Study of the Antitumor Activity of Capecitabine in Combination With Erlotinib in Patients With Metastatic Colorectal Cancer

Approximately 150,000 people are diagnosed with colorectal cancer in the United States each year. Forty to fifty thousand people eventually will develop metastatic colorectal cancer and 40,000 people die annually because of advanced or metastatic colorectal cancer. Cancer patients prefer oral therapy over intravenous therapy as palliative treatment if efficacy regarding response rate and response duration is not compromised. Therefore, development of a completely oral combination therapy that approximates or improves upon the clinical outcomes attained by the reference triple drug therapies should be a research priority. Compared with intravenous 5-fluourouracil/leucovorin as first-line treatment for metastatic colorectal cancer, oral capecitabine has demonstrated similar survival outcomes (approximately 12-13 months), response rates (15-20%), and response durations (4-5 months) in two multi-institutional international randomized phase III trials. Erlotinib (OSI-774, Tarceva) is an orally available inhibitor of human EGFR tyrosine kinase. The epidermal growth factor receptor (EGFR) is overexpressed in a variety of human cancers including colorectal cancer. The principal goal of anticancer treatment with tyrosine kinase inhibitors such as erlotinib is to restore normal cellular growth by interrupting EGFR mediated cell proliferation and malignant The hypothesis of this phase II trial is that the unique mechanisms of action and non-overlapping toxicity profiles of capecitabine (Xeloda) and erlotinib will allow these drugs to be combined into a safe and tolerable regimen with better activity regarding response, response duration, and median survival than capecitabine alone in patients with previously untreated metastatic colorectal cancer.