Bevacizumab (BEV) plus second-line taxane (TAX) or other chemotherapy (CT) for triple-negative breast cancer (TNBC): Subgroup analysis of RIBBON-2.

Abstract

290 Background: In three randomized trials in the first-line metastatic breast cancer (MBC) setting, combining BEV with CT significantly improved progression-free survival (PFS; primary endpoint) and objective response rate (ORR) vs. CT alone. BEV also showed a significant PFS benefit in the second-line MBC setting (RIBBON-2) when combined with TAX or other CT. We analyzed data from the subgroup of patients (pts) with TNBC in RIBBON-2. Methods: Eligible pts had MBC that had progressed on first-line CT without BEV. Second-line CT (TAX, gemcitabine, capecitabine, or vinorelbine) was chosen before 2:1 randomization to CT with either BEV (10 mg/kg q2w or 15 mg/kg q3w) or placebo (PLA). All pts could receive BEV at progression. The primary endpoint was PFS. Results: RIBBON-2 included 684 pts; 159 (23%) had TNBC and of these, 67 (42%) received TAX with BEV/PLA. Baseline characteristics were broadly similar in the two treatment arms. In an exploratory analysis of pts with TNBC, BEV + CT led to significantly improved PFS and ORR vs. CT alone, and a trend toward improved overall survival (OS). The magnitude of the effect was particularly pronounced in pts receiving TAX CT. Conclusions: Pts with TNBC derive significant ORR and PFS benefit from BEV combined with second-line CT. Despite the small sample size, there was a trend (HR 0.624; p = 0.0534) toward OS benefit in pts treated with BEV, especially with TAX CT. [Table: see text]