The impact of the number of prior androgen receptor pathway inhibitors before cabazitaxel treatment in patients with metastatic castration-resistant prostate cancer.

Objective: Cabazitaxel (CAZ) has been shown to prolong overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC) following docetaxel treatment. However, the impact of the number of prior androgen receptor pathway inhibitors (ARPIs) on CAZ efficacy remains unclear. This study aimed to analyze the effectiveness of CAZ based on the number of prior ARPIs administered before CAZ treatment.

Methods: A retrospective review was conducted on mCRPC patients who received CAZ. The differences in CAZ efficacy based on the number of prior ARPIs were evaluated and prognostic factors for prostate-specific antigen (PSA) progression-free survival (PFS) and OS were analyzed.

Results: A total of 59 patients were categorized into three groups: 12 patients with no prior ARPI, 26 with one prior ARPI, and 21 with two or more prior ARPIs. The median number of CAZ cycles and relative dose intensity were 5% and 60%, respectively. No significant differences were observed in PSA response or PFS among the three groups. Although OS from the first CAZ administration did not significantly differ among the groups, the OS from mCRPC diagnosis was shorter in the group with no prior ARPI. Multivariate analysis identified a time to mCRPC diagnosis of less than 11 months and low serum hemoglobin levels before CAZ administration as significant prognostic factors of poor OS following CAZ treatment.

Conclusions: PSA response, PFS, and OS after CAZ administration did not significantly differ based on the number of prior ARPIs. CAZ efficacy appears consistent regardless of the number of prior ARPI sequences.