Guardant360® test results may provide prognostic information beyond the detection of actionable biomarkers for ALK-rearranged NSCLC patients

May 30, 2020

SINGAPORE — According to the data presented at the American Society of Clinical Oncology (ASCO) Annual Meeting on 29 May 2020, researchers  at Samsung Medical Center in Seoul, Korea, have found useful prognostic information beyond actionable biomarkers when the Guardant360^® test is performed on ALK-rearranged (ALK positive) non-small cell lung cancer (NSCLC) patients. The poster presentation is entitled “Longitudinal monitoring of next generation sequencing (NGS) of plasma cell-free DNA in ALK-rearranged NSCLC patients treated with ALK tyrosine inhibitors.”

Patients with known ALK positive advanced stage NSCLC had blood collected prior to the start of ALK-targeted treatment, 2 months after treatment began, and when the cancer progressed. The main findings of this study showed that the absence of tumour-derived cfDNA prior to and disappearance of cfDNA 2 months after starting ALK-targeted treatment were both independently associated with longer progression-free survival (PFS) and overall survival (OS). The study also found that the co-occurrence of TP53 mutations and ALK alterations in cfDNA prior to treatment was associated with shorter PFS and OS in patients with ALK positive NSCLC.  

Dr. Minsuk Kwon, the first author and recipient of the Conquer Cancer Foundation Merit Award said, “It is absolutely important to identify ALK fusions for appropriate treatment selection. In this study, we also found that the clearance of tumour cfDNA after two months of first line ALK TKI therapy predicted better treatment and survival outcome in ALK positive NSCLC patients.”

Dr. Myung-Ju Ahn, Professor, Department of Hematology and Oncology, Samsung Medical Center and corresponding author of the study said, “Normally, we evaluate cfDNA to identify actionable biomarkers in people with advanced non-small cell lung cancer, which we could do for most patients in this study. But we also found that when we could not detect any tumour DNA in blood prior to treatment there were favourable prognostic implications for patients with ALK positive disease.”

“The Guardant360 assay, which requires only a simple blood draw, allowed these investigators to efficiently assess tumour DNA status before, during, and after treatment with targeted therapy. Their findings show the clinical utility of identifying biomarkers in cfDNA and the favourable prognostic significance of not detecting tumour cfDNA in people living with ALK positive non-small cell lung cancer,” said Dr. Steve Olsen, Chief Medical Officer of Guardant Health Asia, Middle East and Africa (GH AMEA).

The Guardant360 test is increasingly being used to guide treatment in metastatic lung cancer as the number of treatment-relevant genomic alterations continues to grow. Using next-generation sequencing, Guardant360 analyses 74 genes using cell-free tumour DNA from blood samples.   

Poster Presentation Title: Longitudinal monitoring by next generation sequencing of plasma cell-free DNA in ALK-rearranged non-small cell lung cancer (NSCLC) patients treated with ALK tyrosine kinase inhibitors.

Abstract Number: 9603

Poster Number: 369

Authors: Minsuk Kwon, Bo Mi Ku, Sehhoon Park, Hyun Ae Jung, Jong-Mu Sun, Se-Hoon Lee, Jin Seok Ahn, Keunchil Park, Myung-Ju Ahn; Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea; Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea; Sungkyunkwan University School of Medicine, Seoul, South Korea