P-0242 Xelox and Bevacizumab as First-Line Treatment in fit Elderly Patients with Metastatic Colorectal Cancer: The Boxe Study

Introduction The addition of bevacizumab to oxaliplatin-based chemotherapy significantly improved progression-free survival (PFS) in patients with metastatic colorectal cancer (MCRC). However, clinical trials have been conducted primarily in younger patients with only a small proportion of elderly patients. Moreover, an increased risk of arterial thromboembolic events has been observed in some trials in older patients. This phase II study was designed to evaluate the efficacy and safety of XELOX (capecitabine plus oxaliplatin) plus bevacizumab in fit patients over 70 years of age with MCRC. Methods Treatment consisted of bevacizumab 7.5mg/Kg and oxaliplatin 130mg/m2 on day 1, plus capecitabine 1000mg/m2 twice daily on days 1-14, every 3 weeks up to a maximum of 8 cycles. Patients with a clinical response or stable disease could be maintained on bevacizumab monotherapy up to progressive disease. The primary study end-points were safety and response rate. Results A total of 44 patients were recruited. In an intention-to-treat analysis, the overall response rate was 52% [95% confidence interval (CI): 37% to 68%], with 86% of patients achieving disease control. Median PFS and overall survival were 11.5 months (95% CI: 10.0-12.9 months) and 19.3 months (95% CI: 16.5-22.1 months), respectively. Four patients (9%) underwent liver metastasectomy with curative intent. In all, 10 patients (23%) had grade 3/4 adverse events (AEs), the most common being peripheral neuropathy (7%), stomatitis (7%), diarrhoea (7%). No patients died because of treatment-related AEs. The low incidence of bevacizumab-associated AEs (hypertension, thromboembolic events and gastrointestinal perforation) was not consistent with that of previous reports in elderly patients. Conclusion XELOX plus bevacizumab is effective and has a manageable tolerability profile when administered to fit elderly patients with MCRC.