The FDA has approved a new dosing regimen of 500 mg/m2 cetuximab (Erbitux®, Eli Lilly) for patients with KRAS wild-type epidermal growth factor receptor (EGFR)–expressing metastatic colorectal cancer (CRC) and patients with head and neck squamous cell carcinoma (HNSCC). This biweekly dosage regimen serves as an alternative to the existing weekly dosage regimen of cetuximab, whether on its own or combined with chemotherapy, and should be administered as a single 120-minute intravenous infusion every two weeks.
For KRAS wild-type, EGFR–expressing metastatic colorectal cancer, cetuximab is currently approved in combination with FOLFIRI (irinotecan/fluorouracil/leucovorin) as first-line treatment, in combination with irinotecan for patients whose disease is refractory to irinotecan–based chemotherapy, and as a single agent for patients who are intolerant of irinotecan or who have failed oxaliplatin– or irinotecan–based chemotherapy. For HNSCC, cetuximab is approved in combination with radiation therapy for first-line treatment of locally or regionally advanced disease, in combination with fluorouracil for first-line treatment of recurrent locoregional or metastatic disease, and as a single agent for patients with recurrent or metastatic disease who have failed prior platinum–based therapy.
Approval was based on population pharmacokinetic analyses, in which the predicted exposures of cetuximab 500 mg/m2 twice weekly were compared to the predicted exposures of cetuximab 250 mg once weekly. Among the trials studied were BONNER (NCT00968435) and EXTREME (NCT00122460) for HNSCC and CRYSTAL (NCT00154102) and Study CA225-025 (NCT00079066) for KRAS wild-type, EGFR–expressing metastatic CRC. The population pharmacokinetic analyses were supported by pooled analyses of overall response rates, progression-free survival, and overall survival.
In each of the exploratory analyses, the efficacy of cetuximab was consistent between the two dosage arms and supported the results of the pharmacokinetic modeling analyses.
The most common adverse reactions that occurred in at least 25% of patients receiving cetuximab were rash, pruritus, nail changes, headache, diarrhea, and infection. The prescribing information for cetuximab contains a warning that serious infusion reactions and cardiopulmonary arrest can occur with this medication.
For More Information
Clinicaltrials.gov (2020). Cetuximab + best supportive care compared with best supportive care alone in metastatic epidermal growth factor receptor-positive colorectal cancer. NLM identifier: NCT00079066.
Clinicaltrials.gov (2016). Bevacizumab, cetuximab, and cisplatin with IMRT (Intensity-Modulated Radiation Therapy) for patients with stage III/IV head and neck squamous cell carcinoma. NLM identifier: NCT00968435.
Clinicaltrials.gov (2014). Cetuximab (Erbitux) in combination with cisplatin or carboplatin and 5-fluorouracil in the first line treatment of subjects with recurrent and/or metastatic squamous cell carcinoma of the head and neck (EXTREME). NLM identifier: NCT00122460.
Image credit: Nephron. Licensed under CC BY-SA 3.0.