臨床研究等提出・公開システム

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 (BEETHOVEN)

A Study to Learn About a Clostridioides Difficile Vaccine in People 65 Years of Age and Older (BEETHOVEN)

Kawai Norisuke

Pfizer R&D Japan G.K.

Shinjuku Bunka Quint Bldg., 3-22-7 Yoyogi, Shibuya-ku, Tokyo

clinical-trials@pfizer.com

Clinical Trials Information Desk

Pfizer R&D Japan G.K.

Shinjuku Bunka Quint Bldg., 3-22-7 Yoyogi, Shibuya-ku, Tokyo

+81-3-5309-7000

clinical-trials@pfizer.com

Recruiting

May. 20, 2026

Interventional

randomized controlled trial

double blind

placebo control

parallel assignment

prevention purpose

Who Can Join the Study (Inclusion Criteria):

* People with recent or future planned contact with healthcare systems or who have recently received antibiotics.

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, kidney failure, or another serious health problem.

Both

* Clostridioides Difficile Associated Disease

* Biological: C.difficile vaccine
- C.difficile vaccine given as an intramuscular injection
* Other: Saline Placebo
- 0.9% sodium chloride solution given as a intramuscular injection

* 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

* 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)]
- First episode of primary CDI with antibiotic use incidence per 1000 person- years of follow- up
* The incidence of severe primary CDI as defined by Infectious Diseases Society of America (IDSA)/ Society for Healthcare Epidemiology of America (SHEA) [Time Frame: from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years)]
- First episode of severe or fulminant primary CDI incidence per 1000 person- years of follow- up
* 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)]
- First episode of primary CDI incidence per 1000 person- years of follow- up
* 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)]
- Time to all C.difficile infection cases

+81-3-6665-0572

April. 03, 2026

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.

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