Extended-pulsed fidaxomicin versus vancomycin for Clostridium difficile infection in patients aged >= 60 years (EXTEND): analysis of cost-effectiveness

Objectives: The randomized Phase IIIb/IV EXTEND trial showed that extended-pulsed fidaxomicin significantly improved sustained clinical cure and reduced recurrence versus vancomycin in patients >= 60 years old with Clostridium difficile infection (CDI). Cost-effectiveness of extended-pulsed fidaxomicin versus vancomycin as first-line therapy for CDI was evaluated in this patient population. Methods: Clinical results from EXTEND and inputs from published sources were used in a semi-Markov treatment-sequence model with nine health states and a 1 year time horizon to assess costs and QALYs. The model was based on a healthcare system perspective (NHS and Personal Social Services) in England. Sensitivity analyses were performed. Results: Patients receiving first-line extended-pulsed fidaxomicin treatment had a 0.02 QALY gain compared with first-line vancomycin (0.6267 versus 0.6038 QALYs/patient). While total drug acquisition costs were higher for extended-pulsed fidaxomicin than for vancomycin when used first-line (1356 pound versus 260 pound/patient), these were offset by lower total hospitalization costs (which also included treatment monitoring and community care costs; 10 pound 815 versus 11459 pound/patient) and lower costs of managing adverse events (694 pound versus 1199 pound/patient), reflecting the lower incidence of CDI recurrence and adverse events with extended-pulsed fidaxomicin. Extended-pulsed fidaxomicin cost 53 pound less per patient than vancomycin over 1 year. The probability that first-line extended-pulsed fidaxomicin was cost-effective at a willingness-to-pay threshold of 30 pound 000/QALY was 76% in these patients. Conclusions: While fidaxomicin acquisition costs are higher than those of vancomycin, the observed reduced recurrence rate with extended-pulsed fidaxomicin makes it a more effective and less costly treatment strategy than vancomycin for first-line treatment of CDI in older patients.