Potential risk factors of pneumonitis associated with consolidation pembrolizumab after chemoradiation in unresectable NSCLC patients.

167Background: We have previously shown that consolidation pembrolizumab after chemoradiation is safe in a 93 patient-clinical trial of unresectable stage III NSCLC patients (Durm, ASCO 2016). However 15 patients (16%) developed grade ≥2 pneumonitis. There is limited data on risk factors for developing pneumonitis in this population. We conducted a retrospective review of these patients to identify potential clinical, biologic, radiographic and radiation treatment related risk factors for developing pneumonitis. Methods: We evaluated ECOG PS, age, gender, smoking status, stage, histology, chemo regimen, consolidation chemotherapy, TILs, PDL-1 status, PFTs, PET SUVs, grade of pre-existing ILD, COPD and Radiation dosimetry plans. Logistic regression and fisher’s-exact test were used for the odds ratio and p-values. Results: See Table. [1] [1] Age, histology, stage, chemo, PFTs, SUVs and PDL1 were not significant [2] n = sample size p = pneumonitis [3] Moderate/severe COPD was not seen in any patients with p...