MicroRNA-31-3p Expression is a Predictive Biomarker of Anti-EGFR Efficacy in Patients with RAS Wild-type Metastatic Colorectal Cancer

October 9th, 2018

Advanced ColoRectal Cancer (CRC) is often incurable and standard chemotherapy when combined with anti EGFR (Epidermal Growth Factor Receptor) targeted monoclonal antibodies such as VECTIBIX® (Panitumumab) and ERBITUX® (Cetuximab) as well as anti VEGF agent AVASTIN® (Bevacizumab), have demonstrated improvement in Progression Free Survival (PFS) and Overall Survival (OS). The benefit with anti EGFR agents however is only demonstrable in patients with metastatic CRC, whose tumors do not harbor RAS mutations. It is now becoming clear that among these pan RAS wild type tumors, a predictive biomarker, MiR-31-3p expression in tumors, may further determine who would benefit from Anti-EGFR targeted therapy.
In a recently published study (Clin Cancer Res 2018), tumors with Low MiR-31-3p expression benefited from ERBITUX® combination compared to AVASTIN® for PFS (HR=0.74;P=0.05), OS (HR=0.61;P<0.01) and Objective Response Rate (P<0.01). There was however no difference in outcomes among High MiR-31-3p expressors between the two treatment groups. This study suggested that only low MiR-31-3p expressing tumors among the pan RAS wild type CRC patients benefit from Anti-EGFR targeted therapies.