OBJECTIVE - To calculate costs per median overall survival (OS) month in chemotherapy-naïve patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone acetate plus prednisone (AA+P) or enzalutamide.
METHODS - Median treatment duration and median OS data from published Phase 3 clinical trials and prescribing information were used to calculate costs per median OS month based on wholesale acquisition costs (WACs) for patients with mCRPC treated with AA+P or enzalutamide. Sensitivity analyses were performed to understand how variations in treatment duration and treatment-related monitoring recommendations influenced cost per median OS month. Cost effectiveness estimates of other Phase 3 trial outcomes were also explored: cost per month of chemotherapy avoided and per median radiographic progression-free survival (rPFS) month.
RESULTS - The results demonstrated that AA+P has a lower cost per median OS month than enzalutamide ($3,231 vs. 4,512; 28% reduction), based on the following assumptions: median treatment duration of 14 months for AA+P and 18 months for enzalutamide, median OS of 34.7 months for AA+P and 35.3 months for enzalutamide, and WAC per 30-day supply of $8,007.17 for AA+P versus $8,847.98 for enzalutamide. Sensitivity analyses showed that accounting for recommended treatment-related monitoring costs or assuming identical treatment durations for AA+P and enzalutamide (18 months) resulted in costs per median OS month 8% to 27% lower for AA+P than for enzalutamide. Costs per month of chemotherapy avoided were $4,448 for AA+P and $5,688 for enzalutamide, while costs per month to achieve median rPFS were $6,794 for AA+P and $7,963 for enzalutamide.
CONCLUSIONS - This cost effectiveness analysis demonstrated that costs per median OS month, along with costs of other Phase 3 trial outcomes, were lower for AA+P than for enzalutamide. The findings were robust to sensitivity analyses. These results have important implications for population health decision makers evaluating the relative value of therapies for mCRPC patients.
Journal of medical economics. 2016 Mar 31 [Epub ahead of print]
Dominic Pilon, Mary Kay Queener, Patrick Lefebvre, Lorie A Ellis
a Groupe d'analyse, Ltée , Montréal , QC , CAN., b Janssen Scientific Affairs, LLC , Horsham , PA , USA., a Groupe d'analyse, Ltée , Montréal , QC , CAN., b Janssen Scientific Affairs, LLC , Horsham , PA , USA.