ERBITAG: Non-interventional study on the efficacy of cetuximab in first-line therapy in patients with RAS wild-type metastatic colorectal cancer

Metastatic colorectal cancer (mCRC) is a difficult-to-treat disease with poor clinical outcomes. Systemic chemotherapy in combination with targeted anti-EGFR therapy has expanded the treatment options for mCRC. However, the therapeutic efficacy of anti-EGFR regimens and relevant prognostic factors vary according to age, performance status and tumor location. The non-interventional ERBITAG study was performed to evaluate the efficacy and safety of cetuximab in first-line therapy in RAS WT mCRC patients under routine clinical practice. ERBITAG is a non-interventional study of wild-type (WT) RAS mCRC patients initiating a first-line therapy with cetuximab from 2010 to 2018. Overall survival (OS) and progression-free survival (PFS) were analyzed using the Kaplan-Maier methods. χ²-test was used to compare selected categorial variables. Of a total of 728 patients included, baseline characteristics were: median 67 years, male sex 69%, ECOG performance status ≤ 1 81.3%, left-sided tumors 64.5%, liver metastasis 73.4% and prior hepatic metastasis resection before cetuximab-based treatment 16.4%. Median PFS was 10.9 months, median OS was 23.6 months and ORR was 58.0%. Resection rate of liver and/or lung metastases under cetuximab-based therapy was 13.9% and 18.9% of liver metastases. The most common treatment-emergent event (TEAE) was acne-like rash (all grades: 46.8%; grade 3–4: 4.7%). Subgroup analysis showed better outcomes in younger patients (ORR, OS), patients with left-sided tumors (ORR, PFS, OS) and lower grade tumors (ORR, PFS, OS), patients with resected liver and/or lung metastases (PFS, OS) and patients with treatment breaks (OS). Skin prophylaxis with systemic antibiotics and/or topical steroids (ORR, OS, PFS) was associated with better outcomes. The ERBITAG study provides insights into the use of cetuximab in a large RAS WT mCRC cohort in real-life clinical practice in Germany. Cetuximab in combination with first-line chemotherapy demonstrates clinical outcomes and safety data similar to results from the other pivotal randomized controlled trials. Study Number: EMR062202-515 (https://www.pei.de/SharedDocs/awb/nis-0101-0200/0114.html) Registered on 04-MAY-2010.