PCN46 Cost-Efficacy Analysis of Licensed Drugs for the Treatment of Metastatic Castrate Resistant Prostate Cancer Post Docetaxel Based on Hospital Drug Evaluation Methodology in Spain

Abstract

To estimate which is the dominant treatment between the only two drugs that had been able to demonstrate overall survival (OS) improvements in patients with metastatic castrate resistant prostate cancer (mCRPC) that have progressed on or after docetaxel treatment, and that were approved by the EMA in 2011 (AA by accelerated procedure): cabazitaxel (CBZ) and abiraterone acetate (AA),. We replicated the methodology most commonly used by Spanish hospitals to estimate the cost-efficacy of oncologic drugs (OS gains and incremental costs vs. those of comparators) by: (i) taking the perspective of the Spanish NHS (ii) estimating treatment costs based on the product labels (i.e. main medication, co-medication, premedication, and primary prophylaxis) at ex-factory prices, and the cost of administering such medications; and (iii) the OS data from the respective pivotal phase III trials: for CBZ vs. mitoxantrone + prednisone (MP) OS was 15.1 vs. 12.7 months. For AA vs. placebo + prednisone (PP) OS was 15.8 vs. 11.2. Input for the base case analysis comes from Phase III randomized clinical trials and from publicly available cost data. Sensitivity analysis was performed on: (i) length of treatment; (ii) median OS; and (iii) G-CSF usage and drug administration costs. In our base case scenario the cost per cycle of CBZ was 4,711.52€ vs. 78.20€ for MP. The cost per cycle of AA was 3,179.26€ vs. 11.85€ for PP. Treatment costs difference for CBZ vs. MP is 27,799.93€ (range 13,665.36€ – 46,646.01€) and for AA vs. PP is 25,386.71€ (range 12,669.65€ - 38,103.76€). OS gain is 2.4 months for CBZ and 4.6 months for AA. In Spain, based on local hospital methodology, AA would be the dominant alternative (higher OS gain and lower incremental cost) to treat mCRPC patients that have progressed on or after a docetaxel based regime.