Pretreatment Lung Function and Checkpoint Inhibitor Pneumonitis in NSCLC

Introduction: Checkpoint inhibitor pneumonitis (CIP) is a serious toxicity of anti-programmed death-(ligand) 1 immunotherapy. Whether pretreatment differences in pul-monary function exist in patients who develop CIP is un-known. We analyzed the pulmonary function tests (PFTs) of patients with NSCLC treated with immune checkpoint in-hibitors (ICIs) to evaluate whether pretreatment lung function was associated with CIP development. Methods: Patients were included if they completed greater than or equal to 1 PFT within 2 years preceding ICI initia-tion. CIP status (CIP+: developed CIP, CIP-: did not develop CIP) was determined clinically. Generalized estimating equation-based linear regression was used to evaluate the effects of time and CIP on lung function. Primary outcomes included the following: percent-predicted forced expiratory volume in 1 second (FEV1pp), percent-predicted forced vital capacity (FVCpp), and FEV1/FVC. Results: A total of 43 patients (34 CIP-, 9 CIP+) with 79 PFTs (59 CIP-, 20 CIP+) were included. CIP+ patients had a 21.7% lower pretreatment FEV1pp compared with the CIP-group (95% confidence interval:-38.6 to-4.7). No statistically significant differences in FVCpp or FEV1/FVC were observed. The prevalence of obstructive lung disease was similar in both groups at 67% and 62% for the CIP+ and CIP-cohorts, as was the prevalence of current/former smoking at 100% and 93%, respectively. Conclusions: Pretherapy differences in lung function were evident between patients who did and did not develop CIP, though the prevalence of obstructive lung disease was similar. Prospective studies are needed to validate these findings, inform potential risk factors for CIP, and investi-gate the effects of ICI treatment and CIP on pulmonary function in patients with NSCLC.(c) 2021 The Authors. Published by Elsevier Inc. on behalf of the International Association for the Study of Lung Cancer. This is an open access article under the CC BY-NC-ND li-cense (http://creativecommons.org/licenses/by-nc-nd/ 4.0/).