Effect of pre-treatment of EGFR-TKIs on immune checkpoint inhibitor- associated interstitial lung disease in lung cancer patients: Analysis using a Japanese claims database

Background: Immune checkpoint inhibitors (ICI) and epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) are key drugs for the treatment of EGFR mutation-positive lung cancer. While previous studies reported that the concomitant use of these drugs increases the risk of interstitial lung disease (ILD), the impact of sequential treatment on ILD risk is unknown. This study aimed to analyze the impact of EGFR-TKI pre-treatment on the risk of developing ILD after subsequent ICI administration. Materials and methods: We conducted a retrospective study using a Japanese health insurance claims database. ILD-naive lung cancer patients who had first ICI administration during the screening period from July 2014 to February 2019 were selected. Patients who had ILD within 1 year of receiving the first ICI dose were included in the ILD group. Multivariate logistic regression analysis was conducted to evaluate the effect of pre-treatment with EGFR-TKI on the development of ICI-associated ILD. Results: A total of 353 patients were included, of which 61 were included in the ILD group. The median time to onset of ILD after ICI administration was 3 months. Multivariate logistic regression analysis revealed that pre-treatment with EGFR-TKI was not associated with ICI-associated ILD (odds ratio: 0.26, 95% confidence interval: 0.033 - 2.01). Conclusion: Although further analyses are required to confirm our findings, this study indicated that pre-treatment with EGFRTKI might not increase the ILD risk after ICI treatment.