Clostridoides Difficile Associated DiseasePhase 3BEETHOVENNCT07282665
A Study to Learn About a Clostridioides Difficile Vaccine in People 65 Years of Age and Older
A Phase 3 study testing C.difficile vaccine in people with Clostridoides Difficile Associated Disease, run by Pfizer at 186 sites in 4 countries.
Trial summary
The purpose of the study is to learn about how effective, safe, and tolerable the Clostridioides difficile (C. difficile) vaccine is in decreasing the number of C. difficile infections (pCDI) in adults 65 years of age or older. The participants will receive either the C. difficile vaccine or placebo (saline). Read more about this study
- Who is it for?
- Ages 65 years and olderHealthy volunteers can take part
- Conditions the study is for
- Clostridoides Difficile Associated Disease
- What is being tested?
- C.difficile vaccine
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 32,500 participants
- Where
- 186 sitesin 4 countries
- Study dates
- 10 Dec 2025to 7 Jun 2029
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
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 65 years and older
- All sexes
- Healthy volunteers accepted
- Older adult
Who Can Join the Study (Inclusion Criteria):
- People with recent or future planned contact with healthcare systems, recent antibiotic exposure, or a diagnosis of certain chronic medical conditions.
Who Cannot Join the Study (Exclusion Criteria):
- Anyone who has had CDI before.
- Anyone who has had surgery to remove part of their small or large intestine.
- Anyone who often has diarrhea (meaning three or more loose stools in a day, more than once a month).
- Anyone who has already received a vaccine or special antibody treatment for C. difficile.
- Anyone who has had a serious allergic reaction to a vaccine or to any part of the study vaccines.
- Anyone who might not respond well to the vaccine because their immune system is weak (either from a disease or from treatment).
- Anyone with cancer that has spread or another serious health problem.
Trial locations and contacts
186 sites in 4 countries. Contact the study team or a site near you to ask about taking part.
186 sites in 4 countries
United States142 sites, 141 recruiting
- Recruiting
Albuquerque Clinical Trials, Inc.
Albuquerque, New Mexico, 87102
- Recruiting
Accellacare - McFarland
Ames, Iowa, 50010
- Recruiting
McFarland Clinic, PC
Ames, Iowa, 50010
- Recruiting
North Alabama Research Center
Athens, Alabama, 35611
- Recruiting
Emory Steiner Building Research Center
Atlanta, Georgia, 30303
- Recruiting
Emory University Woodruff Extension Building (WEB)
Atlanta, Georgia, 30303
- Recruiting
Johns Hopkins Bloomberg School of Public Health
Baltimore, Maryland, 21205
- Recruiting
Johns Hopkins Bloomberg School of Public Health
Baltimore, Maryland, 21231
- Recruiting
Ochsner Medical Complex - The Grove
Baton Rouge, Louisiana, 70836
- Recruiting
Bay Pines VA Healthcare System
Bay Pines, Florida, 33744
- Recruiting
NYU Langone Health
Brooklyn, New York, 11220
- Recruiting
The University of Vermont Medical Center Inc.
