin B, as measured in the central laboratory; or b) Pseudomembranous colitis diagnosed at colonoscopy, at surgery, or histopathologically; and corresponding stool sample that was positive for the toxin B gene (via PCR) as measured in the central laboratory. End of surveillance period was defined as accumulation of at least 40 CDI cases.

    Measured: From 14 days after Dose 2 to the end of the surveillance period (mean follow-up after dose 2 was 36 months)

  3. Percentage of Participants Reporting Local Reactions Within 7 Days After Dose 1

    Local reactions included redness, swelling and pain at injection site. These were recorded by participants in an electronic diary (e-diary). Redness and swelling were measured and recorded in measuring device units. One measuring device unit= 0.5 centimeter (cm) and graded as mild: 2.5 to 5.0 cm, moderate: greater than (>) 5.0 to 10.0 cm, severe: >10.0 cm. Grade 4 indicated necrosis or exfoliative dermatitis for redness and necrosis for swelling Pain at injection site was graded as mild: did not interfere with daily activity, moderate: interfered with daily activity, severe: prevented daily activity. Grade 4 indicated emergency room visit or hospitalization.

    Measured: Within 7 days after Dose 1 at Month 0

  4. Percentage of Participants Reporting Local Reactions Within 7 Days After Dose 2

    Local reactions included redness, swelling and pain at injection site. These were recorded by participants in an e-diary. Redness and swelling were measured and recorded in measuring device units. One measuring device unit= 0.5 cm and graded as mild: 2.5 to 5.0 cm, moderate: > 5.0 to 10.0 cm, severe: >10.0 cm. Grade 4 indicated necrosis or exfoliative dermatitis for redness and necrosis for swelling. Pain at injection site was graded as mild: did not interfere with daily activity, moderate: interfered with daily activity, severe: prevented daily activity. Grade 4 indicated emergency room visit or hospitalization.

    Measured: Within 7 days after Dose 2 at Month 1

  5. Percentage of Participants Reporting Local Reactions Within 7 Days After Dose 3

    Local reactions included redness, swelling and pain at injection site. These were recorded by participants in an e-diary. Redness and swelling were measured and recorded in measuring device units. One measuring device unit= 0.5 cm and graded as mild: 2.5 to 5.0 cm, moderate: > 5.0 to 10.0 cm, severe: >10.0 cm. Grade 4 indicated necrosis or exfoliative dermatitis for redness and necrosis for swelling. Pain at injection site was graded as mild: did not interfere with daily activity, moderate: interfered with daily activity, severe: prevented daily activity. Grade 4 indicated emergency room visit or hospitalization.

    Measured: Within 7 days after Dose 3 at Month 6

  6. Percentage of Participants Reporting Systemic Events Within 7 Days After Dose 1

    Systemic events included fever, fatigue, headache, joint pain, muscle pain and vomiting. These were recorded by participants in an e-diary. Fever was categorized as: mild: (38.0 to 38.4 degree Celsius [deg C]), moderate: (38.5 to 38.9 deg C), severe (39.0 to 40.0 deg C), potentially life threatening (> 40.0 deg C). Fatigue, headache, joint pain and muscle pain were graded as mild: did not interfere with activity, moderate: some interference with activity, severe: prevented daily activity, grade 4: emergency room visit or hospitalization. Vomiting was graded as mild: 1 to 2 times in 24 hours, moderate: >2 times in 24 hours, severe: required intravenous hydration, grade 4: emergency room visit or hospitalization for hypotensive shock.

    Measured: Within 7 days after Dose 1 at Month 0

  7. Percentage of Participants Reporting Systemic Events Within 7 Days After Dose 2

    Systemic events included fever, fatigue, headache, joint pain, muscle pain and vomiting. These were recorded by participants in an e-diary. Fever was categorized as: mild: (38.0 to 38.4 deg C), moderate: (38.5 to 38.9 deg C), severe (39.0 to 40.0 deg C), potentially life threatening (> 40.0 deg C). Fatigue, headache, joint pain and muscle pain were graded as mild: did not interfere with activity, moderate: some interference with activity, severe: prevented daily activity, grade 4: emergency room visit or hospitalization. Vomiting was graded as mild: 1 to 2 times in 24 hours, moderate: >2 times in 24 hours, severe: required intravenous hydration, grade 4: emergency room visit or hospitalization for hypotensive shock.

