STOP-CDI: Efficacy of Fecal Microbiota Transplantation vs Fidaxomicin vs Vancomycin in Treating and Preventing Relapse of Clostridioides Difficile Infection

Summary

The STOP-CDI study is a multicenter, randomized, open-label, three-arm clinical trial comparing the efficacy of fecal microbiota transplantation (FMT) preceded by vancomycin, fidaxomicin monotherapy, and standard-of-care vancomycin in preventing recurrence of Clostridioides difficile infection (CDI) in high-risk adult patients.

CDI is a common healthcare-associated infection with rising incidence and high recurrence rates, particularly in elderly and immunocompromised individuals. While current guidelines recommend fidaxomicin as first-line therapy, its availability and reimbursement remain limited in some healthcare systems. FMT, although effective, is not widely implemented as first-line treatment. This study addresses the need for comparative, real-world data to inform treatment decisions for patients at high risk of severe or recurrent CDI.

Eligible participants include adults aged ≥65 years or younger patients with specific risk factors such as multiple comorbidities, prior CDI episodes, recent hospitalization, use of non-CDI antibiotics, or PPI therapy. Participants will be randomized in a 2:1:1 ratio to one of three treatment arms: (1) vancomycin plus FMT, (2) fidaxomicin, or (3) vancomycin alone. FMT is administered via capsules or, if necessary, alternative endoscopic routes.

The primary endpoint is CDI recurrence within 12 weeks following the initial treatment. Secondary endpoints include clinical cure, safety, and global cure. Exploratory analyses will assess microbiome changes and potential genomic predictors of response. A total of 424 participants will be enrolled across 10 clinical sites in Poland.

The study aims to provide robust, comparative evidence to support clinical guidelines and improve outcomes for patients with CDI, particularly in healthcare systems with limited access to novel therapies.

Conditions

• Clostridioides Difficile Infection
• Clostridioides Difficile Infection Recurrence
• Fecal Microbiota Transplantation (FMT)
• Comparative Effectiveness of CDI Treatments
• Fidaxomicin
• Vancomycin

Interventions

OTHER

FMT (fecal microbiota transplantation)

This intervention consists of a two-phase treatment for Clostridioides difficile infection in high-risk adults. First, participants receive a short-course (5 days) of oral vancomycin to reduce C. difficile bacterial load. Following antibiotic pretreatment, fecal microbiota transplantation (FMT) is administered to restore healthy gut microbiota. FMT is delivered primarily via encapsulated microbiota capsules, with alternative routes including colonoscopy, gastroscopy, nasojejunal tube, or rectal enema if capsules are contraindicated. A second FMT dose is given 7 days after the first, either as daily capsules over six days or as a single endoscopic administration. This approach aims to reduce CDI recurrence by combining targeted antibiotic reduction of pathogens with microbiome restoration.

DRUG

Fidaxomicin

Participants receive a 10-day course of fidaxomicin administered orally at a dose of 200 mg twice daily. Fidaxomicin is a narrow-spectrum macrocyclic antibiotic specifically targeting Clostridioides difficile with minimal impact on the normal gut microbiota. This monotherapy aims to eradicate C. difficile infection while preserving the intestinal microbiome, thereby reducing the risk of recurrence. No additional interventions are provided during the treatment period. Biological samples are collected before and after treatment to evaluate clinical response, safety, and microbiome changes.

DRUG

Vancomycin (VAN) treatment

Participants receive a 10-day course of oral vancomycin at a dose of 125 mg four times daily. Vancomycin is a broad-spectrum glycopeptide antibiotic commonly used as standard-of-care therapy for Clostridioides difficile infection. This monotherapy aims to eradicate C. difficile by reducing bacterial load in the colon. No additional interventions are applied during the treatment period. Biological samples are collected before and after treatment to monitor clinical outcomes, safety, and changes in the gut microbiome.

Sponsors & Collaborators

• Human Biome S.A.

  collaborator UNKNOWN

• Medical University of Warsaw

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-10-31

Primary Completion

2027-03-31

Completion

2027-04-30