A head-to-head study pitting Guardant Health’s lung cancer blood test against standard, tissue-based testing found that the liquid biopsy was able to deliver similar results much faster and with more accuracy—which Guardant says makes the case for its blood-based genomic test to be performed first for all newly diagnosed patients.
The study examined 282 patients with advanced non-small cell lung cancer over nearly two years, with each taking the Guardant360 liquid biopsy aimed at circulating cell-free DNA, as well as the physician’s choice of tissue-based test.
When it came to identifying patients with at least one of seven guideline-recommended predictive genomic biomarkers—EGFR, ALK, ROS1, BRAF, RET, MET and ERBB2, which can also aid in treatment selection—Guardant360 detected alterations in 77 patients, while tissue-based testing found 60; a similar rate, if a little higher.
In addition, for the four mutations targeted by an FDA-approved therapy, namely EGFR, ALK, ROS1 and BRAF, the blood test was able to detect the same alteration in the same patients as traditional biopsy, Guardant said. This can allow patients to be treated first with targeted therapies that may have higher response rates than chemotherapy or immunotherapy.
Total turnaround time for test results was cut down as well, from a median of 15 days to just nine with the blood-based test. The study’s full results are set to be presented at April’s annual meeting of the American Association for Cancer Research in Atlanta.
“Given this assay finds mutations at a similar rate to tissue-based testing, while ensuring patients receive guideline-complete testing with a faster turnaround time, it’s a compelling option to use liquid first ahead of tissue for molecular testing in newly diagnosed advanced NSCLC,” said the study’s senior author, Vassiliki Papadimitrakopoulou, M.D., section chief of thoracic medical oncology at MD Anderson Cancer Center.
Even with tissue genotyping being required by the study, Guardant’s cfDNA analysis rescued 85 patients from a potentially missed genomic diagnosis—including those whose biopsies did not provide enough tumor tissue, as well as those who were incompletely genotyped or found to be negative for the biomarker, according to the study’s AACR abstract.
“This is an important new data set for clinical oncologists that we believe will further accelerate adoption of Guardant360 and, taken together with other recent independent investigations into Guardant360 in this clinical setting, solidifies the case for using blood first for treatment selection,” said Guardant CEO Helmy Eltoukhy, Ph.D.