Waltham, MA – March 20, 2018 – Exosome Diagnostics, Inc., a developer of revolutionary, biofluid-based molecular diagnostics, recently published a study on the detection of the Epidermal Growth Factor Receptor (EGFR) T790M mutation in plasma from patients with Non-Small Cell Lung Cancer (NSCLC). The study, demonstrated superior sensitivity and specificity utilizing the company’s proprietary cGMP manufactured ExoLutionTM Plus kit, which co-isolates exosomal RNA/DNA and cfDNA (exoNA) in a single step followed by a qPCR based mutation detection assay. The paper, “Exosome-based Detection of EGFR T790M in Plasma from Non-Small Cell Lung Cancer Patients”, appears in the current online edition of Clinical Cancer Research, a journal of the American Association for Cancer Research.
About 60% of NSCLC patients develop resistance to EGFR inhibitor therapy due to the EGFR T790M mutation. Patients who fail therapy due to this mutation will benefit from treatment with osimertinib. However, performing a repeat lung biopsy to obtain the mutation status is challenging and cannot be done on all patients. Detection of EGFR T790M in a liquid biopsy would solve some of the issues, but it has proven difficult due to low abundance of T790M positive cell-free DNA in blood. This study identifies a non-invasive and highly sensitive alternative for the identification of this mutation, examining the combined plasma exoNA.
The study analyzed 210 patient plasma samples and achieved 92% sensitivity and 89% specificity for detection of EGFR T790M using tissue biopsy results as the gold-standard. A currently used liquid biopsy that utilizes cfDNA only (FDA approved cobas® EGFR Mutation Test v2) achieved a lower sensitivity of 58% and 80% specificity . In employing the exoNA based assay presented in the study, the number of unnecessary follow-up biopsies could be reduced from 42% (using cfDNA only) to 8% using the combined exosome platform.
“One of the main issues with liquid biopsies has been the very low copy numbers of the mutations on cfDNA, especially in intrathoracic disease or early-stage cancer. Our ExoLutionTM Plus platform efficiently captures both exosomes and cfDNA, and this publication is another example that the combined exoNA improves current liquid biopsy tests that look at cfDNA only. In a recent publication we showed that mutated EGFR copy numbers in exoNA are up to 10-fold higher compared to analysis of cfDNA alone,” says Johan Skog, Chief Scientific Officer and founding scientist of Exosome Diagnostics. “In addition, we are analyzing two biological processes since cfDNA is coming from the dying apoptotic/necrotic cells and exsomes from living cells,” concluded Skog.
“The sensitivity and specificity advantage of the Exosome Diagnostics platform provides a marked improvement for patient care within oncology,” stated John Boyce, President and CEO of Exosome Diagnostics. “Providing a highly sensitive and specific liquid biopsy solution where repeat biopsies are problematic for the patient, as in intrathoracic disease, will allow more frequent testing and will significantly improve the quality of patient care,” Boyce concluded.