A randomized, multicenter phase III trial of bevacizumab plus capecitabine as maintenance treatment after initial treatment with bevacizumab plus XELOX in previously untreated metastatic colorectal cancer.

Abstract

474 Background: Colorectal cancer is one of the most frequent malignancies, second to breast cancer in women and third to lung cancer and prostate cancer in men. The aim of this study in first-line metastatic colorectal cancer (mCRC) was to achieve a better progression-free survival (PFS) and less risk of toxicity by administrating bevacizumab (BEV) + capecitabine + oxaliplatin (XELOX) for 6 cycles, stop oxaliplatin and go with maintenance therapy (BEV + capecitabine) until progression. Methods: BEV (7.5 mg/kg) + XELOX (capecitabine 1,000 mg/m2 bid d1–14 + oxaliplatin 130 mg/m2 d1 q3w) were administered until progression (Arm A) or 6 cycles of BEV + XELOX followed by BEV + capecitabine were administered until progression (Arm B). PFS was the primary endpoint; secondary endpoints included overall survival (OS), objective response rate (ORR), and safety. A sample size of 118 patients (pts) was calculated to achieve 80% power to detect an increase of 1.5 months in median PFS between Arm A (9.5 months) and Arm B (11.0 months) with a standard deviation of 3.9 months and significance level of 0.05 using a 10% drop-out rate. Results: A total of 122 pts were randomized. No significant differences were found in demographic characteristics between the two arms. Median treatment period was 6.1 (range 0.7–13.4) and 6.8 (range 0.7–12.4) months in Arms A and B, respectively. Interim analysis showed no statistically significant differences in median PFS and ORR between arms (see table). Tolerability was also acceptable in both arms with grade 3/4 diarrhoea in 7.7% vs. 8.2%, weakness in 15.2% vs. 8.4%, hand-foot syndrome in 6.3% vs. 9.4%, and neuropathy in 2.8% vs. 4.6% of pts in Arms A and B, respectively. Conclusions: BEV + capecitabine as maintenance therapy following induction BEV + XELOX is non-inferior to continuous BEV + XELOX until progression. While this study is ongoing, these interim findings suggest that maintenance therapy with BEV + capecitabine is an appropriate option following induction BEV + XELOX in pts with mCRC. [Table: see text] [Table: see text]