OBJECTIVES: Darolutamide was recently approved in the United States (US) for the treatment of metastatic hormone-sensitive prostate cancer (mHSPC) based on results from the ARASENS trial. This study aims to evaluate the cost-effectiveness of adding darolutamide to androgen deprivation therapy (ADT) plus docetaxel for the treatment of mHSPC in older adults from a US healthcare sector perspective.

METHODS: We developed a partitioned-survival model with three health states (progression-free, disease-progression, and death) to estimate lifetime costs and health benefits of adding darolutamide to ADT plus docetaxel. We fit Weibull, gamma, exponential, lognormal, and log-logistic parametric survival models to Kaplan Meier survival curves from the ARASENS trial. The Weibull model was selected based on AIC, visual inspection, and clinical plausibility. The cost of drugs and administration were obtained from IBM REDBOOK^® (darolutamide), CMS Drug Payment Table (docetaxel and leuprolide [ADT]), and CMS Physician Fee Schedule. The cost of clinical encounters for mHSPC, cost of progression, and utility values were sourced from published literature. A 3% discount rate per annum was applied to both costs and health outcomes. ICER in cost per QALY was the primary outcome measure while the willingness-to-pay (WTP) threshold was set at $150,000/QALY. Model robustness was assessed using one-way and probabilistic sensitivity analyses.

RESULTS: Compared to treatment with docetaxel plus ADT, the inclusion of darolutamide was associated with incremental QALYs and LYs of 0.86 and 0.89 respectively, at an additional cost of $567,500, yielding an ICER of $657,200 per QALY gained. The ICER was most sensitive to darolutamide cost and efficacy. Treatment with darolutamide was estimated to be cost-effective 50% of the time at a WTP of $500,000/QALY.

CONCLUSIONS: Despite demonstrating superior survival benefits, the addition of darolutamide to docetaxel and ADT may not be cost-effective for mHSPC treatment from a US healthcare sector perspective.