Safety and Clinical Outcomes of Immune Checkpoint Inhibitors in Patients With Cancer and Preexisting Autoimmune Diseases

Immunotherapy has revolutionized treatment outcomes in numerous cancers. However, clinical trials have largely excluded patients with autoimmune diseases (ADs) due to the risk of AD flares or predilection for developing organ-specific inflammation. The objective of this study was to evaluate the safety and efficacy of immunotherapy in patients with cancer and preexisting ADs. A retrospective, single-center study of patients with cancer initiated on immune checkpoint inhibitors between 2012 and 2019 was conducted. The primary outcome was the development of immune-related adverse events (irAEs) with respect to the presence of AD at baseline. Associations were assessed using Kaplan-Meier curves, bivariate and multivariable analyses. Of the 417 patients included in this study, 63 patients (15%) had preexisting ADs. A total of 218 patients (53%) developed at least 1 irAE. There was no association between the presence of baseline AD on the development, grade, or number of irAEs; time to irAE or irAE recovery; systemic corticosteroid or additional immunosuppressant treatment for irAEs; permanent treatment discontinuation; or overall response rate. Two smaller cohorts were studied, melanoma and non-small cell lung cancer, and there was no effect of baseline AD on overall survival on either cohort. However, a greater proportion of patients with baseline ADs had full recovery from their irAE (P=0.037). Furthermore, age below 65, baseline steroid use, and single-agent immunotherapy regimens were protective in terms of the development of irAEs. Our study suggests that immune checkpoint inhibitors have similar safety and efficacy profiles in patients with preexisting ADs.