A Genotype-guided Study of Irinotecan Administered in Combination With 5-fluorouracil/Leucovorin (FOLFIRI) and Bevacizumab in Advanced Colorectal Cancer Patients

This study is being done to determine the maximum dose of a certain chemotherapy drug (irinotecan) that can be tolerated as part of a combination of drugs. There is a combination of chemotherapy drugs typically used to treat cancer of the colon and rectum: 5-Flurouracil (5-FU), leucovorin, and irinotecan; the combination is known as FOLFIRI. At the present time, the Food and Drug Administration (FDA) has approved this drug combination for the treatment of cancers of the colon and rectum. The FDA has also approved the use of a drug called bevacizumab (or Avastin) in combination with FOLFIRI, and this is considered one of the standards of care for all patients with colon and rectal cancer which has spread. The best dose of irinotecan to use in the combination of FOLFIRI and bevacizumab is not known. Earlier studies have shown that higher doses of irinotecan can be used safely as part of the FOLFIRI combination, but it is unclear whether these same doses will be safe when bevacizumab is added to this combination.