Clinical outcomes of patients with metastatic breast cancer treated with eribulin: A realworld evidence study from China

e13126 Background: Eribulin is a novel synthetic analog of halichondrin B that acts as a microtubule inhibitor and inhibits the G2-M growth phase. Eribulin was approved for metastatic breast cancer (MBC) based on the landmark phase 3 EMBRACE trial (Cortes et al, Lancet 2011; NCT00388726); however, only a small number of Asian patients were included in that trial. Therefore, in this real-world study, we retrospectively assessed the clinical outcomes of Chinese patients with MBC who received eribulin. Methods: Adult patients with MBC who received eribulin as several lines of therapy were retrospectively analyzed. Socio-demographic, clinical, pathology, imaging, and therapy records were reviewed. Progression-free survival (PFS) and tumor response were evaluated. Results: A total of 85 patients were included. The median age was 45 years (range, 21–63). Eribulin was used as a first, second, third, and fourth or more chemotherapy agent in 13 (15.3%), 16 (18.8%), 11 (12.9%) and 45 (52.9%) of patients with MBC, respectively. Eribulin was monotherapy in 32.9% of patients; eribulin plus anti-HER2 targeted therapy was used in 9.4% of patients; eribulin plus immunotherapy was used in 5.9% of patients; eribulin plus other chemotherapy was used in 36.5% of patients, and eribulin plus antiangiogenic therapy was used in 9.4% of patients. The objective response rate (ORR) was 28.2% overall. By number of lines of therapy, the first-line ORR was 38.5% and the second-line ORR was 37.5%. On subgroup analysis, ORR of patients with liver metastasis and lung metastasis was 43.9% and 38.6 %, respectively. By molecular classification, the ORR of patients with HR+/HER2− disease was 66.7%; among patients with HER2+ disease, 32.6%; and among patients with triple-negative BC, 13.3%. The 6-month PFS rate was 33.6% overall. By number of lines of therapy, the 6-month PFS rate among patients who received eribulin as first-line treatment was 67.7% and among patients who received eribulin as second-line treatment, 38.3%. Among patients who received eribulin monotherapy, the 6-month PFS rate was 21.4% and among patients who received eribulin combination therapy, 41.2%. No adverse reactions related to neutrophils were reported. Conclusions: This real-world retrospective study suggests that eribulin was effective in Chinese patients with MBC with a range of prior lines of chemotherapy, supporting the use of eribulin in the treatment of Chinese patients with MBC.