Burlington, Vermont, 05401
- Recruiting
UVM Larner College of Medicine MMG/VCT
Burlington, Vermont, 05401
- Recruiting
Capital Area Research, LLC
Camp Hill, Pennsylvania, 17011
- Recruiting
Accellacare - Cary
Cary, North Carolina, 27518
- Recruiting
Chinle Center for Indigenous Health
Chinle, Arizona, 86503
- Recruiting
Chinle Comprehensive Health Care Facility
Chinle, Arizona, 86503
- Recruiting
CTI Clinical Research Center
Cincinnati, Ohio, 45212
- Recruiting
VA Northeast Ohio Healthcare System Louis Stokes Cleveland VA Medical Center
Cleveland, Ohio, 44106
- Recruiting
Centricity Research Columbus Georgia Multispecialty
Columbus, Georgia, 31904
- Recruiting
Family Health Watch - KeyPoint Clinical Research
Dallas, Texas, 75237
- Recruiting
KeyPoint Clinical Research
Dallas, Texas, 75240
- Recruiting
North Texas Infectious Diseases Consultants, P.A
Dallas, Texas, 75246
- Recruiting
Kaiser Permanente Daly City
Daly City, California, 94015
- Recruiting
The Hope Clinic of Emory University
Decatur, Georgia, 30030
- Recruiting
Atlanta VA Medical Center
Decatur, Georgia, 30033
- Recruiting
Duke Vaccine and Trials Unit
Durham, North Carolina, 27703
- Recruiting
Upstate Global Health Institute
East Syracuse, New York, 13057
- Recruiting
Cedar Health Research - Euless
Euless, Texas, 76040
- Recruiting
Providence Regional Medical Center Everett
Everett, Washington, 98201
- Recruiting
Proactive Clinical Research,LLC
Fort Lauderdale, Florida, 33308
- Recruiting
Gallup Center for Indigenous Health
Gallup, New Mexico, 87301
- Recruiting
Gallup Indian Medical Center
Gallup, New Mexico, 87301
- Recruiting
Velocity Clinical Research, Grand Island
Grand Island, Nebraska, 68803
- Recruiting
Medication Management
Greensboro, North Carolina, 27401
- Recruiting
Lakeview Clinical Research
Guntersville, Alabama, 35976
- Recruiting
Hackensack Meridian Health Hackensack University Medical Center
Hackensack, New Jersey, 07601
- Recruiting
HMH David Jurist Research Building
Hackensack, New Jersey, 07601
- Recruiting
HMH Hackensack University Medical Center
Hackensack, New Jersey, 07601
- Recruiting
Accellacare - Hickory
Hickory, North Carolina, 28601
- Recruiting
Atrium Health Wake Forest Baptist Infectious Disease-High Point
High Point, North Carolina, 27262
- Recruiting
Baylor College of Medicine
Houston, Texas, 77030
- Recruiting
Memorial Hermann Hospital - TMC
Houston, Texas, 77030
- Recruiting
The University of Texas Health Science Center at Houston
Houston, Texas, 77030
- Recruiting
UT Physicians
Houston, Texas, 77030
- Recruiting
DM Clinical Research- Cyfair
Houston, Texas, 77065
- Recruiting
Mercury Clinical Research - Santa Clara Family Clinic
Houston, Texas, 77087
- Recruiting
Medical Affiliated Research Center
Huntsville, Alabama, 35801
- Recruiting
Clinical Neuroscience Solutions, LLC
Jacksonville, Florida, 32256
- Recruiting
Ochsner Clinic Foundation - Kenner Clinical Trials Unit
Kenner, Louisiana, 70065
- Recruiting
New Phase Research and Development
Knoxville, Tennessee, 37909
- Recruiting
Ochsner Lafayette General Medical Center
Lafayette, Louisiana, 70503
- Recruiting
M3 Wake Research - Lake City
Lake City, Florida, 32055
- Recruiting
Walker Family Care
Little River, South Carolina, 29566
- Recruiting
Applied Research Center of Arkansas
Little Rock, Arkansas, 72205
- Recruiting
Mount Sinai Queens
Long Island City, New York, 11102
- Recruiting
Kaiser Permanente Los Angeles Medical Center
Los Angeles, California, 90027
- Recruiting
Kaiser Permanente Oncology Pharmacy #014C
Los Angeles, California, 90027
- Recruiting
North Shore University Hospital
Manhasset, New York, 11030
- Recruiting
Northwell Health Infectious Disease
Manhasset, New York, 11030
- Recruiting
Sacramento VA Medical Center
Mather, California, 95655
- Recruiting
South Florida Research Organization
Medley, Florida, 33166
- Recruiting
DM Clinical Research - Chicago
Melrose Park, Illinois, 60160
- Recruiting
Clinical Neuroscience Solutions, LLC
Memphis, Tennessee, 38119
- Recruiting
Care Research Inc
Miami, Florida, 33130
- Recruiting
Entrust Clinical Research
Miami, Florida, 33176
- Recruiting
Charisma Medical and Research Center
Miami Lakes, Florida, 33014
- Recruiting
