C33-30 Worsening Asthma Control After Immune Checkpoint Inhibitor Therapy: Exploring Clinical Predictors

Abstract Rationale Immune checkpoint inhibitors (ICIs) have transformed cancer therapy, but they can provoke immune-related adverse events (irAEs) across organ systems. Previous studies have described a relationship between ICI therapy and reactive airways disease, but data is limited regarding the magnitude of this effect and factors that predispose patients to worsened asthma control. This study aimed to quantify the proportion of patients who experience worsened asthma control after ICI treatment and to identify patient or treatment characteristics associated with this outcome. Methods We conducted a retrospective cohort study of adult cancer patients treated with ICIs between January 2020 and October 2023. Inclusion criteria were a documented diagnosis of asthma prior to ICI initiation and receipt of at least one ICI dose. Patients with COPD and radiographic evidence of emphysema were excluded. Of 663 patients screened, 340 met inclusion criteria. Asthma control was assessed before and after ICI therapy based on changes in asthma medications, frequency of exacerbations requiring systemic corticosteroids, and asthma-related hospitalizations. “Poor asthma control” was defined as an increase in any of these parameters following ICI initiation. Baseline demographic and clinical characteristics were summarized descriptively. Multivariable logistic regression identified factors associated with poor asthma control. All analyses were performed using R (v4.5.0). Results Among 340 included patients, 40 (12%) required escalation in asthma medications, 22 (6.5%) experienced more exacerbations, and 9 (2.7%) had more asthma-related hospitalizations following ICI therapy. None of the following variables— age, sex, race, BMI, smoking status, cancer type, ICI class, pre-treatment spirometry, peripheral eosinophilia, or baseline asthma control—showed statistical differences between patients with and without worsening control. Patients who had worsening asthma control received more doses of ICI on average (9 vs 6, p = 0.002). In multivariable analysis, none of the examined factors (never smoker, PD-1 inhibitor use, non-lung cancer diagnosis, or eosinophil count) were significantly associated with poor asthma control. Conclusions Approximately one in eight patients experienced worsening asthma control after ICI therapy. No consistent demographic or clinical predictors aside from doses of ICI received were identified. These findings suggest that worsening asthma control after ICI treatment may be multifactorial or idiosyncratic rather than linked to specific patient or treatment characteristics, but that there may be a dose-dependent relationship between ICI therapy and worsening asthma control. These findings provide a foundation for future studies to better define mechanisms and identify vulnerable subgroups among patients with pre-existing asthma undergoing ICI therapy. This abstract is funded by: None