Efficacy and safety of nivolumab in non‐small cell lung cancer with preexisting interstitial lung disease

BACKGROUND: The risk of developing lung cancer is high in patients with interstitial lung disease (ILD), as few treatment options are available. Immune checkpoint inhibitors (ICI) are used for the treatment of non‐small cell lung cancer (NSCLC) in clinical practice; however, in patients with preexisting ILD, the risk of ICI‐related pneumonitis is unknown. We evaluated the efficacy and lung toxicity of nivolumab in patients with NSCLC and ILD. METHODS: We retrospectively reviewed the medical records of 216 NSCLC patients who had received nivolumab therapy. The existence of ILD in these patients was determined by lung computed tomography findings; 26 patients had ILD. We evaluated the efficacy of nivolumab by measuring the response rate (RR), progression‐free survival (PFS) duration, and lung toxicity by incidence, severity, and outcome of nivolumab‐related ILD. RESULTS: The RR and median PFS of the ILD and non‐ILD groups were 27% versus 13% (P = 0.078) and 2.7 (95% confidence interval [CI], 1.7–5.3) versus 2.9 months (95% CI 2.1–3.4; P = 0.919), respectively. The incidences of total and severe nivolumab‐related pneumonitis were significantly higher in the ILD group than in the non‐ILD group (31% vs. 12%, P = 0.014 and 19% vs. 5%, P = 0.022, respectively). No death from nivolumab‐related pneumonitis occurred. Over 50% of the patients in both groups with nivolumab‐related pneumonitis showed improvement over time. CONCLUSION: Relative to the non‐ILD group, nivolumab‐related pneumonitis was observed more frequently in the ILD group; however, most cases were manageable.