Phase 2 study of cabazitaxel as second-line treatment in patients with HER2-negative metastatic breast cancer previously treated with taxanes—a Hellenic Cooperative Oncology Group (HeCOG) Trial

Abstract

Background Cabazitaxel is a novel taxane that might be active in breast cancer resistant to first-generation taxanes. Methods The purpose of the current multicentre phase II trial was to evaluate the activity and safety of cabazitaxel, as second-line treatment, in patients with human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC) previously treated with taxanes. The primary endpoint was objective response rate (ORR). Results Eighty-four patients were enrolled between October 2012 and November 2016. Taxane resistance to previous treatment was detected in 43 cases. The ORR was 22.6% in the intent-to-treat population, 23.3% in taxane-resistant and 20.5% in taxane-non-resistant cases. At a median follow-up of 39.6 months, the median progression-free survival and overall survival were 3.7 months (95% CI 2.2–4.4) and 15.2 months (95% CI 11.3–19.4), respectively. Regarding toxicity, grade 3–4 neutropenia was reported in 22.6% and febrile neutropenia in 6% of the patients, respectively. Two fatal events (one febrile neutropenia and one sepsis) were reported as being related to study treatment. Conclusions This phase II trial suggests that cabazitaxel is active as second-line treatment in taxane-pretreated patients with HER2-negative MBC, with manageable toxicity.