Study of Erbitux (Cetuximab) in Patients With Metastatic Colorectal Carcinoma

This is a phase II, multicenter, target enrollment of 250 evaluable patients, open-label study of cetuximab in patients with refractory, metastatic colorectal carcinoma. Based on prior studies, we predict that 70 to 75% of patients will be EGFR-positive. Patients must have documented failure after receiving either at least two chemotherapy regimens for metastatic disease or adjuvant therapy plus one chemotherapy regimen for metastatic disease provided that the patient progressed within 6 months of completing adjuvant therapy. Prior chemotherapy must have included irinotecan, oxaliplatin, and a fluoropyrimidine. Patients will receive an initial dose of cetuximab, 400 mg/m2, intravenously (i.v.) over 120 minutes, followed by weekly treatment with cetuximab, 250 mg/m2 i.v. over 60 minutes. Patients who experience unacceptable toxicity or who have progressive disease will not receive further cetuximab therapy. Patients will be evaluated for a tumor response at a minimum of every 6 weeks while on cetuximab therapy. Patients with stable disease or a partial or complete response may continue to receive weekly cetuximab therapy, unless they are dose-delayed or discontinued because of toxicity. Patients who have a partial or complete response must have a confirmatory tumor assessment no less than 4 weeks after the initial evaluation demonstrating a response. In addition, there is a pharmacokinetic companion protocol which will determine the trough and peak levels of cetuximab in 25 patients enrolled in the study at four to eight centers. A pharmacologic serum sample for the determination of levels of cetuximab will be obtained prior to the initial, fourth and sixth cetuximab infusions and 1 hour following the completion of the initial, fourth and sixth cetuximab infusions in the first course; and prior to and 1 hour post the completion of the first cetuximab infusion of each subsequent course of therapy. A course of therapy is defined as six weekly infusions of cetuximab monotherapy. ImClone will perform the pharmacokinetic analyses.