352OEFFICACY AND SAFETY OF MAINTENANCE BEVACIZUMAB (BEV) WITH OR WITHOUT CAPECITABINE (CAP) AFTER INITIAL FIRST-LINE BEV PLUS DOCETAXEL (DOC) FOR HER2-NEGATIVE METASTATIC BREAST CANCER (MBC): IMELDA RANDOMISED PHASE III TRIAL

ABSTRACT Background: Until regulatory withdrawal of BEV–DOC in 2011, the combination was considered a valid first-line option for HER2-negative mBC based on results of a phase III trial [Miles, JCO 2010]. Progression-free survival (PFS) and response rate (RR) with first-line DOC (max 9 cycles) were significantly improved by adding BEV continued until disease progression (PD). The open-label randomised phase III IMELDA trial tested whether adding CAP to maintenance BEV continued until PD after initial BEV–DOC improves PFS. Methods: Patients (pts) with HER2-negative measurable mBC, ECOG PS Results: Between Jun 2009 and Mar 2011 (when enrolment was prematurely terminated) 284 pts were enrolled and treated; 185 (65%) were randomised. BEV (N = 94) BEV–CAP (N = 91) Median age, years (range) 54 (24–77) 49 (24–80) Triple-negative mBC, n (%) 21 (22) 25 (27) Visceral metastases, n (%)a 65 (69) 62 (68) ≥3 metastatic organs, n (%) 54 (57) 43 (47) Median duration of follow-up, months (range)b 30.4 (1.3–43.3) 31.6 (0.8–41.6) PFSb Events, n (%) 83 (88) 69 (76) HRc (95% CI) 0.38 (0.27–0.55) Log-rank p Median PFS, months 4.3 11.9 OSb Events, n (%) 53 (56) 33 (36) HRc (95% CI) 0.43 (0.26–0.69) Log-rank p Median OS, months 23.7 39.0 1-year OS rate, % (95% CI) 72 (61–80) 90 (82–95) Grade ≥3 AEsb, n (%) All 28 (30) 47 (52) Hand-foot syndrome 0 30 (33) Hypertension 3 (3) 8 (9) Proteinuria 4 (4) 4 (4) Gastroenteritis 3 (3) 0 aAt randomisation. bFrom randomisation. cStratified. Conclusions: Adding CAP to maintenance BEV provided statistically significant and clinically meaningful improvements in PFS (HR 0.38, p