Latest Erbitux (cetuximab) data presented at the World Congress on Gastrointestinal Cancer (WCGIC) reinforce the value of the targeted therapy in the treatment of metastatic colorectal cancer (mCRC) patients with KRAS wild-type (wt) tumours. Results from the CRYSTALa and CELIMb trials have provided further evidence that KRAS mutation status is the current accepted standard predictive biomarker for Erbitux efficacy in patients with mCRC. In addition, new data have shown that the rash associated with Erbitux therapy can be effectively treated with a cream containing vitamin K.

"The data presented at WCGIC are a potent reminder of the significant efficacy demonstrated by Erbitux in the treatment of metastatic colorectal cancer and of the unique role it plays in the personalized treatment of patients with KRAS wild-type tumours, all of which underscores the need for every patient to be tested for KRAS status at diagnosis," said Dr Wolfgang Wein, executive vice president, Oncology, Merck Serono. "Moreover, this new evidence shows that the rash associated with EGFR-targeted agents can be effectively and economically treated, thereby further improving the already favourable tolerability of this therapy."

Erbitux personalizes cancer care by significantly improving response rates (RR) and progression-free survival (PFS) in patients with KRAS wild-type tumours

Latest results from the multi-centre, phase-III, randomized, controlled Crystal trial demonstrate that the addition of Erbitux to the standard Folfiri chemotherapy regimen resulted in a significantly improved RR (59.3 per cent vs. 43.2 per cent, p=0.003) and PFS (9.9 vs. 8.7 months; Hazard Ratio (HR)=0.68; p=0.017) compared to Folfiri alone in mCRC patients with KRAS wt tumours.

BRAF is located 'downstream' of KRAS in the EGFR signalling pathway targeted by Erbitux and a retrospective analysis was conducted to determine whether BRAF mutation status also plays a role in influencing Erbitux efficacy in mCRC patients. BRAF mutation was found to have occurred in only 5 per cent of the BRAF-evaluable population (529 patients), and therefore the clinical utility of this potential biomarker may be limited. KRAS is therefore currently the only predictive biomarker in the treatment of mCRC for which there is meaningful clinical evidence.

High response rate seen with Erbitux results in significantly improved resectability rates and greater potential for cure in patients with KRAS wild-type tumours.

Complete resection (R0) of liver metastases provides mCRC patients with the only possibility of a cure from the disease. Non-resectable metastases may become resectable following effective treatment with chemotherapy, or chemotherapy plus Erbitux.

Updated results from the Celim study presented at WCGIC demonstrate that the combination of Erbitux with chemotherapy resulted in a high RR in patients with KRAS wt mCRC (70 per cent). In a new analysis, a group of seven surgeons retrospectively conducted an independent, objective review of scans from 75 patients included in the CELIMb study. Resectability according to the scans increased significantly during the study from 32 per cent prior to the Erbitux treatment combination to 60 per cent after treatment (p<0.01).

Erbitux is a first-in-class and highly active IgG1 monoclonal antibody targeting the epidermal growth factor receptor (EGFR).