Guardant Health said its Guardant360 test enabled South Korean investigators to independently associate both the absence of tumor-derived cell-free DNA (cfDNA) before starting ALK-targeted treatment, and the disappearance of cfDNA two months after, with longer progression-free survival (PFS) and overall survival (OS).
The researchers, based at Samsung Medical Center in Seoul, also found useful prognostic information beyond actionable biomarkers when they performed the Guardant360 test on ALK-rearranged (ALK positive) non-small cell lung cancer (NSCLC) patients.
Patients with known ALK positive advanced stage NSCLC had blood collected prior to the start of ALK-targeted treatment, two months after treatment began, and when the cancer progressed.
The findings were intended to show the clinical utility of identifying biomarkers in cfDNA and the favorable prognostic significance of not detecting tumor cfDNA in people living with ALK positive non-small cell lung cancer. “”The Guardant360 assay, which requires only a simple blood draw, allowed these investigators to efficiently assess tumor DNA status before, during, and after treatment with targeted therapy,” Steve Olsen, M.D., Ph.D., CMO Medical Officer of Guardant Health Asia, Middle East and Africa (GH AMEA), said in a statement.
The researchers detailed their findings in a poster presentation of their study, titled “Longitudinal monitoring of next generation sequencing (NGS) of plasma cell-free DNA in ALK-rearranged NSCLC patients treated with ALK tyrosine inhibitors.” The poster was presented Friday during the 2020 American Society of Clinical Oncology (ASCO) Annual Meeting.
“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 tumor DNA in blood prior to treatment there were favorable prognostic implications for patients with ALK positive disease,” stated Myung-Ju Ahn, MD, the study’s corresponding author, and Professor, Department of Hematology and Oncology, at Samsung Medical Center.
Added Minsuk Kwon, MD, PhD, the first author and recipient of the Conquer Cancer Foundation Merit Award, said in a statement: “It is absolutely important to identify ALK fusions for appropriate treatment selection.”
“In this study, we also found that the clearance of tumor cfDNA after two months of first line ALK TKI therapy predicted better treatment and survival outcome in ALK positive NSCLC patients,” Kwon said.