Abiraterone Acetate Provides Survival Benefit in Post-Chemotherapy Setting

San Diego—In a retrospective cohort study conducted by Alice Dragomir, MSc, PhD, and colleagues, there was survival benefit among patients with metastatic castration resistant prostate cancer (mCRPC) receiving abiraterone acetate in combination with chemotherapy compared with patients receiving chemotherapy only. The researchers reported results of the study at the AUA 2016 Annual Meeting in a presentation titled Use of Abiraterone Acetate in the Management of Castration Resistant Prostate Cancer: A Real-Life Cost Effectiveness Study.

Abiraterone acetate was introduced in 2012 in Quebec for management of patients with mCRPC in the post-docetaxel setting. The current study was designed to examine the cost-effectiveness of abiraterone acetate management of mCRPC in a real-life setting in Quebec.

The researchers utilized Quebec public healthcare administration databases. The cohort included 191 patients with mCRPC who received chemotherapy from 2009 to 2010, and 303 patients who received abiraterone acetate from 2012 to 2013 (defined as abiraterone overall). Patients in the abiraterone group were stratified into two groups: abiraterone post-chemotherapy (n=99) and abiraterone without prior chemotherapy (n=204).

Survival was evaluated using a comparison of the abiraterone groups with the chemotherapy only group. The incremental cost-effectiveness ratio (ICER) was determined by dividing changes in primary therapy costs and survival in the two study periods.

In the abiraterone overall group, there was a 2- and 5-month survival increment in the abiraterone overall group (hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.64-1.1; P=.021) and in the abiraterone post-chemotherapy group (HR, 0.68; 95% CI, 0.47-0.98; P=.004) compared with the chemotherapy only group. However, there was no difference in survival in the abiraterone without prior chemotherapy group compared with the chemotherapy only group.

Total mCRPC medication costs on average were $11,541 in the chemotherapy only group and approximately $30,000 in the abiraterone groups. The ICER per life year gained was $69,627 for the abiraterone post-chemotherapy group and $117,140 for the abiraterone overall group.

In conclusion, the researchers said, “Our real-life study indicates that patients receiving abiraterone overall or in the post-chemotherapy setting had a survival benefit when compared to the group receiving only chemotherapy. The addition of abiraterone was associated with an important ICER, which was increased in the abiraterone overall group due to the reduced efficacy found in patients receiving abiraterone without prior docetaxel.”

Source: Dragomir A, Rocha J, Aprikian A, Vanhuyse M, Cury F, Kassouf W. Use of abiraterone acetate in the management of castration resistant prostate cancer: a real-life cost effectiveness study. Abstract of a presentation at the American Urological Association 2016 Annual Meeting, May 8, 2016, San Diego, California.