Mullane KM, et al. - In view of the common occurrence of Clostridium difficile–associated diarrhea (CDAD) during hematopoietic stem-cell transplantation (HSCT) and its link with increased morbidity and mortality, researchers assessed fidaxomicin for CDAD prevention in HSCT patients. In this double-blind study, patients undergoing HSCT with fluoroquinolone prophylaxis stratified by transplant type (autologous/allogeneic) were randomly allocated to once-daily oral fidaxomicin (200 mg) or a placebo. Although the arms were similar in terms of CDAD incidence through 30 days after study medication, the sensitivity analysis established that fidaxomicin significantly lowered CDAD incidence in HSCT recipients.