A Phase ll Study of Oxaliplatin, Capecitabine, and Bevacizumab in the Treatment of Metastatic Esophagogastric Adenocarcinomas

The number of new cases of esophageal and gastric cancers in the United States in 2005 is 14520 for esophageal cancer and 21860 for gastric cancer. Unfortunately, esophageal and gastric cancers will also account for 13570 and 11550 deaths, respectively, in 2005. The 5 year survival rates for metastatic gastroesophageal, GE junctional, and gastric cancers are less than 5%. The major current treatment modality for patients with advanced esophageal, GE junctional, and gastric adenocarcinomas is systemic chemotherapy.

We seek to investigate the efficacy of capecitabine and oxaliplatin in combination with bevacizumab as first line treatment for metastatic esophagogastric cancers. The choice of capecitabine and oxaliplatin is made to develop a user-friendly biologically-based regimen, offering patients oral capecitabine in place of continuous 5FU infusion pumps. Since capecitabine can be given crushed this regimen may both be active and user-friendly. Preliminary data in colorectal cancer suggest that the regimen of capecitabine, oxaliplatin, and bevacizumab has comparable activity to FOLFOX-bevacizumab. The goal of the proposed regimen is to define a capecitabine and oxaliplatin-based regimen that optimizes biological approaches over cytotoxic approaches. The addition of bevacizumab to chemotherapy regimens for metastatic colorectal cancer, metastatic non-small cell lung cancer, and metastatic breast cancer has shown to improve response rates and overall survival. If active, this regimen could serve as a first line comparator to the capecitabine, oxaliplatin, and epirubicin combination. This approach will also help to simplify regimen development across gastrointestinal cancers.

In addition to the primary efficacy endpoint of this protocol, several correlative endpoints will also be examined in an exploratory manner. The importance of developing blood-based and tumor biomarkers has been extensively reviewed. However, the role of such predictive markers has not been well studied for XELOX-A. This information is important since it may help define which populations are most likely to benefit and most likely to suffer significant toxicity from this important GI cancer regimen. This biomarker approach may also help understand and define mechanisms of sensitivity, resistance, and toxicity that may be used to guide future hypothesis-driven studies designed to improve the efficacy and safety of this regimen. The correlative biomarker endpoints include serum, plasma and urine biomarkers (e.g. VEGF and bFGF), a wound healing model of angiogenesis, and tumor biopsy studies .