Cetuximab is an immunoglobulin G1 (IgG1) chimeric monoclonal antibody against colorectal cancers that express epidermal growth factor receptor.
Dr Derek Jonker and colleagues from Canada evaluated 572 patients from 2003 to 2005.
The patients had colorectal cancer expressing immunohistochemically detectable epidermal growth factor receptors.
|Cetuximab was also associated with progression-free survival|
|New England Journal of Medicine|
The patients had been previously treated with a fluoropyrimidine, irinotecan, and oxaliplatin or had contraindications to treatment with these drugs.
The patients were randomized to an initial dose of 400 mg of cetuximab per square meter of body-surface area.
This was followed by a weekly infusion of 250 mg per square meter plus best supportive care in 287 patients, or best supportive care alone in 285 patients.
The team's primary end point was overall survival.
The researchers found that in comparison with best supportive care alone, cetuximab treatment was associated with a significant improvement in overall survival.
Cetuximab was also associated with progression-free survival.
The researchers found that these benefits were robust after adjustment in a multivariable Cox proportional-hazards model.
The median overall survival was 6 months in the cetuximab group, and 5 months in the group assigned to supportive care alone.
Partial responses occurred in 8% of patients in the cetuximab group, but in none in the group assigned to supportive care alone.
The disease was stable in an additional 31% of patients assigned to cetuximab, and in 11% of patients assigned to supportive care alone.
The team found that quality of life was better preserved in the cetuximab group, with less deterioration in physical function and global health status scores.
Cetuximab treatment was associated with a characteristic rash.
The researchers reported that a rash of grade 2 or higher was strongly associated with improved survival.
The team noted that the incidence of any adverse event of grade 3 or higher was 79% in the cetuximab group.
The incidence of any adverse event of grade 3 or higher was 59% in the group assigned to supportive care alone.
Dr Jonker's team concluded, "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."