    Measured: Within 7 days after Dose 2 at Month 1

  8. Percentage of Participants Reporting Systemic Events Within 7 Days After Dose 3

    Systemic events included fever, fatigue, headache, joint pain, muscle pain and vomiting. These were recorded by participants in an e-diary. Fever was categorized as: mild: (38.0 to 38.4 deg C), moderate: (38.5 to 38.9 deg C), severe (39.0 to 40.0 deg C), potentially life threatening (> 40.0 deg C). Fatigue, headache, joint pain and muscle pain were graded as mild: did not interfere with activity, moderate: some interference with activity, severe: prevented daily activity, grade 4: emergency room visit or hospitalization. Vomiting was graded as mild: 1 to 2 times in 24 hours, moderate: >2 times in 24 hours, severe: required intravenous hydration, grade 4: emergency room visit or hospitalization for hypotensive shock.

    Measured: Within 7 days after Dose 3 at Month 6

  9. Number of Participants Reporting Adverse Events (AEs)

    An AE was defined as any untoward medical occurrence in a participant who received investigational product without regard to possibility of causal relationship. AEs included both serious and all non-serious adverse events. An SAE was defined as any untoward medical occurrence at any dose that resulted in any of the following outcomes: death; life-threatening (immediate risk of death); required inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity (substantial disruption of the ability to conduct normal life functions); congenital anomaly/birth defect; or that was considered as an important medical event. AEs included both SAEs and all Non-SAEs (except local and systemic events).

    Measured: From Day 1 of Dose 1 to 1 Month after Dose 3 (7 Months)

  10. Number of Participants Reporting Serious Adverse Events (SAEs)

    An SAE was defined as any untoward medical occurrence at any dose that resulted in any of the following outcomes: death; life-threatening (immediate risk of death); required inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity (substantial disruption of the ability to conduct normal life functions); congenital anomaly/birth defect; or that was considered as an important medical event.

    Measured: From Day 1 of Dose 1 up to 6 months after Dose 3 (up to Month 12)

Secondary outcomes (8)

  1. Number of All Episodes of CDI (Definition 1 and 2) After Dose 3

    CDI definition 1 for primary episode of CDI (no previous CDI onset in prior 8 weeks) and CDI definition 2 for recurrent episode (episode occurred 8 weeks or less after onset of previous episode [provided symptoms of previous episode resolved]) were both defined as either a) presence of diarrhea, (passage of 3 or more unformed stools [Bristol stool chart types 5-7]) in 24 or fewer consecutive hours, stool sample positive for toxin B gene (by PCR),positive for toxin A and/or toxin B, as measured in central laboratory; or b) Pseudomembranous colitis diagnosed at colonoscopy, surgery, histopathologically; and corresponding stool sample positive for toxin B gene (via PCR) as measured in central laboratory. End of surveillance period was defined as accumulation of at least 40 CDI cases.

    Measured: From 14 days after Dose 3 to the end of the surveillance period (mean follow-up after dose 3 was 34.2 months)

  2. Time to Resolution for Participants With First Primary Episodes of CDI (Definition 1) After Dose 3

    Resolution of the event was the last day on which the event was recorded in the e-diary or the date the event ends if it was unresolved during the participant diary-recording period (end date collected on the case report form [CRF]). CDI definition 1 for a primary episode of CDI (no previous CDI onset in the prior 8 weeks) was defined as either a) presence of diarrhea, defined as passage of 3 or more unformed stools (Bristol stool chart types 5-7) in 24 or fewer consecutive hours, and stool sample that was positive for the toxin B gene (by PCR) and positive for toxin A and/or toxin B, as measured in the central laboratory; or b) Pseudomembranous colitis diagnosed at colonoscopy, at surgery, or histopathologically; and corresponding stool sample that was positive for the toxin B gene (via PCR) as measured in the central laboratory. End of surveillance period was defined as accumulation of at least 40 CDI cases.