Palm Springs Community Health Center
Miami Lakes, Florida, 33014
- Recruiting
Indago Research & Health Center, Inc
Miami Lakes, Florida, 33016
- Recruiting
NYU Langone Health
Mineola, New York, 11501
- Recruiting
Northern Westchester Hospital
Mount Kisco, New York, 10549
- Recruiting
The Vanderbilt Vaccine Research Program Clinic at The Village at Vanderbilt
Nashville, Tennessee, 37212
- Recruiting
Vanderbilt Investigational Drug Service (IDS)
Nashville, Tennessee, 37232
- Recruiting
Vanderbilt University Medical Center
Nashville, Tennessee, 37232
- Recruiting
Vanderbilt Vaccine Research Program Laboratory
Nashville, Tennessee, 37232
- Recruiting
Vanderbilt Vaccine Research Program
Nashville, Tennessee, 37232
- Recruiting
Hackensack Meridian Health Jersey Shore University Medical Center
Neptune City, New Jersey, 07753
- Recruiting
HOPE Tower at Jersey Shore University Medical Center
Neptune City, New Jersey, 07753
- Recruiting
Rutgers Robert Wood Johnson Medical School
New Brunswick, New Jersey, 08901
- Recruiting
NYU Langone Health
New York, New York, 10016
- Recruiting
Mount Sinai West
New York, New York, 10019
- Recruiting
Mount Sinai Morningside
New York, New York, 10025
- Recruiting
Icahn School of Medicine at Mount Sinai
New York, New York, 10029
- Recruiting
Columbia University Irving Medical Center
New York, New York, 10032
- Recruiting
AMR Clinical
Newton, Kansas, 67114
- Recruiting
Kaiser Permanente Oakland
Oakland, California, 94611
- Recruiting
University of Nebraska Medical Center
Omaha, Nebraska, 68105
- Recruiting
Velocity Clinical Research, Omaha
Omaha, Nebraska, 68134
- Recruiting
University Of Nebraska Medical Center
Omaha, Nebraska, 68198
- Recruiting
Kaiser Permanente Ontario Medical Center
Ontario, California, 91761
- Recruiting
DM Clinical Research - Philadelphia
Philadelphia, Pennsylvania, 19107
- Recruiting
Kaiser Permanente Center for Health Research
Portland, Oregon, 97227
- Recruiting
Accellacare - Raleigh
Raleigh, North Carolina, 27609
- Recruiting
Duke University Health System-Duke Vaccine and Trials Unit Raleigh
Raleigh, North Carolina, 27609
- Recruiting
Duke University Health System
Raleigh, North Carolina, 27609
- Recruiting
Raleigh Medical Group P.A.
Raleigh, North Carolina, 27609
- Recruiting
Renown Center for Advanced Medicine
Reno, Nevada, 89502
- Recruiting
Renown Regional Medical Center
Reno, Nevada, 89502
- Recruiting
University Health
Reno, Nevada, 89519
- Recruiting
Clinical Research Partners, LLC
Richmond, Virginia, 23226
- Recruiting
Rochester Clinical Research, LLC
Rochester, New York, 14609
- Recruiting
Kaiser Permanente Roseville
Roseville, California, 95661
- Recruiting
Kaiser Permanente Sacramento
Sacramento, California, 95815
- Recruiting
Kaiser Permanente South Sacramento
Sacramento, California, 95823
- Recruiting
Accellacare - Salisbury
Salisbury, North Carolina, 28144
- Recruiting
J. Lewis Research, Inc. / Foothill Family Clinic South
Salt Lake City, Utah, 84121
- Recruiting
Velocity Clinical Research, San Bernardino
San Bernardino, California, 92408
- Recruiting
Kaiser Permanente - San Diego Medical Center
San Diego, California, 92123
- Recruiting
Kaiser Permanente Viewridge Medical Office
San Diego, California, 92123
- Recruiting
Kaiser Permanente San Jose
San Jose, California, 95119
- Active, not recruiting
Carbon Health - San Mateo - Hillsdale Mall
San Mateo, California, 94403
- Recruiting
Kaiser Permanente Santa Clara
Santa Clara, California, 95051
- Recruiting
Velocity Clinical Research, Savannah
Savannah, Georgia, 31406
- Recruiting
Kaiser Permanente Washington Health Research Institute (KPWHRI)
Seattle, Washington, 98101
- Recruiting
University of Washington - Harborview Medical Center
Seattle, Washington, 98104
- Recruiting
Northern Navajo Medical Center
Shiprock, New Mexico, 87420
- Recruiting
Shiprock Center for Indigenous Health
Shiprock, New Mexico, 87420
- Recruiting
Velocity Clinical Research, Sioux City
Sioux City, Iowa, 51106
- Recruiting
Phelps Hospital Geriatric Medicine & Improvement Science
Sleepy Hollow, New York, 10591
- Recruiting
South Jersey Infectious Disease
Somers Point, New Jersey, 08244
- Recruiting
Revive Research Institute, Inc.
