On April 6, the U.S. Food and Drug Administration (FDA) approved a new dosage regimen for cetuximab (Erbitux) of 500 mg/m2 as a 120-minute intravenous infusion every 2 weeks for patients with KRAS wild-type, EGFR-expressing colorectal cancer or squamous cell carcinoma of the head and neck. This approval provides for a biweekly dosage regimen option in addition to the previously approved weekly dosage regimen for the approved indications when cetuximab is used as a single agent or in combination with chemotherapy.
The approval was based on population pharmacokinetic modeling analyses that compared the predicted exposures of cetuximab at 500 mg every 2 weeks to observed cetuximab exposures in patients who received cetuximab at 250 mg weekly. The application was also supported by pooled analyses of overall response rates, progression-free survival, and overall survival from published literature in patients with colorectal cancer and squamous cell carcinoma of the head and neck, and overall survival analyses using real-world data in patients with colorectal cancer who received either the weekly cetuximab or every-2-week regimens.
In these exploratory analyses, the observed efficacy results were consistent across dosage regimens and supported the results of the population pharmacokinetic modeling analyses. The most common adverse reactions (incidence ≥ 25%) to cetuximab were cutaneous adverse reactions (including rash, pruritus, and nail changes), headache, diarrhea, and infection.
For additional safety and efficacy information, and recommended dosage regimens, view the full prescribing information for cetuximab.