    Measured: From 14 days after Dose 3 to the end of the surveillance period (mean follow-up after dose 3 was 34.2 months)

  3. Proportion of Participants Who Required Medical Attention During First Primary Episode of CDI (Definition 1) After Dose 3

    CDI definition 1 for a primary episode of CDI (no previous CDI onset in the prior 8 weeks) was defined as either a) presence of diarrhea, defined as passage of 3 or more unformed stools (Bristol stool chart types 5-7) in 24 or fewer consecutive hours, and stool sample that was positive for the toxin B gene (by PCR) and positive for toxin A and/or toxin B, as measured in the central laboratory; or b) Pseudomembranous colitis diagnosed at colonoscopy, at surgery, or histopathologically; and corresponding stool sample that was positive for the toxin B gene (via PCR) as measured in the central laboratory. End of surveillance period was defined as accumulation of at least 40 CDI cases.

    Measured: From 14 days after Dose 3 to the end of the surveillance period (mean follow-up after dose 3 was 34.2 months)

  4. Number of Participants With Recurrent Episodes of CDI (Definition 2) After Dose 3

    CDI definition 2 for a recurrent episode (an episode of CDI that occurred 8 weeks or less after the onset of a previous CDI episode [provided the symptoms of the previous episode had resolved]), was defined as either a) presence of diarrhea, defined as passage of 3 or more unformed stools (Bristol stool chart types 5-7) in 24 or fewer consecutive hours; and stool sample that was positive for the toxin B gene (by PCR) and positive for toxin A and/or toxin B, as measured in the central laboratory; or b) Pseudomembranous colitis diagnosed at colonoscopy, at surgery, or histopathologically; and corresponding stool sample that was positive for the toxin B gene (by PCR) as measured in the central laboratory. End of surveillance period was defined as accumulation of at least 40 CDI cases.

    Measured: From 14 days after Dose 3 to the end of the surveillance period (mean follow-up after dose 3 was 34.2 months)

  5. Number of All Episodes of CDI (Definition 1 and 2) After Dose 2

    CDI definition 1 for primary episode of CDI (no previous CDI onset in prior 8 weeks) and CDI definition 2 for recurrent episode (episode occurred 8 weeks or less after onset of previous episode [provided symptoms of previous episode resolved]) were both defined as either a) presence of diarrhea, (passage of 3 or more unformed stools [Bristol stool chart types 5-7]) in 24 or fewer consecutive hours, stool sample positive for toxin B gene (by PCR),positive for toxin A and/or toxin B, as measured in central laboratory; or b) Pseudomembranous colitis diagnosed at colonoscopy, surgery, histopathologically; and corresponding stool sample positive for toxin B gene (via PCR) as measured in central laboratory. End of surveillance period was defined as accumulation of at least 40 CDI cases.

    Measured: From 14 days after Dose 2 to the end of the surveillance period (mean follow-up after dose 2 was 36 months)

  6. Number of Participants With Recurrent Episodes of CDI (Definition 2) After Dose 2

    CDI definition 2 for a recurrent episode (an episode of CDI that occurred 8 weeks or less after the onset of a previous CDI episode [provided the symptoms of the previous episode had resolved]), was defined as either a) presence of diarrhea, defined as passage of 3 or more unformed stools (Bristol stool chart types 5-7) in 24 or fewer consecutive hours; and stool sample that was positive for the toxin B gene (by PCR) and positive for toxin A and/or toxin B, as measured in the central laboratory; or b) Pseudomembranous colitis diagnosed at colonoscopy, at surgery, or histopathologically; and corresponding stool sample that was positive for the toxin B gene (by PCR) as measured in the central laboratory. End of surveillance period was defined as accumulation of at least 40 CDI cases.

