OBJECTIVES

: The objective of the study was to determine abiraterone acetate + prednisone (AAP) treatment outcomes in the pre-chemotherapy real-world setting.

METHODS

: A multi-center (4), multi-country (3) retrospective chart review of adult men diagnosed with mCRPC receiving and progressing on androgen deprivation therapy (ADT) prior to treatment initiation with abiraterone no later than December 31, 2014. Summary statistics and Kaplan Meier curves were used to estimate treatment outcomes in months (m).

RESULTS

: The sites enrolled 168 patients, 132 were per protocol. Mean age was 77, with the highest mean age from the Norwegian site (79.5). Median treatment duration was shortest in Sweden (4.3 m and 6.4 m), longer in Denmark (8.6 m) and longest in Norway (13.9 m). Norway had the longest overall survival (OS) with 18.4 m and the longest progression free survival (PFS) with 7.5 m. Sweden had the shortest reported PFS (4 m and 5.1 m at each respective site) and shortest OS (4.9 m and 9.6 m). PFS for the Danish site was 5.1 m and OS 16.1 m.

CONCLUSIONS

: Real-life treatment use of AAP for pre-chemo mCRPC patients varied substantially in the Nordic countries during the study period. Patients offered AAP were generally old and frail during this period of observation closely following a new therapeutic launch. Most of the men initiating treatment were described as ineligible for chemotherapy. Compared to later real- world outcomes studies in Europe with patients taking AAP in this indication, including Swedish sites (Time-To-Progression 11.4 m)[1]), and Swedish registry data (treatment duration 10m, OS 25 m[2]), patient outcomes for this study period were worse, likely due to the underlying frailty status of the patient population chosen for this therapy when it was first introduced. A sequential cohort model, accounting for changes in practice in various time periods post-introduction, is recommended for future therapeutic follow-up.