Scott Berry

BACKGROUND: Cetuximab, an IgG1 chimeric monoclonal antibody against epidermal growth factor receptor (EGFR), has activity against colorectal cancers that express EGFR. METHODS: From December 2003 to August 2005, 572 patients who had colorectal cancer expressing immunohistochemically detectable EGFR and who had been previously treated with a fluoropyrimidine, irinotecan, and oxaliplatin or had contraindications to treatment with these drugs underwent randomization to an initial dose of 400 mg of cetuximab per square meter of body-surface area followed by a weekly infusion of 250 mg per square meter plus best supportive care (287 patients) or best supportive care alone (285 patients). The primary end point was overall survival. RESULTS: In comparison with best supportive care alone, cetuximab treatment was associated with a significant improvement in overall survival (hazard ratio for death, 0.77; 95% confidence interval [CI], 0.64 to 0.92; P=0.005) and in progression-free survival (hazard ratio for disease progression or death, 0.68; 95% CI, 0.57 to 0.80; P<0.001). These benefits were robust after adjustment in a multivariable Cox proportional-hazards model. The median overall survival was 6.1 months in the cetuximab group and 4.6 months in the group assigned to supportive care alone. Partial responses occurred in 23 patients (8.0%) in the cetuximab group but in none in the group assigned to supportive care alone (P<0.001); the disease was stable in an additional 31.4% of patients assigned to cetuximab and in 10.9% of patients assigned to supportive care alone (P<0.001). Quality of life was better preserved in the cetuximab group, with less deterioration in physical function and global health status scores (both P<0.05). Cetuximab treatment was associated with a characteristic rash; a rash of grade 2 or higher was strongly associated with improved survival (hazard ratio for death, 0.33; 95% CI, 0.22 to 0.50; P<0.001). The incidence of any adverse event of grade 3 or higher was 78.5% in the cetuximab group and 59.1% in the group assigned to supportive care alone (P<0.001). CONCLUSIONS: Cetuximab improves overall survival and progression-free survival and preserves quality-of-life measures in patients with colorectal cancer in whom other treatments have failed. (ClinicalTrials.gov number, NCT00079066 [ClinicalTrials.gov].).

Importance: Combining biologic monoclonal antibodies with chemotherapeutic cytotoxic drugs provides clinical benefit to patients with advanced or metastatic colorectal cancer, but the optimal choice of the initial biologic therapy in previously untreated patients is unknown. Objective: To determine if the addition of cetuximab vs bevacizumab to the combination of leucovorin, fluorouracil, and oxaliplatin (mFOLFOX6) regimen or the combination of leucovorin, fluorouracil, and irinotecan (FOLFIRI) regimen is superior as first-line therapy in advanced or metastatic KRAS wild-type (wt) colorectal cancer. Design, Setting, and Participants: Patients (≥18 years) enrolled at community and academic centers throughout the National Clinical Trials Network in the United States and Canada (November 2005-March 2012) with previously untreated advanced or metastatic colorectal cancer whose tumors were KRAS wt chose to take either the mFOLFOX6 regimen or the FOLFIRI regimen as chemotherapy and were randomized to receive either cetuximab (n = 578) or bevacizumab (n = 559). The last date of follow-up was December 15, 2015. Interventions: Cetuximab vs bevacizumab combined with either mFOLFOX6 or FOLFIRI chemotherapy regimen chosen by the treating physician and patient. Main Outcomes and Measures: The primary end point was overall survival. Secondary objectives included progression-free survival and overall response rate, site-reported confirmed or unconfirmed complete or partial response. Results: Among 1137 patients (median age, 59 years; 440 [39%] women), 1074 (94%) of patients met eligibility criteria. As of December 15, 2015, median follow-up for 263 surviving patients was 47.4 months (range, 0-110.7 months), and 82% of patients (938 of 1137) experienced disease progression. The median overall survival was 30.0 months in the cetuximab-chemotherapy group and 29.0 months in the bevacizumab-chemotherapy group with a stratified hazard ratio (HR) of 0.88 (95% CI, 0.77-1.01; P = .08). The median progression-free survival was 10.5 months in the cetuximab-chemotherapy group and 10.6 months in the bevacizumab-chemotherapy group with a stratified HR of 0.95 (95% CI, 0.84-1.08; P = .45). Response rates were not significantly different, 59.6% vs 55.2% for cetuximab and bevacizumab, respectively (difference, 4.4%, 95% CI, 1.0%-9.0%, P = .13). Conclusions and Relevance: Among patients with KRAS wt untreated advanced or metastatic colorectal cancer, there was no significant difference in overall survival between the addition of cetuximab vs bevacizumab to chemotherapy as initial biologic treatment. Trial Registration: clinicaltrials.gov identifier: NCT00265850.