Cost‐Effectiveness of Once Weekly Rezafungin for the Treatment of Invasive Candidiasis in the United Kingdom

BACKGROUND: Invasive candidiasis (IC), 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 clinical trials, offering potential for earlier discharge. OBJECTIVE: To assess the cost-effectiveness of rezafungin versus daily echinocandins for the treatment of IC from a UK healthcare perspective. METHODS: An economic model was developed including a short-term decision tree (treatment duration ≤ 30 days) and a long-term Markov model (for lifetime outcomes). Considering the impact IC has on a patient's life expectancy and quality of life, a cost-utility analysis was performed. A cost-minimisation analysis assuming similar efficacy among echinocandins was included as scenario analysis. Treatment response was assessed at days 5/14 with nonresponders switching to second-line treatment. Patients with negative repeat blood cultures could step down to oral fluconazole. Rezafungin's weekly administration was estimated to lead to early discharge for 16% of patients. Risk of death was included. Efficacy and resource use estimates were from pooled trial data. Unit costs, utilities, long-term mortality were from published literature and UK databases. RESULTS: Rezafungin was estimated to be cost-saving compared to daily echinocandins (discounted incremental costs: -£6028 to -£6727 vs. daily echinocandins). Quality-adjusted life-years (QALYs) were similar (incremental QALY: 0.03 vs. daily echinocandins), resulting in rezafungin being cost-effective. Results were most sensitive to varying mortality and ICU length of stay. CONCLUSION: Once weekly rezafungin is a cost-saving and cost-effective treatment option in IC from the UK healthcare perspective.