Phase I/II study of bi-weekly XELIRI plus bevacizumab treatment in patients with metastatic colorectal cancer resistant to oxaliplatin-based first-line chemotherapy

We aimed to determine the recommended dose for bi-weekly XELIRI plus bevacizumab for second-line chemotherapy and examined its safety and efficacy in patients with metastatic colorectal cancer resistant to oxaliplatin-based first-line chemotherapy. Irinotecan and bevacizumab were administered as a continuous intravenous infusion on Day 1 at 150 mg/mm(2) and 5 mg/kg, respectively. Capecitabine was orally administered in two divided doses on Days 2-8. Each 2-week treatment cycle was defined as a single course of treatment. During Phase I, we determined the recommended dose for capecitabine. In Phase II trials, efficacy and treatment safety was verified (UMIN000003934). The recommended dose of capecitabine was determined to be 2000 mg/m(2). Median progression-free survival was 7.8 months [95% confidence interval (CI) 6.1-10.9 months], and median overall survival was 18.9 months (95% CI 11.6-28.4 months). Response rate was 17.4% (95% CI 6.4-28.3%). The most common Grade ae3 hematotoxic adverse events were anemia (10.9%), neutropenia (10.9%), and leukopenia (8.7%), while the occurrence rate of Grade ae3 non-hematotoxic adverse events was relatively low (< 10%). Bi-weekly XELIRI plus bevacizumab was found to be a safe and effective second-line treatment in patients with metastatic colorectal cancer resistant to oxaliplatin-based first-line chemotherapy.