Dr. Polsky on Using ctDNA as a Biomarker for Melanoma

David Polsky, MD, PhD, professor of dermatologic oncology, Ronald O. Perelman Department of Dermatology, NYU Langone’s Perlmutter Cancer Center, discusses using circulating tumor DNA (ctDNA) kinetics as a biomarker to predict survival and monitor disease activity in patients with unresectable or metastatic melanoma.

Polsky and researchers studied patients who are part of the randomized phase III COMBI-d trial, which evaluated dabrafenib (Tafinlar) versus dabrafenib plus trametinib (Mekinist) in patients with unresectable or metastatic melanoma. In this analysis, researchers examined the ctDNA enrolled 345 patients at the baseline.

Polsky and researchers measured BRAF V600E/K ctDNA at baseline and week 4 in plasma samples. Mutation-specific droplet digital PCR assays were used to measure, according to Polsky. The ctDNA results were categorized as positive/negative using an analytically validated detection threshold of 0.25 copies/mL. The primary goals of the study were to examine progression-free survival and overall survival.