The US Food and Drug Administration (FDA) has approved Erbitux (cetuximab), in combination with platinum-based chemotherapy with 5-fluorouracil (CT), for the first-line treatment of recurrent locoregional or metastatic squamous cell carcinoma of the head and neck (SCCHN).
The approval, which is based on data from the landmark EXTREME (ErbituX in first-line Treatment of REcurrent or MEtastatic head & neck cancer) trial, makes Erbitux plus CT the first treatment regimen approved in 30 years with extended overall survival in patients with recurrent locoregional or metastatic SCCHN.
Erbitux (cetuximab) is a monoclonal antibody (IgG1 Mab) designed to inhibit the function of a molecular structure expressed on the surface of normal and tumour cells called the epidermal growth factor receptor (EGFR, HER1, c-ErbB-1). In vitro assays and in vivo animal studies have shown that binding of ERBITU Erbitux GFR blocks phosphorylation and activation of receptor-associated kinases, resulting in induction of apoptosis (cell death), inhibition of cell growth, and decreased matrix metalloproteinase and vascular endothelial growth factor production. In vitro, Erbitux can mediate antibody-dependent cellular cytotoxicity (ADCC) against certain human tumor types. In vitro assays and in vivo animal studies have shown that Erbitux inhibits the growth and survival of tumour cells that express the EGFR. No anti-tumour effects of Erbitux were observed in human tumour xenografts lacking EGFR expression.
EXTREME, which was previously published in the New England Journal of Medicine, was a phase III open label, randomized, multi-centre, controlled trial. This study was conducted outside the US by Merck KGaA, Darmstadt, Germany, and used European Union (EU)-approved cetuximab. Erbitux provides approximately 22% higher exposure relative to the EU-approved cetuximab used in the EXTREME trial; these pharmacokinetic data, together with the results of the EXTREME trial and other clinical trial data establish the efficacy of Erbitux at the recommended dose. EXTREME showed that cetuximab plus CT in the first-line treatment of recurrent locoregional or metastatic SCCHN resulted in superior efficacy across clinically meaningful endpoints, including overall survival, progression-free survival, and objective response rate compared to CT. Cetuximab plus CT significantly extended patients’ median overall survival by 36% compared to patients who received CT alone (10.1 months vs. 7.4 months, respectively) [HR: 0.80; 95% CI: 0.64-0.98; p=0.034]. Cetuximab plus CT also significantly increased median progression-free survival by 67% (5.5 vs. 3.3 months, respectively) [HR: 0.57; 95% CI: 0.46-0.72; p<0.0001] compared to CT alone. A significant improvement in objective response rate was also demonstrated (36% vs. 20%, odds ratio, 2.33 [95% CI: 1.50-3.60]; p=0.0001).
Serious infusion reactions occurred with the administration of Erbitux in approximately 3 per cent of patients in clinical trials, with fatal outcome reported in less than 1 in 1000. Healthcare providers should immediately interrupt and permanently discontinue Erbitux infusion for serious infusion reactions. Cardiopulmonary arrest and/or sudden death occurred in 2 per cent of patients with squamous cell carcinoma of the head and neck treated in a clinical trial with Erbitux and radiation therapy and in 3 per cent of patients with squamous cell carcinoma of the head and neck treated with EU-approved cetuximab in combination with platinum-based therapy with 5-fluorouracil (5-FU) in the EXTREME trial. Healthcare providers should closely monitor serum electrolytes, including serum magnesium, potassium, and calcium, during and after Erbitux administration.
Bristol-Myers Squibb and Lilly are committed to supporting patient access to ERBITUX and have put in place a number of programmes to help patients and providers. Destination Access, which is a Reimbursement Support Program, helps patient access by providing benefits investigation support, prior authorization assistance, appeals assistance and patient assistance.