Real-World Evaluation of Factors for Interstitial Lung Disease Incidence and Radiologic Characteristics in Patients With EGFR T790M-positive NSCLC Treated With Osimertinib in Japan.

INTRODUCTION: Using real-world Japanese postmarketing data, we characterized interstitial lung disease (ILD) development during the second- or later-line osimertinib treatment for EGFR mutation-positive NSCLC. Retrospective radiologic image evaluation of patients developing ILD was also performed.
METHODS: Patients who had ILD events reported as an adverse drug reaction by their physicians and who were assessed as having developed ILD as assessed by an ILD expert committee in Japan were included.
RESULTS: Among 3578 patients, 252 ILD events were reported in 245 patients (6.8%) by their attending physicians. The median (range) time to the first onset of ILD after osimertinib treatment initiation was 63.0 (5-410) days, and 29 patients with a fatal outcome were reported. The ILD expert committee assessed 231 of 3578 patients (6.5%) as having ILD. A previous history of nivolumab therapy (adjusted OR: 2.84; 95% confidence interval: 1.98-4.07) and a history or concurrence of ILD (3.51; 2.10-5.87) were identified as factors potentially associated with ILD onset during osimertinib treatment. In patients who had received a previous nivolumab treatment, the number and proportion of patients developing ILD were highest for patients who discontinued nivolumab treatment within the first month before initiating osimertinib; trends for decreasing incidence and proportion were observed, with an increasing duration between the end of nivolumab treatment and the initiation of osimertinib treatment.
CONCLUSIONS: The frequency of ILD was consistent with the known osimertinib safety profile in the Japanese population. A history or concurrence of ILD and history of previous nivolumab therapy are factors potentially associated with ILD onset during osimertinib treatment.