BIOC: ASCO abstract validating Biocept concept for lung cancer
Clinical validation and utility of a liquid biopsy for non-small cell lung carcinoma utilizing CTCs and ctDNA to analyze ALK, ROS and EGFR status.
Author(s): Veena M. Singh, Vassilios Alexiadis, Tim Watanaskul, Edgar Salas, Lan Huynh, Christine Mitchell, Romeo Fauni, Lyudmila Bazhenova, Lyle Arnold; Biocept, Inc, San Diego, CA; Biocept, San Diego, CA; UC San Diego Moores Cancer Center, La Jolla, CA
Abstract Disclosures
Abstract:
Background: A liquid biopsy in addition to clinical utility in a setting of insufficient tissue biopsy and offering better representation of all regions of a tumor to offset tumoral heterogeneity seen in a tissue biopsy, affords a real-time monitoring option to assess biomarker status in patients with non-small cell lung carcinoma. Methods: Biocept, Inc has two key technologies that harness the maximum benefit of a liquid biopsy utilizing both CTCs and ctDNA for biomarker analysis in NSCLC patients in a CLIA laboratory setting. Using a unique microchannel device, CTCs are enriched more than 20,000 fold, stained, enumerated and analyzed for biomarkers using Immunocytochemistry and FISH. After the capture and enumeration of CTCs , ALK and ROS1 gene rearrangements in tumor cells are analyzed using FISH. Additionally, a highly sensitive ctDNA assay, Target-Selector is employed, capable of detecting as low as a single mutant copy in a vast excess of normal sequences. The analytical performance of a T790M Target-Selector assay, has been demonstrated to detect mutant level as low as 1:40,000 relative to normal wild-type copies. Results: Concordance rates of 80-100 % were observed between the tissue and liquid biopsy. In one clinical case, a lung tumor tissue biopsy at presentation was T790M negative, and subsequent testing of the patient’s plasma after clinical progression detected an emergent T790M mutation by utilization of the Target-Selector assay analyzing ctDNA. A significant percentage of T790M mutated sequences were found. After a re-biopsy, the patient was confirmed to be T790M positive and has been entered into the Clovis CO1686 trial. Conclusions: Liquid Biopsy holds great potential and value to supplement standard solid tumor biopsies and for subsequent serial monitoring of biomarker status after therapy and/or clinical progression
