Dr. Gubens on Prevalence of EGFR/ALK/ROS1 and PD-L1 Expression in NSCLC

Matthew Gubens, MD, an assistant professor of thoracic oncology at the University of California San Francisco, discusses the prevalence of patients with non—small cell lung cancer (NSCLC) who harbor mutations in EGFR/ALK/ROS1 as well as PD-L1 expression.

This poses an interesting question, Gubens explains. With respect to the KEYNOTE-024 study, the results demonstrated that physicians can administer pembrolizumab (Keytruda) if their patients' PD-L1 levels are 50% or higher. This specifically excludes EGFR and ALK; however, by looking at the NCCN guidelines, it is important to know that if a patient has both an EGFR mutation and PD-L1 at high levels, the disease should be treated first with an EGFR-targeted agent.

It is unknown how often those correlate, he adds. In Gubens' clinical practice, he has a few such patients, but phase III data show that EGFR-positive patients often underperform other patients because they tend to be less-inflamed tumors.

Again, Gubens advises that in such situations, the EGFR mutation should be treated first because that is the targetable lesion associated with the higher response rate. Patients will get the immunotherapy eventually, but the response rates are higher and the durations are higher with the TKI.