Op0334 Outcomes in Patients With Pre-Existing Autoimmune Disease on Immune Checkpoint Inhibitor Therapy for Treatment of Cancer

Background: There is growing awareness that immunotherapy-related adverse events (iRAE) from immune checkpoint inhibitor (ICI) therapy are being correlated with treatment outcomes of various cancers. Patients with pre-existing autoimmune disease (AID) have been excluded from ICI clinical trials. It is important to understand whether patients with pre-existing AID respond differently to ICI therapy and thereby have a different mortality risk or increased risk of iRAE compared to patients without AID. Several recent studies suggest equivalent survival rates in patients with AID [1,2,3], though the largest study by Tang et al. was limited by short follow-up duration. Objectives: To assess mortality risk in a national cohort of patients with pre-existing AID being treated with ICI therapy. Methods: We conducted a cohort study using the TriNetX Diamond network, a large, multi-center network of U.S. electronic health records. International Classification of Diseases, Tenth Revision (ICD-10) codes were used to identify patients with pre-existing AID on anti-programmed death-1/programmed death ligand-1 (PD-1/PD-L1) immunotherapy for the most common malignancies treated with ICI therapy (C34: bronchus and lung, C15-26: digestive organs, C43: melanoma, and C64-68: urinary tract). We analyzed rates of mortality following ICI initiation. Propensity score matching included factors to adjust for demographics and co-morbidities. Kaplan-Meier analysis and Cox proportional hazards models were used to estimate the probability of the outcome of interest. Results: A total of 25,153 patients on ICIs with known AID and 78,547 patients without known AID were included. After 1:1 propensity score matching utilizing the same limited covariates as the Tang et al. study (sex, race, age, malignancy type), 25,148 patients in each group were compared; HR for mortality for patients with known AID compared to those without AID was 1.039 (95% CI 1.01-1.07). A subsequent analysis was performed with 1:1 propensity score matching with additional adjustment for co-morbidities and medications, resulting in 2 cohorts of 23,714 patients (Table 1). No significant mortality difference was observed between these groups with observed HR 0.97 (95% CI 0.94-1.00) with Kaplan-Meier survival curve depicted in Figure 1. Conclusion: This study of a large population of patients receiving ICI therapy provides further evidence that there is no significant difference in mortality risk in patients with pre-existing AID compared to those without. REFERENCES: [1] Han CY, et al. Association Between Toxic Effects and Survival in Patients with Cancer and Autoimmune Disease Treated with Checkpoint Inhibitor Immunotherapy. JAMA Oncol. 2022;8(9):1352-1354. [2] Tang K, et al. Pre-Existing Autoimmune Disease and Mortality in Patients Treated with Anti-PD-1 and Anti-PD-L1 Therapy. J Natl Cancer Inst. 2022 Aug 8;114(8):1200-1202. [3] McCarter KR, et al. Mortality and immune-related adverse events after immune checkpoint inhibitor initiation for cancer among patients with pre-existing rheumatoid arthritis: a retrospective, comparative, cohort study. The Lancet Rheumatology. 2023;5(5):e274-e283. [4] Lee C, et al. Pre-Existing Autoimmune Disease Increases the Risk of Cardiovascular and Noncardiovascular Events After Immunotherapy. J Am Coll Cardiol CardioOnc. 2022;4(5):660-669. Acknowledgements: NIL. Disclosure of Interests: Gregory Challener: None declared, Kevin Sheng-Kai Ma: None declared, Minna J. Kohler: None declared, Chio Yokose: None declared, Hyon Choi ANI, LG, Horizon, Shanton, Protalix, Horizon.