OBJECTIVES: Candidemia and invasive candidiasis (C/IC), serious, life-threatening fungal infections with high economic burden, are often treated first-line with daily intravenous echinocandins. A new once weekly echinocandin, rezafungin demonstrated statistically non-inferior efficacy and numerically shorter intensive care unit (ICU) stay compared to caspofungin in phase 2 and 3 trials, with potential for earlier discharge. This study assessed the cost-effectiveness of rezafungin versus daily echinocandins for the treatment of C/IC from UK healthcare perspective.

METHODS: Hybrid model was developed including a short-term decision tree (capturing treatment duration ≤30 days) and a long-term Markov model (capturing lifetime outcomes). Trial data, network meta-analyses, and clinical experts suggested similar efficacy for all echinocandins, therefore cost-minimisation analysis was performed as base case and cost-utility analysis as scenario analysis. Treatment response was assessed at days 5 and 14. Non-responders were assumed to switch to second-line treatment. Patients with negative repeat blood cultures could step down to oral fluconazole. Weekly rezafungin administration could allow early discharge for 16% of all patients. Risk of death was included. Efficacy and resource use estimates were from pooled trial data, assuming equal efficacy/resource use for daily echinocandins. Unit costs, utilities, long-term mortality were from published literature and public UK databases. Annual discount rate was 3.5%. Conceptual/technical validation, probabilistic and deterministic sensitivity analyses were conducted.

RESULTS: Rezafungin was cost-saving compared to daily echinocandins (discounted incremental costs: -£7,789, -£8,344 and -£8,705 vs. caspofungin, micafungin and anidulafungin respectively). In scenario analysis, quality-adjusted life-years (QALYs) were similar (incremental QALY: -0.03 vs. all comparators), resulting in rezafungin being cost-effective (net monetary benefit with £20,000/QALY threshold: £7,154-£8,069 vs. daily echinocandins). Results were most sensitive to ICU length of stay and treatment response (day 14).

CONCLUSIONS: Once weekly rezafungin is a cost-saving and cost-effective treatment option in C/IC from the UK healthcare perspective compared to currently available options.