Phase II trial of concurrent atezolizumab with chemoradiation in unresectable non-small cell lung cancer.

Abstract

INTRODUCTION\nConsolidation durvalumab after chemoradiation (CRT) is the current standard of care in locally advanced non-small cell lung cancer. We hypothesized that adding immunotherapy concurrently with CRT (cCRT) increased efficacy without significant additive toxicity.\n\n\nMETHODS\nThis phase II study was conducted in two parts. Part 1 (N=10) administered conventionally fractionated CRT followed by consolidation chemotherapy-atezolizumab x 2 cycles and maintenance atezolizumab up to 1 year. Part 2 (N=30) administered cCRT with atezolizumab followed by the same consolidation and maintenance therapy as in Part 1. PD-L1 staining cutoffs (1% or 50%) using Dako 22c3 immunohistochemistry were correlated to clinical outcomes.\n\n\nRESULTS\nThe overall toxicities for Parts 1/2 are: overall AE grade ≥ 3: 80%/80%; immune-related AEs ≥ grade 3: 30%/20%; pneumonitis ≥ grade 2: 10%/16%. For preliminary efficacy results, in Part 1, with a median follow up of 22.5 months (mos) the median PFS is 18.6 mos and OS is 22.8 mos . In Part 2, with a median follow up time of 15.1 mos, the median PFS is 13.2 mos and OS is not reached. There was no significant difference in cancer recurrence regardless of PD-L1 status.\n\n\nCONCLUSION\nAtezolizumab with cCRT is safe and feasible and has no added toxicities over historical rates.