As for overall survival, 72% of patients with tumors that contained high levels of PD-L1 were alive at 6 months, compared with 53% of those whose tumors contained low levels of PD-L1. This difference trended toward statistical significance (HR, 0.65; P = .134) and may also change as data from additional patients are realized, she said.
Dr. Gandhi noted that data from two ongoing studies will be used to "further explore the relationship between tumor PD-L1 expression and MK-3475 activity in NSCLC patients."
In an interview, Dr. Patricia M. LoRusso, director of the Center for Translational Therapeutics at Wayne State University’s Karmanos Cancer Institute, Detroit, characterized the MK-3475 biomarker as "maturing, but I still think it’s under investigation. I still think we have a ways to go in identifying the best predictive biomarker. I don’t think it’s 100% foolproof by any means."
Both studies were funded by Merck. Dr. Daud disclosed that he has served on the advisory board of Merck and GlaxoSmithKline. Dr. Gandhi said that she had no relevant financial conflicts to disclose.
Dr. LoRusso disclosed that she has received research funding from Agios Pharmaceuticals.