Phase II Trial of Concurrent Atezolizumab With Chemoradiation for Unresectable NSCLC

Consolidation durvalumab after chemoradiation (CRT) is the current standard of care for locally advanced NSCLC. We hypothesized that adding immunotherapy concurrently with CRT (cCRT) would increase efficacy without additive toxicity.

This phase II study was conducted in two parts. Part 1 (n = 10) involved administration of conventionally fractionated CRT followed by consolidation chemotherapy (atezolizumab [two cycles] and maintenance atezolizumab up to 1 y). Part 2 (n = 30) involved administration of cCRT with atezolizumab followed by the same consolidation and maintenance therapies as in part 1. Programmed cell death ligand-1 staining cutoffs (1% or 50%) using Dako 22C3 immunohistochemistry were correlated with clinical outcomes.

The overall toxicities for part 1/2 were overall adverse events of grade 3 and above of 80%/80%; immune-related adverse events of grade 3 and above of 30%/20%; and pneumonitis of grade 2 and above of 10%/16%, respectively. In part 1, for preliminary efficacy results, with a median follow-up of 22.5 months, the median progression-free survival was 18.6 months, and the overall survival was 22.8 months. In part 2, with a median follow-up time of 15.1 months, the median progression-free survival was 13.2 months, and the overall survival was not reached. There was no difference in cancer recurrence regardless of programmed cell death ligand-1 status.

Atezolizumab with cCRT is safe and feasible and has no added toxicities compared with historical rates.