OBJECTIVES : The aim of this analysis was to evaluate the cost-effectiveness of olaparib in comparison with control treatment (enzalutamide or abiraterone) for metastatic castration resistant prostate cancer (mCRPC) patients with at least one genetic mutation in BRCA1, BRCA2, or ATM. The study was from the US payer perspective.

METHODS : A three states Markov model with progression-free, progressive disease and death was constructed to assess the health and economic outcomes. Base parameters were originated from the PROfound clinical trial (NCT02987543). The costs of drugs, disease management and treatment of serious adverse events were derived from RED BOOK, Centers for Medicare & Medicaid Services (CMS), and Healthcare Cost and Utilization Project (HCUP), respectively. Other direct medical expenditure and utility value were sourced from published literature. A 3% annual discount rate was used for all outcomes and the willingness-to-pay (WTP) threshold was set as $200,000/QALY. The primary outcomes of the model included quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs). Sensitivity analyses and scenario analyses were conducted to explore the impact of uncertainties and assumptions on the results.

RESULTS : The base case result indicated that olaparib gained additional 0.31 QALYs in compared with control treatment, and the ICER was $248,248 per QALY. One-way sensitivity analyses showed that the price of olaparib was the most influential parameter. The cost-effectiveness acceptability curves manifested that the acceptability of olaparib and control treatment were 54.8% and 45.2% respectively at $200,000/QALY WTP threshold. In scenario analyses, the ICER was below the WTP threshold by applying a 20% discount on the price of olaparib.

CONCLUSIONS : Olaparib treated for mCRPC patients with at least one genetic mutation in BRCA1, BRCA2, or ATM was not cost-effective in comparison with enzalutamide or abiraterone from the US payer perspective. Olaparib would be cost-effective when its price down-regulated by 20%.