Eribulin plus trastuzumab in pretreated HER2-positive advanced breast cancer patients: safety and efficacy. An Italian experience

BACKGROUND: Chemotherapy plus targeted therapy is the established treatment for human epidermal growth factor receptor 2 (HER2)–overexpressing breast cancer (BC). Limited data regarding the safety and activity of the combination of eribulin and trastuzumab (E/T) in pretreated HER2-positive advanced BC (ABC) are available. The aim of this observational, retrospective, multicenter study was to examine the tolerability and the clinical activity of E/T in this setting. METHODS: Patients treated with eribulin mesylate plus standard dose of trastuzumab were included. Data on overall response rate (ORR), progression-free survival (PFS), overall survival (OS), and safety were reported. RESULTS: Between October 2012 and November 2015, 24 consecutive patients with HER2-positive ABC were included. All patients were heavily pretreated: the median number of prior chemotherapy regimens for ABC was 3 (range 2–9). The median number of cycles with E/T was 11.5 (range 2–26). The ORR was 41.7%. Median PFS was 5.4 months, median postprogression survival was 5.4 months, and median OS was 8 months. Neutropenia was the most common grade 3/4 clinical adverse event (16.7%). CONCLUSIONS: Tolerability and clinical activity of the E/T combination schedule are encouraging. The results of this study indicate that this combination might be considered for treatment of pretreated HER2 ABC.