A phase I/II study of XELIRI plus bevacizumab as second-line chemotherapy for Japanese patients with metastatic colorectal cancer (BIX study).
BACKGROUND
Capecitabine is used mainly with oxaliplatin to treat metastatic colorectal cancer (mCRC). Results from capecitabine plus irinotecan (XELIRI) with or without bevacizumab (BV) have been reported in Europe but not in Japan. Consequently, the safety and efficacy of XELIRI plus BV in Japanese patients with mCRC were assessed in a single-arm phase II study.


METHODS
Eligible patients had had prior chemotherapy containing BV for mCRC and wild-type or heterozygous UGT1A1. Therapy in each 21-day treatment cycle consisted of capecitabine (800 mg/m(2) twice daily on days 1-15), irinotecan (200 mg/m(2) on day 1), and BV (7.5 mg/kg on day 1). The primary endpoint was dose-limiting toxicity in phase I and progression-free survival (PFS) in phase II.


RESULTS
A total of 34 patients (6 in phase I, 28 in phase II) were enrolled from May 2010 to June 2011. Baseline characteristics included a median age of 60 years (range: 22-74 years) for 24 men and 10 women. No dose-limiting toxicities appeared in phase I. Median PFS was 240 days (95% confidence interval: 179-311 days). Overall response rate was 18.1%, and the disease-control rate was 90.9%. The incidence of adverse events frequently associated with irinotecan and capecitabine were neutropenia (any grade, 55.9%; grade 3 or 4, 11.8%), diarrhea (any grade, 50%; grade 3 or 4, 5.9%), and hand-foot syndrome (any grade, 61.8%; grade 3 or 4, 5.9%).


CONCLUSION
Our results suggest that XELIRI plus BV is well tolerated and effective as a second-line treatment for mCRC in Japanese patients. This regimen could be especially appropriate for patients resistant to oxaliplatin-based regimens.