393P - Efficacy of Eribulin in a Second-Line or Later Setting in Patients (Pts) with Metastatic Breast Cancer (Mbc): a Pooled Analysis

Abstract

ABSTRACT Aim: Eribulin (E) is under review by the European Medicines Agency for use as a second-line and later therapy for pts with locally advanced/MBC who have advanced after prior chemotherapy. To assess the efficacy of E in this setting, we conducted pooled analyses of data from 2 phase 3 open-label studies in pts with locally advanced/MBC. Methods: In study 1, pts who had received 0–2 chemotherapies for advanced disease were randomized 1:1 to E mesilate (1.4 mg/m2 iv on days 1 and 8 every 21 days) or capecitabine (1.25 g/m2 orally bid on days 1–14 every 21 days). In study 2, pts had received 2–5 chemotherapies, and were randomized 2:1 to E (as above) or treatment of physician's choice. For this analysis, overall survival (OS) was assessed by Cox regression and stratified log-rank tests for the overall intent-to-treat population and by HER2, HR and triple negative (TNBC) status. Results: In all, 1644 pts (median age 55.0 yrs) were included, most in the 2nd (35.8%) or 3rd (37.0%) -line settings for advanced disease. E significantly improved OS vs control in the overall, HER2 - , HR+ and TNBC groups (Table). Similar OS data were seen in the HR- and non-TNBC groups (data not shown). E significantly improved progression-free survival (PFS) overall (3.9 vs 3.2 months; HR: 0.88; 95%CI: 0.78, 0.98; p = 0.020), and for HER2- (3.7 vs 2.9 months; HR: 0.84; 95% CI: 0.73, 0.96; p = 0.009), HR+ (4.1 vs 3.5 months; HR: 0.85; 95% CI: 0.73, 0.98; p = 0.028) and TNBC (2.8 vs 2.5 months; HR: 0.76; 95% CI: 0.60, 0.97; p = 0.026) but not HER2+ pts (3.8 vs 4.2 months; HR: 1.0; 95%CI: 0.75, 1.35; p = 0.970). Overall HER2 - HER2 + HR + TNBC E Con E Con E Con E Con E Con n 946 698 663 497 150 104 574 432 199 153 Median OS,amonths 15.1 12.5 15.1 12.0 13.5 11.7 15.7 13.5 12.4 8.1 HR (95% CI)b 0.84 (0.76, 0.94) 0.84 (0.74, 0.96) 0.75 (0.57, 1.00 0.85 (0.74, 0.99) 0.70 (0.55, 0.86) pb 0.003 0.011 0.054 0.038 0.003 aBased on survival curves adjusted by study; bstratified by region, prior capecitabine use and study (and HER2 status for the overall group). E, eribulin; Con, control; HR, hazard ratio; OS, overall survival. Conclusions: In this pooled analysis, E significantly improved OS in a second-line or later setting vs available therapies in the overall, HER2 - , HR + , HR - , TNBC and non-TNBC groups. Treatment differences were not significant in HER2+ pts, but there were fewer pts. Eribulin was thus superior to available therapies in a second-line or later setting in pts with locally advanced/MBC who have advanced after ≥ 1 chemotherapy for advanced disease. Disclosure: C. Twelves: has disclosed a consultant or advisory role with Eisai for which he has been compensated. He has also received honoraria and other remuneration from Eisai; J. Cortes: has disclosed a consultant or advisory relationship with Novartis, Celgene and Roche for which he has been compensated. He has also received honoraria from Novartis, Celgene, Roche and Eisai; M. Olivo: Martin Olivo is an employee of Eisai Inc.; Y. He: Yi He is an employee of Eisai Inc. All other authors have declared no conflicts of interest.