Phase II study of a novel taxane (Cabazitaxel-XRP 6258) in previously treated advanced non-small cell lung cancer (NSCLC) patients

Purpose: Given the success of cabazitaxel in patients with prostate cancer who progressed after receiving prior chemotherapy, its preclinical efficacy in various cell lines and possible ability to cross blood-brain barrier, cabazitaxel was hypothesized to increase objective response rate (ORR) in second-line setting in non-small cell lung cancer (NSCLC). Methods: This was a phase II 2-stage trial in 28 patients using two different treatment schedules (A: 20 mg/m² every 3 weeks intravenously and B: 8.4 mg/m² intravenously weekly) to determine the ORR of cabazitaxel with secondary end points including progression-free survival (PFS), safety, and overall survival (OS). Results: There was one objective response in schedule B. PFS and OS of schedule A was 3 and 6 months, respectively. PFS and OS of schedule B was 3 and 13 months, respectively. The stable disease rate was higher in schedule A (SD = 69.23 %; 95 % CL 38.57, 90.90) as compared to schedule B (SD = 38.46 %; 95 % CL 13.86, 68.42), but this difference was not statistically significant (P value = 0.1156). There were two grade 5 toxicities from sepsis. Hematuria of any grade developed in greater percentage of patients (35%) as compared to previous cabazitaxel phase 3 trial and led to change in our protocol. Conclusions: Response to cabazitaxel in NSCLC was not as robust as seen in prostate cancer and not superior to currently used agents such as docetaxel, pemetrexed, and erlotinib. In absence of significant objective responses, the second stage of the study was not undertaken.