Safety and Efficacy of Fidaxomicin Versus Placebo for Prophylaxis Against Clostridium Difficile-Associated Diarrhea in Adults Undergoing Hematopoietic Stem Cell Transplantation (DEFLECT-1)

This study has been completed.
Information provided by (Responsible Party):
Merck Sharp & Dohme Corp. Identifier:
First received: September 19, 2012
Last updated: April 27, 2015
Last verified: May 2014
The objective of this study is to demonstrate the efficacy and safety of fidaxomicin versus placebo for prophylaxis against Clostridium difficile-Associated Diarrhea (CDAD) in adult subjects undergoing hematopoietic stem cell transplantation (HSCT).

Condition Intervention Phase
Clostridium Difficile-Associated Diarrhea (CDAD)
Drug: fidaxomicin
Drug: placebo
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Prevention
Official Title: A Phase 3b Multi-Center, Double-Blind, Randomized, Placebo Controlled Study to Demonstrate the Safety and Efficacy of Fidaxomicin for Prophylaxis Against Clostridium Difficile-Associated Diarrhea in Adults Undergoing Hematopoietic Stem Cell Transplantation

Resource links provided by NLM:

Further study details as provided by Merck Sharp & Dohme Corp.:

Primary Outcome Measures:
  • The occurrence of CDAD from start of study treatment up to 30 days post-treatment follow-up in HSCT subjects. [ Time Frame: 30 days post-treatment ] [ Designated as safety issue: Yes ]

    CDAD is defined as:

    • Diarrhea: (change in bowel habits with >3 unformed bowel movements in a 24 hour period) and
    • Presence of either toxin A and/or B (or their respective genes, tcdA and/or tcdB) of C. difficile in the stool determined by C. difficile toxin assay

Secondary Outcome Measures:
  • Occurrence of CDAD from start of study treatment up to 60 days post-treatment [ Time Frame: Up to 60 days post-treatment ] [ Designated as safety issue: Yes ]
  • Occurrence of CDAD from start of study treatment up to Day 70 of study. [ Time Frame: Up to Day 70 of study ] [ Designated as safety issue: Yes ]

Enrollment: 611
Study Start Date: October 2012
Study Completion Date: April 2015
Primary Completion Date: April 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: fidaxomicin
200 mg fidaxomicin tablet once daily
Drug: fidaxomicin

Fidaxomicin 200 mg tablet once daily from the start of conditioning or at the time of fluoroquinolone initiation. Study drug treatment will continue until 7 days after either neutrophil engraftment or the completion of any fluoroquinolone antibiotic regimen (whichever occurs later).

Study drug treatment will stop at onset of CDAD or no longer than 40 days of duration, even if other antibiotics are still administered or neutrophil engraftment extends beyond 40 days.

Other Names:
  • OPT-80
  • PAR-101
Placebo Comparator: Placebo
Placebo tablet once daily
Drug: placebo


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Male or female 18 years of age or older.
  • Female subjects of childbearing potential must be using an adequate and reliable method of contraception (e.g., abstinence, barrier with additional spermicide foam or jelly, intrauterine device, hormonal contraception). Subjects (both male and female) must agree to avoid conception during treatment and for four weeks following the end of study treatment.
  • Individuals undergoing HSCT with planned fluoroquinolone prophylaxis.
  • Informed consent is provided.

Exclusion Criteria:

  • Ongoing active CDAD infection (as evidenced by clinical signs of diarrhea along with the presence of either toxin A and/or B [or their respective genes, tcdA and/or tcdB] of C. difficile in the stool) or current treatment for CDAD.
  • Undergoing cord blood transplants.
  • Subject has fulminant colitis, toxic megacolon, or ileus.
  • A history of inflammatory bowel disease (ulcerative colitis or Crohn's disease).
  • Women who are pregnant or are actively breast feeding (all women of childbearing potential must have a negative pregnancy test result prior to dosing study drug).
  • Use of any drugs potentially useful in the treatment of CDAD (e.g. oral vancomycin, metronidazole, oral bacitracin, fusidic acid, rifaximin, and nitazoxanide).
  • Any other condition that, in the opinion of the investigator, would jeopardize the safety or rights of the subject participating in the study, would make it unlikely for the subject to complete the study, or would confound the results of the study.
  • Participation in other clinical research studies utilizing an investigational agent within one month prior to screening and during the study treatment period.
  Contacts and Locations
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Please refer to this study by its identifier: NCT01691248

  Show 43 Study Locations
Sponsors and Collaborators
Merck Sharp & Dohme Corp.
Study Director: Pamela Sears, PhD Cubist Pharmaceuticals LLC
  More Information

No publications provided

Responsible Party: Merck Sharp & Dohme Corp. Identifier: NCT01691248     History of Changes
Other Study ID Numbers: 5119-001  OPT-80-302 
Study First Received: September 19, 2012
Last Updated: April 27, 2015
Health Authority: United States: Food and Drug Administration
Canada: Health Canada

Keywords provided by Merck Sharp & Dohme Corp.:
Clostridium difficile
Clostridium difficile-Associated Diarrhea
Hematopoietic Stem Cell Transplantation

Additional relevant MeSH terms:
Signs and Symptoms
Signs and Symptoms, Digestive processed this record on February 10, 2016