Cabazitaxel Improves Outcomes in Metastatic CRPC Compared With Abiraterone or Enzalutamide

Compared with abiraterone or enzalutamide, cabazitaxel significantly improved clinical outcomes in patients with metastatic castration-resistant prostate cancer who previously received docetaxel plus abiraterone or enzalutamide (N Engl J Med. 2019 Sep 30. Epub ahead of print).

“The efficacy and safety of cabazitaxel, as compared with an androgen-signaling-targeted inhibitor (abiraterone or enzalutamide), in patients with metastatic castration-resistant prostate cancer who were previously treated with docetaxel and had progression within 12 months while receiving the alternative inhibitor (abiraterone or enzalutamide) are unclear,” explained Ronald de Wit, MD, Erasmus Medical Center, Rotterdam, the Netherlands, and colleagues.

Thus, Dr de Wit et al randomized 255 patients previously treated with docetaxel and abiraterone or enzalutamide to receive cabazitaxel 25 mg/m² intravenously every 3 weeks plus prednisone daily and granulocyte colony-stimulating factor (n = 129) or either 1000 mg of abiraterone plus prednisone or 160 mg of enzalutamide daily (n = 126).

The primary end point of the study was progression-free survival (PFS), and secondary end points included survival, response, and safety.

Follow-up lasted for a median of 9.2 months, at which point imaging-based progression or death was reported in 95 (73.6%) and 101 (80.2%) patients in the cabazitaxel and noncabazitaxel arms, respectively (hazard ratio [HR], 0.54; 95% CI, 0.40-0.73; P <.001). The median imaging-based PFS was 8.0 and 3.7 months, respectively.

The median rate of overall survival was 13.6 months in the cabazitaxel arm versus 11.0 months in the noncabazitaxel arm (HR for death, 0.64; 95% CI, 0.46-0.89; P = .008). The median PFS was 4.4 months and 2.7 months, respectively (HR for progression or death, 0.52; 95% CI, 0.40-0.68; P <.001), and a prostate-specific antigen response was observed in 35.7% and 13.5% of patients, respectively (P <.001). In addition, tumor response was noted in 36.5% and 11.5% of patients (P = .004).

Of note, grade ≥3 adverse events were reported in 56.3% of patients receiving cabazitaxel and in 52.4% of those who did not receive cabazitaxel. Dr de Wit and colleagues observed no new safety signals.

“Cabazitaxel significantly improved a number of clinical outcomes, as compared with…abiraterone or enzalutamide…in patients with metastatic castration-resistant prostate cancer…previously treated with docetaxel and…abiraterone or enzalutamide,” they concluded.—Hina Porcelli