Pharmacoeconomic evaluation of isavuconazole, posaconazole and voriconazole in the treatment of invasive fungal infection: initial therapy prior to pathogen differential diagnosis in China

Abstract Background Invasive fungal infections (IFIs) is associated with high mortality and a substantial economic burden. For high-risk patients, fever drive or diagnostic drive therapy is usually initiated prior to the differential diagnosis of the pathogen. This study evaluated the cost-effectiveness of isavuconazole, posaconazole, versus voriconazole in the treatment of invasive fungal infections from the perspective of the Chinese healthcare system, informing healthcare decision-making and resource allocation. Methods A decision analytic model was constructed using TreeAge Pro 2011 software to evaluate the cost-effectiveness of the entire disease course. We assumed that the prevalence of mucormycosis in the patients entering the model was 7.8%. Efficacy, cost, adverse events, and other data included in the model were mainly derived from clinical studies, published literature, and publicly available databases. The primary outcomes of the model output were total cost, quality-adjusted life years (QALYs), life years (Lys), and incremental cost-effectiveness ratio (ICER). The willing-to-pay (WTP) threshold was defined as one to three times China’s GDP per capita in 2022. One-way sensitivity analysis and probability sensitivity analysis were used to determine the robustness of the model. At the same time, the cost-effectiveness of three triazole antifungal agents under a broader range of mucormycosis prevalence, when voriconazole was covered by medical insurance reimbursement, and after the price reduction of posaconazole was discussed. Results Base-case analysis showed that isavuconazole had greater efficacy (+ 0.38 LYs and + 0.31 QALYs) than voriconazole; ICER was $15,702.46 /QALY, well below the WTP threshold ($38,223 /QALY). However, posaconazole did not provide a significant economic advantage over voriconazole (ICER $64,466.57 /QALY). One-way sensitivity analysis found that ICER was highly sensitive to the mortality of patients with invasive aspergillus infection. In the probabilistic sensitivity analysis, when the WTP threshold was $38223 /QALY, the probability of isavuconazole being cost-effective was 72.9%. The scenario analysis results indicated that posaconazole would become cost-effective when the price was reduced by 15% or the prevalence of mucormycosis was 14%. Conclusions Isavuconazole represents a cost-effective initial option for treating IFIs in high-risk patients prior to the differential diagnosis of pathogens. It will also be economical when a 15% reduction in posaconazole cost is achieved.