Abstract 735: Sensitive detection of ctDNA in early stage non-small cell lung cancer patients with a personalized sequencing assay
Authors: Heider Katrin , Gale Davina , Ruiz-Valdepenas Andrea , Marsico Giovanni , Sharma Garima , Perry Malcolm , Osborne Robert , Howarth Karen , Lazarus Tadd , Rundell Viona , Belic Jelena , Wulff Jerome , Harden Susan , Rassl Doris M. , Rintoul Robert C. , Rosenfeld Nitzan 
Published: September 2020

Abstract
Introduction
Identification of minimal residual disease (MRD) following curative intervention of localized non-small cell lung cancer (NSCLC) holds promise for identifying patients who are at higher risk of relapse and who would benefit from adjuvant treatment. Current routine clinical practice involves serial radiographic imaging following surgery to detect macroscopic disease. Liquid biopsy can identify patients who have MRD without macroscopic disease. Currently available assays have only identified circulating tumor DNA (ctDNA) in a limited number of cases with early stage NSCLC. More sensitive methods are needed to accurately identify the majority of patients who will relapse. Here we evaluate the performance of InVision®MRD, a personalized sequencing assay for plasma cell-free DNA, for detection of ctDNA in patients with early-stage NSCLC undergoing treatment with curative intent.
Methods
InVision®MRD is a highly sensitive in vitro diagnostic assay, currently available for research use only (RUO), that can detect the presence of tumor DNA traces in cell-free DNA from plasma samples of cancer patients. InVision®MRD identifies tumor-specific variants from exome sequencing of tumor tissue and tracks them in plasma specimens by multiplex PCR and high-depth next-generation sequencing. We evaluated the detection of ctDNA in plasma samples collected from the LUng cancer - CIrculating tumor DNA (LUCID) study, which collected plasma samples from 100 patients with NSCLC stages I-III who underwent radical treatment with curative intent, either surgery or radiotherapy ± chemotherapy. Of patients in the LUCID study, 60% had stage I NSCLC and 40% patients had stage II/III disease, according to TNM 7th edition.
Results
To evaluate the InVision®MRD assay, a subset of samples from the LUCID study were analyzed. Samples were collected before and after surgery and chemo-radiotherapy from patients with early-stage NSCLC. Using multiplexed analysis of 48 patient-specific variants and high-depth sequencing, ctDNA was detected in 50% of pre-treatment samples analyzed from the first set of 18 patients, at ctDNA fractions ranging from 20 ppm (equivalent to 0.002%) to 19576 ppm (equivalent to 1.958%).
Conclusions
These findings highlight an opportunity to improve ctDNA detection for early stage NSCLC using a patient-specific plasma sequencing assay. Initial detection rates have reached 50% for patients with early-stage disease prior to treatment, including detection of ctDNA to levels as low as a few parts per million. Together with further data to be presented, this suggests a possible route to improving treatment for early stage NSCLC by detection of residual disease post treatment and for monitoring for early detection of relapse.
Citation Format: Katrin Heider, Davina Gale, Andrea Ruiz-Valdepenas, Giovanni Marsico, Garima Sharma, Malcolm Perry, Robert Osborne, Karen Howarth, Tadd Lazarus, Viona Rundell, Jelena Belic, Jerome Wulff, Susan Harden, Doris M. Rassl, Robert C. Rintoul, Nitzan Rosenfeld. Sensitive detection of ctDNA in early stage non-small cell lung cancer patients with a personalized sequencing assay [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 735.