LAUSR

Abstract Objective Eribulin treatment improved overall survival with predictable toxicities in phase 3 trials of patients with previously treated, locally advanced/metastatic breast cancer. This study (NCT02443428) prospectively observed eribulin‐treated patients in real‐world clinical practice. Methods This observational multicentre registry study enrolled 76 patients with locally advanced/metastatic breast cancer who had ≤2 prior chemotherapeutic regimens for advanced disease. Eribulin was administered at a 1.23 mg/m2 dose (days 1 and 8 of every 21‐day cycle). Adverse events (AEs) were monitored and effectiveness was assessed per local practice. Results AEs occurred in 98.7% of patients; 88.2% had eribulin‐related AEs. The most common AEs were fatigue (64.5%), alopecia (36.8%), nausea (35.5%) and constipation (30.3%). Serious AEs occurred in 42.1% of patients. The most common grade 3/4 AEs were neutropenia (9.2%), febrile neutropenia (9.2%), dyspnoea (5.3%) and pleural effusion (5.3%). No fatal AEs occurred. Dose reductions occurred in 31.6% of patients, 42.1% experienced dose delays and 9.2% discontinued due to worsening condition. There were complete responses in 2.6% and partial responses in 15.8% of patients. Median time to progression and overall survival were 4.0 and 8.3 months, respectively. Conclusion Eribulin was well tolerated in real‐world clinical practice, comparable to safety and effectiveness reported in other clinical trials.