Contact Us

EGFR

Multiplexed assays simultaneously measure a large number of different protein markers. (View larger image)

The epidermal growth factor receptor (EGFR) is a drug target for both small molecule and antibody therapeutics. It has been approved in non small-cell lung carcinoma (NSCLC) and colorectal carcinoma (CRC) among other indications. These drugs block receptor signaling though blockade of the tyrosine kinase domain, or through inhibition of ligand binding. Current genomic tests measure receptor amplification, RNA levels, the mutation status of receptor or pathway molecules (EGFR or kRAS mutations) but no current assay can directly assess the activation state of the EGFR or its downstream signaling pathway components. Indeed, EGFR mutation-positive NSCLC tumors (thought to be constitutively active) show a high response rate to TKI therapy, but the many non-responders (50% or more) attest to the limitation of genomic analysis.

Since activation of EGFR is necessary for the response to these targeted agents, measuring levels of receptor activation and downstream signaling may help determine tumor responsiveness to EGFR targeted therapies in these patients.

Expression Pathology has developed a panel of new diagnostic assays that measure the activation of EGFR and key downstream signaling proteins through quantitation of the phosphorylation state of these proteins. These assays are based on the Liquid Tissue®-SRM technology platform. This approach enables absolute quantification of proteins and their phosphorylation status directly in FFPE tissue.

More information