Ixabepilone in metastatic breast cancer: Real-world experience

Abstract

Objective: This study assessed the efficacy of ixabepilone and compared two regimens of this drug (weekly vs. every 3 weeks) in patients with heavily treated metastatic breast cancer during daily clinical practice. Material and Methods: Between 2012 and 2018, all cases of metastatic breast cancer treated with ixabepilone were evaluated. Results: We evaluated data from 75 patients diagnosed with metastatic breast cancer. Eighty-eight percent of patients had hormone-positive Human Epidermal Growth Factor Receptor 2-negative metastatic breast cancer. Most patients had visceral and bone metastases (65%). Most patients were heavily pretreated, 96% had received at least three lines of prior chemotherapy in the metastatic setting. The median use of ixabepilone was the sixth line. The objective response rate was 32%. Patients had a median progression-free survival (PFS) of 4 months, and there was no statistical difference in the PFS of two chemotherapy regimens (weekly: 3.2 months vs. every 3 weeks: 5 months, p=0.31). Patients had a median overall survival (OS) of 12.7 months, and there was no statistical difference in the OS of two chemotherapy regimens (weekly: 16 months vs. every 3 weeks: 12 months, p=0.91). The incidence of Grade 1-2 hematologic toxicity events (neutropenia and thrombocytopenia) was 10% in patients on the weekly reg-imen. Grade 3 neutropenia was seen in 20% of patients and grade 3 thrombocytopenia was seen in 6% of patients treated every 3 weeks. Con-clusion: This study showed that ixabepilone is effective in patients with heavily treated breast cancer, and weekly treatment is less toxic and safer than treatment every 3 weeks for these patients. © 2022 Elsevier B.V., All rights reserved.