Fidaxomicin (OPT-80) for the treatment of Clostridium difficile infection.

IMPORTANCE OF THE FIELD: Clostridium difficile infection (CDI) has become an increasingly important healthcare-associated complication in many countries. CDI outbreaks, a new 'hypervirulent' form and increased worldwide rates have underscored four urgent unmet needs for this disease: i) effective prevention of CDI; ii) therapies to produce faster resolution of CDI symptoms; iii) therapies to treat severe CDI more effectively and reduce its mortality; and iv) therapies to reduce the CDI recurrence rate following treatment. AREAS COVERED IN THIS REVIEW: Fidaxomicin, a new macrocyclic antibiotic, has demonstrated potent in vitro activity against C. difficile with limited or no activity against normal fecal flora. It is minimally absorbed from the intestinal tract, even in the presence of intestinal inflammation. When tested against oral vancomycin in clinical studies of CDI therapy, it has equivalent efficacy for curing CDI at end of treatment and a comparable safety profile to that agent. However, fidaxomicin therapy of CDI is associated with significantly fewer CDI recurrences in the 28 days following treatment. Symptom resolution is also slightly quicker in some CDI patients. Additional fecal flora analysis in the CDI trials showed that fewer individuals developed intestinal colonization with vancomycin-resistant enterococci (VRE) among the fidaxomicin-treated group. This new molecule, which has just completed two large Phase III multicenter studies, successfully addresses two of the four urgent and unmet needs for dealing with CDI. WHAT THE READER WILL GAIN: Fidaxomicin is as effective and as safe as vancomycin therapy for treating CDI but is associated with far fewer recurrences post-treatment and a decreased risk of VRE acquisition. TAKE HOME MESSAGE: Fidaxomicin is a potential new therapy for CDI which has the capacity to substantially decrease post-treatment recurrences and is as safe and well-tolerated as standard vancomycin treatment.