Dr. Horn on Monitoring Response and Resistance to Ensartinib in ALK+ NSCLC
Leora Horn, MD, MSc, associate professor of cancer research, Vanderbilt University Medical Center, discusses the use of circulating tumor DNA analysis as a means to monitor response to, as well as resistance to, ensartinib in patients with ALK–positive non–small cell lung cancer.
Leora Horn, MD, MSc, associate professor of cancer research, Vanderbilt University Medical Center, discusses the use of circulating tumor DNA analysis as a means to monitor response to, as well as resistance to, ensartinib in patients with ALK—positive non–small cell lung cancer.
The study involved a cohort of patients from the phase II eXalt2 study (NCT01625234) of ensartinib. In 76 enrolled patients, all determined to have ALK-positive disease by fluorescence in situ hybridization, Horn and her colleagues assessed DNA from plasma samples for commonly occurring mutations using a panel of probes developed in collaboration with Resolution Biosciences. A total of 56 patients had genomic alterations detected by next-generation sequencing (NGS), and of those, 80% had ALK rearrangements.
Importantly, 5 patients with ALK-positive disease in their tissue samples did not show ALK positivity via NGS, which suggests that NGS may miss some patients who have ALK-positive disease, given that 4 of those patients responded to ensartinib. Furthermore, different responses to ensartinib were noted by variant; patients with variant 1 had better response and progression-free survival to ensartinib than did patients with variant 3.
