Posted: Friday, November 18, 2022
Caroline Weipert, MS, of Guardant Health, Redwood City, California, presented data on behalf of her colleagues at the 2022 Society for Immunotherapy of Cancer (SITC) Annual Meeting (Abstract 6) on the use of circulating cell-free tumor DNA (ctDNA) to predict therapeutic outcomes in non–small cell lung cancer (NSCLC). Further study of the utility of ctDNA molecular response in “an adaptive clinical trial design to evaluate the impact of early treatment interventions on patient outcome is ongoing,” they reported.
Ms. Weipert and colleagues retrospectively evaluated Guardant360 Response algorithm data for 282 patients with NSCLC who had received treatment with EGFR tyrosine kinase inhibitors or immune checkpoint inhibitors. The patients included had received a ctDNA test within 15 weeks prior to treatment and a second test 3 to 15 weeks after treatment.
Of the patients receiving either EGFR tyrosine kinase inhibitors or immune checkpoint inhibitors, 34% were classified as molecular responders (achieving a > 50% decrease in mean variant allele fraction ratio from pretreatment to treatment), 47% were nonresponders, and 19% were not evaluable by the Guardant360 algorithm.
Molecular responders had significantly longer times to the next treatment on EGFR tyrosine kinase inhibitors and immune checkpoint inhibitors compared with nonresponders receiving the same therapy (P < .005). Time to treatment discontinuation was also significantly longer for molecular responders than nonresponders in the cohort that received EGFR tyrosine kinase inhibitors (P < .005).
Disclosure: Ms. Weipert and colleagues are employees of Guardant Health.