Phase II Trial of Cetuximab in Combination With Fluorouracil, Leucovorin, and Oxaliplatin in the First-Line Treatment of Metastatic Colorectal Cancer

Abstract

Purpose: This phase II study investigated the efficacy and safety of cetuximab combined with standard oxaliplatin-based chemotherapy (infusional fluorouracil, leucovorin, and oxaliplatin [FOLFOX-4]) in the first-line treatment of epidermal growth factor receptor–expressing metastatic colorectal cancer (mCRC). Patients and Methods: The activity of cetuximab plus oxaliplatin was investigated in colon cancer cell lines and xenograft models. In the clinical study, patients with mCRC received on day 1 of a 14 day cycle, cetuximab (initial dose 400 mg/m² during week 1, then 250 mg/m² weekly) followed by FOLFOX-4 (oxaliplatin 85 mg/m² on day 1; leucovorin 200 mg/m² on days 1 and 2, followed by fluorouracil 400 mg/m² bolus then 600 mg/m² intravenous infusion during 22 hours on days 1 and 2). Results: The preclinical studies confirmed the supra-additive activity of cetuximab to oxaliplatin. In the clinical study, 43 patients were included, with a median age of 65 years (range, 43 to 78 years). Response rates (RRs) were 79% (unconfirmed) and 72% (confirmed), with 95% disease control. Median progression-free survival (mPFS) and median duration of response were 12.3 and 10.8 months, respectively. Ten patients (23%) underwent resection with curative intent of previously unresectable metastases. After a median follow-up of 30.5 months, median overall survival (mOS) was 30.0 months. Cetuximab did not increase the characteristic toxicity of FOLFOX-4 and was generally well tolerated. Conclusion: Cetuximab in combination with FOLFOX-4 is a highly active first-line treatment for mCRC, showing encouraging RR, mPFS, and mOS values. The treatment resulted in a high resectability rate, which could potentially result in an improved cure rate. This combination is under phase III development.