Efficacy and safety of eribulin in HER2-negative metastatic breast cancer: the results of long-term experience in real clinical practice in Russia

Aim. The aim of the study is to examine the efficacy and safety of eribulin in HER2-negative metastatic breast cancer (BC) in Russian clinical practice. Materials and methods. The analysis included 459 patients with advanced BC from 44 federal and municipal medical clinics in Russia and received at least 2 courses of treatment with eribulin in accordance with the registered indications for drug. The average age of women was 56 years (between 29 and 81 years), 83% of patients had HER2-negative tumor subtype (49.9% - luminal BC and 33.1% - triple-negative BC) HER2-positive biological tumor subtype was registered in 17% of patients. Visceral metastases were diagnosed in 73% of patients and three-zone and multiple zone metastases were diagnosed in 41.6% of cases. The median number of prior lines of therapy in patients with disseminated disease was 2; anthracycline and taxane chemotherapy was applied in 94.3% of patients, and 38.1% of patients were recived CT plus capecitabine. Standard treatment regimen with eribulin was cotinuing (1.4 mg/m² as a 2-5-minute intravenous infusion administrated on days 1, 8 of a 21-day cycle) until disease progression, unacceptable toxic effects, or impossibility of the drug administration for any other reason. We estimated the efficacy and safety of treatment with eribulin in Russian patients with HER2-negative BC. Results. Objective response rate was achieved in 20.5% of cases, complete response rate was in 3.2%, partial - 17.3%, and the stable disease rate was marked in 52.7% of women, and in 19.7% of these cases was prolonged more than 6 months. The frequency of objective response was higher in luminal BC group compared with triple-negative BC: 23.5% vs 15.8%; tumor growth control 76.9% vs. 67.8%, respectively; p