    Measured: From 14 days after Dose 2 to the end of the surveillance period (mean follow-up after dose 2 was 36 months)

  7. Number of First Primary Episode of CDI (Definition 1) After Dose 2 and Before Dose 3

    CDI definition 1 for a primary episode of CDI (no previous CDI onset in the prior 8 weeks) was defined as either a) presence of diarrhea, defined as passage of 3 or more unformed stools (Bristol stool chart types 5-7) in 24 or fewer consecutive hours, and stool sample that was positive for the toxin B gene (by PCR) and positive for toxin A and/or toxin B, as measured in the central laboratory; or b) Pseudomembranous colitis diagnosed at colonoscopy, at surgery, or histopathologically; and corresponding stool sample that was positive for the toxin B gene (via PCR) as measured in the central laboratory. End of surveillance period was defined as accumulation of at least 40 CDI cases.

    Measured: From 14 days after Dose 2 to Dose 3 or the day the third vaccination was expected (168 days after Dose 2) for participants who received only 2 doses

  8. Number of Participants With Recurrent Episode of CDI (Definition 2) After Dose 2 and Before Dose 3

    CDI definition 2 for a recurrent episode (an episode of CDI that occurred 8 weeks or less after the onset of a previous CDI episode [provided the symptoms of the previous episode had resolved]), was defined as either a) presence of diarrhea, defined as passage of 3 or more unformed stools (Bristol stool chart types 5-7) in 24 or fewer consecutive hours; and stool sample that was positive for the toxin B gene (by PCR) and positive for toxin A and/or toxin B, as measured in the central laboratory; or b) Pseudomembranous colitis diagnosed at colonoscopy, at surgery, or histopathologically; and corresponding stool sample that was positive for the toxin B gene (by PCR) as measured in the central laboratory. End of surveillance period was defined as accumulation of at least 40 CDI cases.

    Measured: From 14 days after Dose 2 to Dose 3 or the day the third vaccination was expected (168 days after Dose 2) for participants who received only 2 doses

Timeline

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

  1. First posted24 Mar 2017
  2. Study start29 Mar 2017
  3. Primary completion21 Dec 2021
  4. Study completion21 Dec 2021

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
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
17,535 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03090191
Sponsor's protocol ID
B5091007
Other IDs
2016-003866-14, CLOVER, 2016
Acronym
Clover
Status last verified
Jan 2023
First submitted
20 Mar 2017
Last updated
13 Feb 2023
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.

Publications

  • Donskey CJ, Dubberke ER, Klein NP, Liles EG, Szymkowiak K, Wilcox MH, Lawrence J, Bouguermouh S, Zhang H, Koury K, Bailey R, Smith HM, Lockhart S, Lamberth E, Kalina WV, Pride MW, Webber C, Anderson AS, Jansen KU, Gruber WC, Kitchin N. CLOVER (CLOstridium difficile Vaccine Efficacy tRial) Study: A Phase 3, Randomized Trial Investigating the Efficacy and Safety of a Detoxified Toxin A/B Vaccine in Adults 50 Years and Older at Increased Risk of Clostridioides difficile Infection. Clin Infect Dis. 2024 Dec 17;79(6):1503-1511. doi: 10.1093/cid/ciae410.

    PubMed 39180325

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Clostridium difficile vaccine in people with Clostridium Difficile Infection, run by Pfizer at 426 sites in 23 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 5 inclusion and 19 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 13 Feb 2023. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 426 sites in United States, Japan, Bulgaria, Slovakia, South Korea and 18 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. Some participants in this study may receive a placebo. 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 13 Feb 2023). 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 First Primary Episodes of Clostridium Difficile Infection (CDI) (Definition 1) Follow-up After Dose 3 (time frame: From 14 days after Dose 3 to the end of the surveillance period (mean follow-up after dose 3 was 34.2 months)). The study lists 10 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 NCT03090191, which also lists 1 linked publication.

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 13 Feb 2023.

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