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

Abstract

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 treatmentsequence modelwith nine health states and a 1year time horizon to assess costs and QALYs. Themodel was based on a healthcare systemperspective (NHS and Personal Social Services) in England. Sensitivity analyseswere 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 versus €260/patient), these were offset by lower total hospitalization costs (which also included treatment monitoring and community care costs; €10 815 versus €11459/patient) and lower costs ofmanaging adverse events (€694 versus €1199/patient), reflecting the lower incidence of CDI recurrence and adverse events with extended-pulsed fidaxomicin. Extended-pulsed fidaxomicin cost €53 less per patient than vancomycin over 1 year. The probability that first-line extended-pulsed fidaxomicinwas cost-effective at a willingness-to-pay threshold of €30000/QALYwas 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.