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.