Highest Sensitivity Liquid Biopsy Test Introduced for Lung Cancer

Approximately 20% of non-small cell lung cancer (NSCLC) patients test positive for an epidermal growth factor receptor (EGFR) driver mutation and receive EGFR Tyrosine Kinase Inhibitor (TKI) therapy, but unfortunately, most will develop a resistance to this type of therapy.

Tissue biopsies are the current standard for identifying T790M resistance. The T790M mutation results in an amino acid substitution at position 790 in EGFR, from a threonine (T) to a methionine (M). This mutation occurs within exon 20, which encodes part of the kinase domain. If a patient tests positive, they are eligible for treatment with a second line EGFR TKI therapy. Unfortunately, a tissue biopsy is not always a viable option for a large percentage of these patients.

Non-invasive liquid biopsies have emerged as a viable alternative for patients unable to have tissue biopsy procedure. Exosome Diagnostics Inc. (Cambridge, MA, USA) have presented data that sets a new standard for EGFR-T790M resistance mutation detection in lung cancer, with the highest sensitivity reported to date. This test is being developed to improve care and outcomes for the large population of patients who can benefit from second line EGFR TKI therapy but are missed with currently available tissue and liquid biopsy tests.

Clinical studies have demonstrated that the US Food and Drug Administration (Silver Springs, MD, USA) approved cobas test for liquid biopsy, only identifies 59% of patients who will respond to a second line EGFR TKI therapy. This is a direct result of lack of sensitivity and inability to test challenging intrathoracic disease. By analyzing exosomal ribonucleic acid (exoRNA) and cell free tumor DNA (ctDNA) from the same sample Exosome Dx addresses current limitations by identifying 96% of the T790M positive population, with no loss of sensitivity in patients with intrathoracic disease. ExoDx Lung (T790M) has been optimally designed for ExosomeDx’s high throughput biomarker testing platform that is being deployed in 2017.

Johan Skog, PhD, Chief Scientific Officer of Exosome Diagnostics, said, “This study further demonstrates the power of our ExoLution Plus platform that combines exoRNA plus ctDNA. This result was not surprising since we have shown superior performance to ctDNA across several disease states in blinded head to head studies. Clinical samples are precious so we are thrilled to be able to offer a more sensitive test that take both exoRNA and ctDNA into consideration.” The study was presented at the AACR-EORTC-NCI meeting held November 29 to December 2, 2016, in Munich, Germany.

Related Links:
Exosome Diagnostics
US Food and Drug Administration