A Randomized Trial of Combined PD-L1 and CTLA-4 Inhibition with Targeted Low-Dose or Hypofractionated Radiation for Patients with Metastatic Colorectal Cancer
Purpose:Prospective human data are lacking regarding safety, efficacy and immunologic impacts of different radiation doses administered with combined PD-L1/CTLA-4 blockade.Experimental Design:We performed a multicenter phase 2 study randomizing subjects with metastatic microsatellite-stable colorectal cancer (CRC) to repeated low-dose fractionated RT (LDFRT) or hypofractionated radiation (HFRT) with PD-L1/CTLA-4 inhibition. The primary endpoint was response outside the radiation field.