Real-world experience in advanced NSCLC using FDA approved NGS CDx.

Abstract

e14602 Background: The number one challenge in clinical biomarker testing for non-small cell lung cancer (NSCLC) has been the sample adequacy, given that the majority of patients are diagnosed based on minimally invasive sampling of tumor tissue. The increasingly evolving integration of high-throughput next-generation sequencing (NGS) has redefined molecular diagnostic lab practice allowing for time- and cost-efficient parallel testing of multiple biomarkers with limited specimen. Two NGS companion diagnostic (CDx) tests have been approved by FDA, FoundationOne CDx (F1CDx) and Oncomine Dx Target Test (Oncomine Dx), but with different sample acceptance criteria. The minimum tumor content requirement for F1CDx is 20% while it is 10% for Oncomine Dx. The surface area requirement for F1CDx is 25mm2 while there is no required minimum surface area for Oncomine Dx. The difference in sample acceptance criteria may have a major impact on the number of advanced NSCLC patient samples that can be accepted and tested successfully, affecting biomarker-directed therapy. Methods: The analysis of 153 NSCLC patient samples tested by Oncomine Dx at Cancer Genetics, Inc. CLIA-certified and CAP-accredited lab from October 2017 to September 2018 evaluated the sample acceptance rate, biomarker results, and testing turn-around time (TAT). Results: Based on the data, a significant portion of the samples submitted for routine clinical testing consists of extremely small specimen, including FNA cytology, with 42% less than 1mm2. 83% of samples are acceptable by Oncomine Dx criteria, compared to 14% by F1CDx. Of the 82 samples that would not be acceptable by F1CDx but generated results by Oncomine Dx, 5 were positive for EGFR exon 19 deletions and L858R, 1 for BRAF V600E, 1 for a ROS1 fusion, and the remaining 35 were positive for other actionable alterations. Average TAT was 9.2 days, consistent with recommendation by IASLC/AMP/CAP guideline of within 10 days. Conclusions: The real-world routine clinical testing of NSCLC patient samples demonstrated that a higher number of specimens with limited tumor tissue could be tested with the FDA-approved NGS CDx Oncomine Dx providing rapid TATs, actionable insights, and impacting the patient treatment outcomes.