Real-life Data on First- and Second-Line Treatment of Metastatic Castration-Resistant Prostate Cancer With Abiraterone, Enzalutamide and Cabazitaxel – A multicentric Study From Portugal

Introduction and objectives

New drugs for metastatic castrate resistant prostate cancer (mCRPC) were approved, first in the pos-docetaxel and then in the pre-docetaxel setting. We aim to assess the real daily practice benefit of abiraterone (Abi), enzalutamide (Enz) and cabazitaxel (Cab) in patients with mCRPC, compare it with RCT results and compare Abi vs Enz.

Materials and methods

We retrospectively collected the data of all consecutive mCRPC patients treated with Abi, Enz or Cab in the six major oncological hospitals in the north of Portugal until December 2020.

Results

A total of 470 treatments pre-docetaxel (163 Abi and 307 Enz) and 373 pos-docetaxel (160 Abi, 148 Enz and 59 Cab) were included, with median follow-up time of 35 months. Mean age was 73.1, 84.4% had ECOG status < 2, ISUP grade was ≥ 4 in 59% and 28.0% had oligometastatic disease. In first line, for Abi and for Enz respectively, the proportion of patients with PSA reduction > 50% was 64.4% and 80.4% (P < .001), the mean duration of treatment (DT) was 10 and 14 months (P = .037) and the median overall survival (OS) was 25 months and 30 months (P = .17). In second line the results for Abi, Enz and Cab were respectively: proportion of patients with PSA reduction > 50% was 40.4%, 57.4% and 24.6% (p for Abi vs Enz=0.004); DT was 7, 8, and 3 months (p for Abi vs Enz = 0.27); OS was 17, 22 and 10 months (p for Abi vs. Enz = 0,07).

Conclusion

These drugs have good efficacy in real-world evidence, similar to those reported in randomized clinical trials, with the expected exception of lower OS due to the inclusion of a broader sample of patients. Our results add to the evidence that Enz might have better efficacy in this setting compared with Abi.