Remaining questions, next steps
Dr. Greenberg said one of the study’s limitations is that the investigators did not characterize the TIL product.
“Studies have predicted that there’s a particular type of cell, a stem-like T cell, that’s responsible for mediating the efficacy,” he commented. He referred to research from Steven Rosenberg, MD, PhD, and colleagues at the National Cancer Institute, where TILs were first used in 2002.
Dr. Greenberg also raised the question of whether high-dose IL-2 was required post infusion, given that the patients were lymphodepleted before receiving lifileucel.
Future steps for TIL therapy, he said, should include identification of biomarkers for success or failure; strategies to enhance generation and expansion of tumor-reactive T cells; postinfusion strategies, such as using vaccines and/or checkpoint inhibitors to increase therapeutic activity; genetic modifications to enhance the function of TILs in the tumor microenvironment; and research into other tumor types that may be effectively treated with TILs.
The study was supported by Iovance Biotherapeutics. Dr. Chesney has received research funding from Iovance and other companies and has consulted for Amgen and Replimune. Dr. Greenberg has served on scientific advisory boards, has received grant/research support, and owns stock in several companies that do not include Iovance.
A version of this article first appeared on Medscape.com.