A Phase II Study of High-Dose Cetuximab plus Irinotecan in Colorectal Cancer Patients with KRAS Wild-Type Tumors Who Progressed after Standard Dose of Cetuximab plus Irinotecan

Objectives: We conducted a phase II clinical trial of high-dose cetuximab plus irinotecan in KRAS wild-type patients who progressed on standard-dose cetuximab plus irinotecan. Methods: Patients who progressed within 4 weeks from receiving a minimum of 6 weeks of standard-dose cetuximab plus irinotecan were included in this study. Cetuximab was administered at 500 mg/m(2)/week and irinotecan was administered at the same dose/schedule on which each individual patient had previously progressed. The study was closed early after having met its primary end point. Results: Twenty patients were treated. The regimen was found to be efficacious, with 9 patients achieving disease control lasting more than 12 weeks. The median progression-free survival and overall survival were 2.8 and 6.6 months, respectively. The toxicity profile was favorable, with the exception of grade 3-4 hypomagnesemia which was noted in 25% of patients. Conclusions: High-dose cetuximab plus irinotecan rechallenge can re-elicit clinical benefits in patients who have previously failed cetuximab plus irinotecan treatment. The clinical benefits are modest and may be related to cetuximab rechallenge rather than cetuximab dose escalation. Copyright (C) 2013 S. Karger AG, Basel