“This is a large, well-done study,” said Ravindra Uppaluri, MD, PhD, Chief of the Division of Otolaryngology in the Department of Surgery at the Brigham and Women’s Hospital and Director of Head and Neck Surgical Oncology at Dana-Farber Cancer Institute, who underscored the small number of dose-limiting toxicities and encouraging overall response rate. Given recent research, he added, linking stereotactic body radiotherapy (SBRT) to immune checkpoint inhibition “makes a lot of sense.”
“A review from Formenti and Demaria has shown how SBRT can induce innate immune response compared with standard fractionation…,1 which drives adaptive response and may lead to the holy grail of abscopal effect, where nontargeted lesions develop a reduction because of this adaptive response,” revealed Dr. Uppaluri.
‘Exciting Area of Research’
Although impressed by the limited number of dose-limited toxicities and superior control of irradiated lesions, Dr. Uppaluri stressed the need to separate the effects of pembrolizumab from SBRT alone. He also cited research demonstrating that higher levels of radiation can lead to decreased type 1 interferon response. Based on these data, he said, investigators could potentially use a slightly lower dose for more beneficial effects.
“Combining SBRT with immunotherapies is a very exciting area of research. There’s clearly a lot of potential here,” Dr. Uppaluri concluded. ■
DISCLOSURE: Dr. Uppaluri has served as a consultant for and received research funding from Merck.
1. Vanpouille-Box C, Formenti SC, Demaria S, et al: Toward precision radiotherapy for use with immune checkpoint blockers. Clin Cancer Res 24:259-265, 2018.
Results from the first and largest prospective trial to determine the safety of multisite ablative stereotactic body radiotherapy (SBRT) in combination with anti–programmed cell death protein 1 (anti–PD-1) immunotherapy pembrolizumab (Keytruda) suggest the combination regimen may improve outcomes...