Irinotecan Hydrochloride With FOLFIRI and Cetuximab as First-Line Therapy in Treating Patients With RAS Wild-Type Colorectal Cancer

This phase I trial studies the side effects and the best dose of irinotecan hydrochloride, based on a genetic test, when given in combination with fluorouracil, leucovorin calcium, and cetuximab as first-line therapy in treating patients with an abnormal gene called RAS wild-type that has spread to other parts of the body (metastatic). Patients may also have a gene called uridine diphosphate glucuronosyltransferase (UGT1A1) that may interfere with the way irinotecan hydrochloride is absorbed by the body and may not be able to tolerate it. Determining the presence of this gene may help determine the best dose of irinotecan hydrochloride when given with fluorouracil and leucovorin calcium (FOLFIRI). Combination chemotherapy, such as FOLFIRI, works in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Cetuximab may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving FOLFIRI together with cetuximab may be a better treatment for patients with colorectal cancer.