3417 - Interstitial lung disease associated with immune-checkpoint inhibitors in malignant diseases

Background

Immune-checkpoint inhibitors (ICI) have recently been used in many types of cancers including non-small cell lung cancer (NSCLC). Interstitial lung disease associated with ICI (ICI-ILD) is a serious immune-related adverse event. However, comprehensive clinical characterization of ICI-ILD is still lacking.

Methods

We retrospectively analyzed clinical and imaging data of all consecutive ICI treated patients in Kurashiki Central Hospital (Okayama, Japan) between January 2016 and March 2019. We elucidated clinical characteristics, radiopathological patterns, therapeutic strategies and outcomes of ICI-ILD and analyzed the prognostic factor of ICI-ILD.

Results

Among 316 (222 NSCLC and 94 non-NSCLC) treated with ICI, 35 (11.1%) were diagnosed as ICI-ILD. Of those, NSCLC/gastric cancer/urinary cancer/head and neck cancer/malignant lymphoma were 26/2/2/4/1, respectively: mean age was 69.3 ± 9.0 years; 29 (82.9%) were men; 19 (54.3%) received Nivolumab monotherapy and 10 (28.6%) received Pembrolizumab monotherapy; Best objective response rate until ICI-ILD diagnosis was 48.6% (11/35); The median time (range) from ICI introduction to ICI-ILD was 57 (22-155) days. CTCAE grade 1/2/3 + 4/5 was 10 (28.6%)/14 (40.0%)/7 (20.0%)/4 (11.4%), respectively; Organizing pneumonia was found in 57.1% (20/35) in CT and 66.7% (4/6) in transbronchial lung biopsy; Lymphocyte differential count of bronchoalveolar lavage fluid (range) was 41 (33-60) %; 26 (74.3%) were treated with corticosteroid; 29 (82.9%) had ICI-ILD improved but 6 (17.1%) did not. The median survival time was significantly different between ILD improved group and non-improved group (17.1 months vs 0.8 months, p < 0.001). Multivariate Cox regression analysis demonstrated that only ICI-ILD improvement is a significant prognostic factor (HR: 0.03; 95% CI, 0.003-0.305; p = 0.003).

Conclusions

In our real-world experience, half of ICI-ILD patients had a response toward malignancy. Organizing pneumonia was the most common radiopathological pattern and lymphocyte differential count of bronchoalveolar lavage fluid was elevated in ICI-ILD. If ICI-ILD does not improve, its prognosis may be very poor.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.