Analysis and Monitoring CTCs and ctDNA in CSF Demonstrates Clinical Concordance in Tesevatinib Treated NSCLC Patients with LM

2018 World Conference in Lung Cancer 1 1 2 2 2,3 2 Session P1.01 Advanced NSCLC Veena M. Singh , Cecile Rose T. Vibat , Masha V. Poyurovsky , Laurie S. Green , Beth MacGillivray , and David A. Eiznhamer Poster #: 11339 1Biocept, Inc., San Diego, CA, USA; 2Kadmon Corporation, LLC, New York, NY, USA; 3Present Address: NovusLife, LLC, Walton, MA Background ctDNA and CTC Analyses from a Single Specimen Results Results Liquid biopsy using blood has emerged as a non- CSF collections from 20 NSCLC patients with LM All LM Patients: CSF CTC and Biomarker Detection invasive and economical method to assess cancer DNA Isolation from were obtained at baseline. When possible, CSF was biomarkers. Applying liquid biopsy methods to evaluate CSF Supernate or blood plasma collected after 14 and 56 days of tesevatinib Patients Patients with Biomarker cerebrospinal fluid (CSF) is less well documented and Tested Detectable Detection provides key information to supplement routine therapy. For a subset of 8 patients, blood was also (N) Biomarkers Rate cytology in patients with brain metastases or collected prior to tesevatinib treatment. leptomeningeal metastases (LM). Current first line CTCs Detected at tyrosine kinase inhibitor (TKI) therapy of non-small cell qPCR Mutation Mutation Confirmation Pretreatment tesevatinib CTC counts were higher in ≥ 1 Time Point 20 17 85.0% lung cancer (NSCLC) patients with activating EGFR Detection by Sanger Sequencing CSF vs. blood in 75% (6 of 8) patients with both EGFR Gene mutations, exhibits poor penetration to the central ctDNA collections. Amplification Workflow nervous system (CNS). About 28% of patients treated Detected at ≥ 1 with erlotinib or gefitinib progress with CNS In 3 of 5 patients with baseline or emergent T790M Time Point 20 7 35.0% involvement. Here we present liquid biopsy evaluation Antibody Cocktail ctDNA in CSF, detection paralleled progression; EGFR Activating of circulating tumor cells (CTCs) and circulating tumor Isolate CTC Isolation T790M emerged after tesevatinib therapy in the Mutation at First DNA (ctDNA) in the CSF of NSCLC patients with LM, CSF Cell Pellet or patient whose CTCs decreased at progression. CTC Buffy Coat from Blood Available Time who were treated with the TKI, tesevatinib (KD019-206 CTC enumeration mirrored response to therapy, Point 20 19 95.0% clinical trial). Workflow decrease of symptoms, or progression in 11 of 13 Methods patients where CTCs were present and sufficient CSF or Blood clinical information was available. Serial CSF CTC Conclusions CSF samples were collected in patented tubes validated Collection in Patented Tube and ctDNA analyses were consistent with the overall to preserve CTCs for up to 96 hours and ctDNA for up clinical course of disease. to 8 days. The platform utilized in this work for CTC • Dual platform liquid biopsy technology for CSF capture and biomarker analysis employs a 10 antibody analysis demonstrates highly sensitive detection of capture cocktail targeting a wide spectrum of CTC Detection, CSF CTC Detection: Baseline and All Time Points both CTCs and mutant ctDNA in NSCLC patients Enumeration and phenotypes. CTC capture and identification of both Biomarker Analysis in with LM. cytokeratin positive (epithelial) and cytokeratin Patented Microchannel • negative (mesenchymal, stem cell) CTCs were CSF results were highly concordant with tissue undertaken in a patented microchannel. The Specimens Specimens with CTC analysis and clinical course of disease. quantitative ctDNA platform incorporates switch- FISH Analysis: Tested Detectable Detection CNV • Serial monitoring of CSF with CTCs and ctDNA can blockers, real time PCR and sequencing to detect a (N) CTCs Rate be utilized to evaluate drug response and disease mutant allele frequency down to 0.05% against progression, providing pertinent, wildtype. CTC analyses included enumeration and EGFR vital information for disease gene amplification status determination; ctDNA testing Baseline 20 16 80.0% FISH = Fluorescence in situ Hybridization management and care of was used to detect EGFR activating mutations L858R CNV = Copy Number Variation and Exon19 deletions, as well as the T790M resistance All Time Points 48 38 79.0% LM patients. mutation.