Southfield, Michigan, 48075
- Recruiting
DM Clinical Research - Detroit
Southfield, Michigan, 48076
- Recruiting
Velocity Clinical Research, Spartanburg
Spartanburg, South Carolina, 29303
- Recruiting
Washington University School of Medicine
St Louis, Missouri, 63110
- Recruiting
Sundance Clinical Research
St Louis, Missouri, 63141
- Recruiting
Staten Island University Hospital
Staten Island, New York, 10305
- Recruiting
Epic Medical Research-Sun City
Sun City, Arizona, 85351
- Recruiting
Angels Clinical Research Institute
Tampa, Florida, 33614
- Recruiting
Montefiore Medical Center
The Bronx, New York, 10467
- Recruiting
James J. Peters VA Medical Center
The Bronx, New York, 10468
- Recruiting
Med Partners, Inc. dba Premiere Medical Center of Burbank, Inc.
Toluca Lake, California, 91602
- Recruiting
Dynamed Clinical Research, LP d/b/a DM Clinical Research
Tomball, Texas, 77375
- Recruiting
Northwest Houston Heart Center
Tomball, Texas, 77375
- Recruiting
Kaiser Permanente Walnut Creek
Walnut Creek, California, 94596
- Recruiting
Diablo Clinical Research, Inc.
Walnut Creek, California, 94598
- Recruiting
GW Vaccine Research Unit
Washington D.C., District of Columbia, 20037
- Recruiting
The GW Medical Faculty Associates
Washington D.C., District of Columbia, 20037
- Recruiting
VA Boston Healthcare System - West Roxbury
West Roxbury, Massachusetts, 02132
- Recruiting
Accellacare - Wilmington
Wilmington, North Carolina, 28401
- Recruiting
Wilmington Health, PLLC
Wilmington, North Carolina, 28401
- Recruiting
Accellacare - Winston-Salem
Winston-Salem, North Carolina, 27103
- Recruiting
Wake Forest Baptist Health
Winston-Salem, North Carolina, 27157
United Kingdom19 sites, 19 recruiting
- Recruiting
Ormeau Clinical Trials
Belfast, Northern Ireland, BT2 8BG
- Recruiting
Synexus Midlands Clinical Research Centre
Birmingham, B16 8QQ
- Recruiting
Layton Medical Centre
Blackpool, Lancashire, FY3 7EN
- Recruiting
Cheadle Community Hospital
Cheadle, Staffordshire, ST10 1NS
- Recruiting
Lakeside Surgery
Corby, Northamptonshire, NN17 2UR
- Recruiting
Royal Devon & Exeter Hospital
Exeter, Devon, EX2 5DW
- Not yet recruiting
Synexus Scotland Clinical Research Centre
Glasgow, Glasgow CITY, ML4 3NJ
- Recruiting
Panthera Biopartners - Glasgow
Glasgow, G51 4RY
- Recruiting
Manchester Royal Infirmary
Manchester, M13 9WU
- Recruiting
Synexus Manchester Clinical Research Centre
Manchester, M15 6SE
- Recruiting
Newquay Health Centre
Newquay, Cornwall, TR7 1RU
- Recruiting
Knowle House Surgery
Plymouth, Devon, PL5 3JB
- Recruiting
Panthera Biopartners - Preston
Preston, England, PR2 9QB
- Recruiting
Panthera Biopartners - Manchester
Rochdale, Manchester, OL11 4AU
- Recruiting
Panthera Biopartners - Sheffield
Sheffield, S2 5FX
- Recruiting
Southampton General Hospital
Southampton, Hampshire, SO16 6YD
