Safety and Efficacy of Fidaxomicin Versus Placebo for Prophylaxis Against Clostridium Difficile-Associated Diarrhea in Adults Undergoing Hematopoietic Stem Cell Transplantation (MK-5119-001)
Safety and Efficacy of Fidaxomicin Versus Placebo for Prophylaxis Against Clostridium Difficile-Associated Diarrhea in Adults Undergoing Hematopoietic Stem Cell Transplantation (MK-5119-001)
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
 participants undergoing hematopoietic stem cell transplantation (HSCT). The primary
 hypothesis is that Fidaxomicin is superior to placebo in preventing CDAD in participants
 undergoing HSCT.
Inclusion Criteria:

 -  Male or female 18 years of age or older.

 -  Females 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). Males and females must agree to avoid
 conception during treatment and for four weeks following the end of study treatment.

 -  Is 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.

 -  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 participant in the study, would make it unlikely for the
 participant 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.