Cabazitaxel does not prolong overall survival (OS) in patients with chemotherapy-naïve metastatic castration-resistant prostate cancer (mCRPC) compared with the first-line chemotherapy agent docetaxel, according to a trial published in The Journal of Clinical Oncology.

Data from previously conducted studies demonstrated that cabazitaxel may significantly improve OS once administered after initial docetaxel therapy. The authors investigated the potential of cabazitaxel as a first-line chemotherapeutic agent for patients with mCRPC. 

In the phase 3 FIRSTANA trial (ClinicalTrials.gov Identifier: NCT01308567), researchers randomly assigned 1168 chemotherapy-naïve patients with mCRPC 1:1:1 to receive intravenous (IV) cabazitaxel 20 mg/m2 (C20), cabazitaxel 25 mg/m2 (C25), or docetaxel 75 mg/m2 (D75) every 3 weeks with daily prednisone.

Patient characteristics at baseline were well balanced across the various treatment arms. The primary end point of the study was OS.

The study showed that median OS was 24.5 months for C20, 25.2 months for C25, and 24.3 months for D75. The hazard ratio (HR) for C20 vs D75 was 1.01 (95% CI, 0.85-1.20; P =.997). The HR for C25 vs D75 was 0.97 (95% CI, 0.82-1.16; P =.757).

Treatment-related grade 3 to 4 adverse events (AEs) occurred in 41.2%, 60.1%, and 46.0% of patients in C20, C25, and D75, respectively. The treatment arm receiving C25 reported higher incidence of febrile neutropenia, diarrhea, and hematuria, and the treatment arm receiving D75 reported high incidence of peripheral neuropathy, peripheral edema, alopecia, and nail disorders.

The final results of the study show that cabazitaxel is not superior to docetaxel in improving OS. The authors concluded that the similarity between the 2 agents however, “may offer additional flexibility to prescribing physicians with regard to treatment choices for individual patient-specific profiles in men with neuropathy, edema, or other conditions that may be preferentially exacerbated by docetaxel.”

Reference

1. Oudard S, Fizazi K, Sengelov L, et al. Cabazitaxel versus docetaxel as first-line therapy for patients with metastatic castration-resistant prostate cancer: a randomized phase III trial – FIRSTANA [published online July 28, 2017].  J Clin Oncol. doi: 10.1200/JCO.2016.72.1068