- Recruiting
Brunel Medical Practice (St Marychurch)
Torquay, Devon, TQ1 4QX
- Not yet recruiting
North Wales Clinical Research Facility
Wrexham, Wrexham [wrecsam Gb-wrc], LL13 7YP
- Recruiting
Panthera Clinic - York
York, North Yorkshire, YO24 4LJ
Japan14 sites, 14 recruiting
- Recruiting
Tokyo-Eki Center-building Clinic
Chuo-ku, Tokyo, 103-0027
- Recruiting
Nozaki Tokushukai Hospital
Daitō, Osaka, 574-0074
- Recruiting
Aso Iizuka Hospital
Iizuka-shi, Fukuoka, 820-8505
- Recruiting
Seishinkai Inoue Hospital
Itoshima, Fukuoka, 819-1104
- Recruiting
Japan Community Healthcare Organization Kyushu Hospital
Kitakyushu-shi, Fukuoka, 806-8501
- Recruiting
Koga General Hospital
Koga, Ibaraki, 306-0041
- Recruiting
Japanese Red Cross Kumamoto Hospital
Kumamoto, Kumamoto, 861-8520, 862-8520
- Recruiting
Kojunkai Daido Clinic
Nagoya, Aichi-ken, 457-8511
- Recruiting
Kamiiida daiichi General Hospital
Nagoya, Aichi-ken, 462-0802
- Recruiting
National Hospital Organization Nagasaki Medical Center
Ōmura, Nagasaki, 856-8562
- Recruiting
Fukuoka Shinmizumaki Hospital
Onga-gun, Fukuoka, 807-0051
- Recruiting
Saga University Hospital
Saga, Saga-ken, 849-8501
- Recruiting
Nanbu Tokushukai Hospital
Shimajiri, Okinawa, 901-0417
- Recruiting
National Center for Global Health and Medicine
Shinjuku, Tokyo, 162-8655
Argentina11 sites, 11 recruiting
- Recruiting
Fundación Huésped
Buenos Aires, Buenos Aires F.D., 1427
- Recruiting
Equipo Ciencia
Buenos Aires, Buenos Aires F.D., C1428BNF
- Recruiting
Sanatorio Sagrado Corazón
Buenos Aires, 1039
- Recruiting
Centro Medico Barrio Parque
Buenos Aires, 1425
- Recruiting
Clinica Privada del Sol S.A
Córdoba, Córdoba Province, X5000IIH
- Recruiting
Instituto Médico Platense (IMP)
La Plata, Buenos Aires, 1900
- Recruiting
CDC Centro Médico
Lujan de Cuyo, Mendoza Province, 5505
- Recruiting
Clinica Del Niño Y La Madre
Mar del Plata, Buenos Aires, 7600
- Recruiting
Investigaciones Clínicas Salta (ICSAL)
Salta, A4400
- Recruiting
Clinica Mayo de Urgencias Médicas Cruz Blanca S.R.L
San Miguel de Tucumán, Tucumán Province, 4000
- Recruiting
Hospital de Clinicas Presidente Nicolas Avellaneda
San Miguel de Tucumán, Tucumán Province, 4000
About this study
Official title: A PHASE 3, PLACEBO-CONTROLLED, DOUBLE-BLINDED, RANDOMIZED STUDY TO EVALUATE THE EFFICACY, SAFETY, AND TOLERABILITY OF A CLOSTRIDIOIDES DIFFICILE VACCINE IN ADULTS 65 YEARS OF AGE AND OLDER
The purpose of the study is to learn about how effective, safe, and tolerable the Clostridioides difficile (C. difficile) vaccine is in decreasing the number of C. difficile infections (pCDI) in adults 65 years of age or older.
The participants will receive either the C. difficile vaccine or placebo (saline). A placebo does not contain any active ingredients. The vaccines will be given as a shot into the upper arm muscle.
