Experience With Fidaxomicin as First-Line Treatment for C. difficile Infection (CDI): Clinical Outcomes and Cost-Effectiveness

Abstract

Introduction: Our 1,200-bed hospital has used fidaxomicin, a novel macrocyclic antibiotic, as first-line treatment for microbiologically confirmed CDI in all adult patients since August 2012. In two phase 3 trials, fidaxomicin significantly lowered recurrence rate (13-15%), compared to vancomycin (25-27%). However, high acquisition costs have led to concerns about its use. We review clinical and cost-effectiveness analyses of first-line use of fidaxomicin. Methods: Clinical outcomes with fidaxomicin were assessed by follow-up of all adult patients treated for CDI (n=62). Recurrence rate was calculated and compared retrospectively with the recurrence rate in patients who tested positive for CDI and were treated with metronidazole or vancomycin during the previous financial year (n=86). Clinical, laboratory, and outcome data were compared. Financial data were collected for all CDI cases using the Synergy (CACI Ltd) patient-level information and costing system (PLICS) for the 2 periods (pre-fidaxomicin introduction, April 2011-March 2012; post-fidaxomicin introduction, August 2012-July 2013). Patients with hospital-acquired CDI were matched to controls without CDI within the same financial year and within 10 years of age by using the first 5 digits of the healthcare resource group code. Differences in expenditure between cases and controls were calculated to give the excess cost of a CDI case, which was used in conjunction with recurrence rates to evaluate the cost-effectiveness of fidaxomicin versus vancomycin or metronidazole. Fidaxomicin use as first-line therapy was considered to be cost-effective if the costs associated with a CDI case exceeded the acquisition costs for each case prevented. Results: Treated patients had a mean (range) age of 75 (19-100) years. The recurrence rate following treatment in fidaxomicin-treated patients was 6%, compared with 20% in historic controls treated with vancomycin or metronidazole during the previous year (p=0.03). Financial data for CDI were compared with 4,473 controls. Paired financial data were available for 34 patients treated with fidaxomicin and 77 historic controls treated with vancomycin or metronidazole. Spend on fidaxomicin to prevent one case of CDI was estimated to be £9,469. The estimated cost of a case of CDI was £17,451 more than matched controls without CDI. Excess cost of a first episode of CDI was £13,146 and was greater (£20,249) for first recurrences. Conclusion: These findings are consistent with the lower proportion of CDI recurrence in patients treated with fidaxomicin versus vancomycin in the registration trials. In our hospital, the acquisition cost of fidaxomicin was justified by the savings from reduced recurrence. Disclosure - Tim Planche - consultancy or paid speaker fees for Astellas, Pfizer, Summit, Cepheid, Launch Diagnostics, Becton Dickinson; received unrestricted educational grant from Astellas; Laura Whitney - speaker fees for Astellas, Gilead, Pfizer; Attiq Ahmed - financial disclosures - none; John Nesnas - speaker fees for Astellas. This research was supported by an industry grant from This work was supported by an unrestricted educational grant from Astellas.