Prognostic variables associated with improved outcomes in patients with stage III NSCLC treated with chemoradiation followed by consolidation Pembrolizumab: a subset analysis of a phase II study from the Hoosier Cancer Research Network LUN 14-179

Abstract

Introduction HCRN LUN 14-179 is a phase II trial of consolidation pembrolizumab following concurrent chemoradiation for the treatment of patients with stage III NSCLC. Time to metastatic disease, progression free survival and overall survival appear superior to historical controls of chemoradiation alone. Unfortunately, not all patients benefit from consolidation immunotherapy. We performed a univariate analysis evaluating variables associated with PFS, metastatic disease, and OS.

Methods We conducted a retrospective analysis from patients enrolled on HCRN LUN14-179. Data collected included age, sex, stage, smoking status, PD-L1 status, >G2 vs <G1 adverse event, <G2 vs. >G3 pneumonitis, duration of pembrolizumab (<4 vs. >4 cycles), chemotherapy regimen, PS 0 vs 1, time to start pembrolizumab (4-6 vs. 6-8 weeks from radiation), V20 (<20% vs. >20%). Univariable Cox regression was performed to determine the variables associated with 3 endpoints: TMDD; PFS; and OS.

Results From April 2015 to December 2016, 93 patients were enrolled and 92 were included in the efficacy analysis (1 patient was ineligible). For TMDD, improved outcomes may be associated (p<0.1) with stage IIIA, non-squamous cell, >4 cycles of pembrolizumab, and V20< 20%. For PFS, improved outcomes (p<0.1) may be seen for >4 cycles of pembrolizumab, and V20< 20%. For OS, improved outcomes (p<0.1) may be seen for non-squamous histology, >4 cycles of pembrolizumab.

Conclusion Non-squamous NSCLC, longer duration of pembrolizumab, and V20< 20% may be associated with prolonged time to metastatic disease or death, PFS, and OS for patients with stage III NSCLC treated with chemoradiation followed by pembrolizumab.