Read more
This study looks at the number of diarrhea (loose stools) events related to a C. difficile infection, so the length of the study can change. If these events happen quickly, the study may finish sooner; if they happen slowly, it could take longer. Sometimes, the study might stop early if the vaccine clearly does not work. Participants will stay in the study until enough events have occurred to answer the main question. On average, each person is expected to take part for up to about three and a half years.
During this time, participants will have 3 planned clinic visits and 3 planned phone visits. After these visits, more scheduled clinic visits will happen every year until the end of study.
Besides the scheduled study visits, if at any time during the study a participant has 3 or more loose stools in 24 hours, they will be asked to save the next one (the fourth or later) and contact the study site. The study site will check to see if it could be a C. difficile infection. This check may happen at the clinic or through a phone or video call.
- Being tested
- C.difficile vaccine, Saline Placebo
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
C.difficile vaccineBiological
C.difficile vaccine given as an intramuscular injection
Saline PlaceboOther
0.9% sodium chloride solution given as a intramuscular injection
| Study group | Role | What they receive |
|---|---|---|
| C.difficile vaccine | Experimental | Novel vaccine formulation Receives: Biological: C.difficile vaccine |
| Saline Placebo | Other | Not described Receives: Other: Saline Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
The percentage of participants reporting local reactions
Injection site pain, redness, and swelling as self-reported in electronic diaries
Measured: For 7 days after each vaccination
The percentage of participants reporting systemic events
Fever, vomiting, fatigue, headache, muscle pain, and joint pain as self-reported in electronic diaries
Measured: For 7 days after each vaccination
Percentage of participants reporting adverse events
As elicited by investigator site staff
Measured: From each vaccination through 1 month after each vaccination
Percentage of participants reporting serious adverse events
As elicited by investigator site staff
Measured: From Vaccination 1 (Day 1) through 12 months after Vaccination 2 (last dose) (18 months)
The incidence of the first episode of medically attended and clinically meaningful primary Clostridioides difficile infection (CDI)
First episode of medically attended and clinically meaningful primary CDI incidence per 1000 person- years of follow- up
Measured: from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
The incidence of the first episode of medically attended primary CDI
First episode of medically attended primary CDI incidence per 1000 person- years of follow- up
Measured: from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
The incidence of the first episode of clinically meaningful primary CDI
First episode of clinically meaningful primary CDI incidence per 1000 person- years of follow- up
Measured: from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
Secondary outcomes (4)
The incidence of antibiotic use in the treatment of a first episode of the primary CDI
First episode of primary CDI with antibiotic use incidence per 1000 person- years of follow- up
Measured: from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
The incidence of severe or fulminant primary CDI
First episode of severe or fulminant primary CDI incidence per 1000 person- years of follow- up
Measured: from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
The incidence of a first episode of primary CDI (any severity)
First episode of primary CDI incidence per 1000 person- years of follow- up
Measured: from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
The incidence of all CDI (primary and recurrent)
Occurence of all C.difficile infection cases
Measured: from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Dec 2025
- Study start10 Dec 2025
- Primary completion11 Dec 2028 (estimated)
- Study completion7 Jun 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Clostridoides Difficile Associated DiseaseStudies of the same condition, open and under way.
- More trials run by PfizerThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- 32,500 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07282665
- Sponsor's protocol ID
- C4771002
- Acronym
- BEETHOVEN
- Status last verified
- Oct 2026
- First submitted
- 5 Dec 2025
- Last updated
- 13 Oct 2026
- Results posted
- No
- 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.
Study at a glance
From the registry record, last updated by the sponsor on 13 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A PHASE 3, PLACEBO-CONTROLLED, DOUBLE-BLINDED, RANDOMIZED STUDY TO EVALUATE THE EFFICACY, SAFETY, AND TOLERABILITY OF A CLOSTRIDIOIDES DIFFICILE VACCINE IN ADULTS 65 YEARS OF AGE AND OLDER
- ClinicalTrials.gov ID
- NCT07282665
- Acronym / sponsor ID
- BEETHOVEN / C4771002
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 32,500 participants (estimated)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 10 Dec 2025 (actual)
- Primary completion
- 11 Dec 2028 (estimated)
- Study completion
- 7 Jun 2029 (estimated)
- First posted
- 15 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of the study is to learn about how effective, safe, and tolerable the Clostridioides difficile (C. difficile) vaccine is in decreasing the number of C. difficile infections (pCDI) in adults 65 years of age or older.
The participants will receive either the C. difficile vaccine or placebo (saline). A placebo does not contain any active ingredients. The vaccines will be given as a shot into the upper arm muscle.
This study looks at the number of diarrhea (loose stools) events related to a C. difficile infection, so the length of the study can change. If these events happen quickly, the study may finish sooner; if they happen slowly, it could take longer. Sometimes, the study might stop early if the vaccine clearly does not work. Participants will stay in the study until enough events have occurred to answer the main question. On average, each person is expected to take part for up to about three and a half years.
During this time, participants will have 3 planned clinic visits and 3 planned phone visits. After these visits, more scheduled clinic visits will happen every year until the end of study.
Besides the scheduled study visits, if at any time during the study a participant has 3 or more loose stools in 24 hours, they will be asked to save the next one (the fourth or later) and contact the study site. The study site will check to see if it could be a C. difficile infection. This check may happen at the clinic or through a phone or video call.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| C.difficile vaccine | Experimental | Biological: C.difficile vaccineNovel vaccine formulation |
| Saline Placebo | Other | Other: Saline Placebo |
Who may qualify
- Ages
- 65 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Older adult
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| C.difficile vaccineC.difficile vaccine given as an intramuscular injection | Biological | C.difficile vaccine |
| Saline Placebo0.9% sodium chloride solution given as a intramuscular injection | Other | Saline Placebo |
Primary outcome
The percentage of participants reporting local reactions
Time frame: For 7 days after each vaccination
Injection site pain, redness, and swelling as self-reported in electronic diaries
The percentage of participants reporting systemic events
Time frame: For 7 days after each vaccination
Fever, vomiting, fatigue, headache, muscle pain, and joint pain as self-reported in electronic diaries
Percentage of participants reporting adverse events
Time frame: From each vaccination through 1 month after each vaccination
As elicited by investigator site staff
Percentage of participants reporting serious adverse events
Time frame: From Vaccination 1 (Day 1) through 12 months after Vaccination 2 (last dose) (18 months)
As elicited by investigator site staff
The incidence of the first episode of medically attended and clinically meaningful primary Clostridioides difficile infection (CDI)
Time frame: from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
First episode of medically attended and clinically meaningful primary CDI incidence per 1000 person- years of follow- up
The incidence of the first episode of medically attended primary CDI
Time frame: from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
First episode of medically attended primary CDI incidence per 1000 person- years of follow- up
The incidence of the first episode of clinically meaningful primary CDI
Time frame: from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
First episode of clinically meaningful primary CDI incidence per 1000 person- years of follow- up
4 secondary outcomes
The incidence of antibiotic use in the treatment of a first episode of the primary CDI
Time frame: from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
The incidence of severe or fulminant primary CDI
Time frame: from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
The incidence of a first episode of primary CDI (any severity)
Time frame: from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
The incidence of all CDI (primary and recurrent)
Time frame: from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Oct 2026.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: 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.
Related trials for Clostridoides Difficile Associated Disease
RecruitingPhase 2/3
Secondary Prevention of Clostridioides Difficile Using Vancomycin
Clostridioides Difficile Infection, Clostridioides Difficile Infection Recurrence
Active, not recruitingPhase 1/2
To Understand the Safety and Effects of a C. Difficile Vaccine With New Adds-Ons That Will Be Given to Healthy Adults
Clostridoides Difficile Associated Disease
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Pfizer CT.gov Call Center study director
Pfizer
186 sites in 4 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing C.difficile vaccine in people with Clostridoides Difficile Associated Disease, run by Pfizer at 186 sites in 4 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
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: looking for participants now, as of the sponsor's last update on 13 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 186 sites in United States, United Kingdom, Japan, Argentina. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Pfizer CT.gov Call Center (1-800-718-1021, ClinicalTrials.gov_Inquiries@pfizer.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The percentage of participants reporting local reactions (time frame: For 7 days after each vaccination). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 Oct 2026.