Immune-related adverse events (irAEs) among urothelial carcinoma (UC) patients treated with PD-1 VS PD-L1 inhibitors: A real-world observational study.

Abstract

e17017 Background: Anti-PD-1/PD-L1 agents are US FDA-approved for patients with advanced or metastatic UC, but limited information exists on real world irAEs among this patient population. We examined the rates and time to onset of select irAEs in UC patients receiving PD-L1s vs PD-1s in the real world. Methods: This observational study included US commercial and Medicare Advantage health plan members from Optum Research Database with UC and treated with a PD-1 or PD-L1 agent between 01-Sep-14 and 30-Apr-19. Baseline characteristics were assessed ≤ 6-months prior to the first claim for anti-PD-1/PD-L1. 21 irAEs were chosen a priori based on the ASCO clinical guideline on irAE management, clinical input, frequency, and cost of treatment. Patients were followed for newly occurring irAEs, based on claims ICD codes, during the PD-1/PD-L1 therapy and up to 180 days after if no new treatment, study period end, death, or disenrollment. Kaplan-Meier method was utilized to calculate time to onset of irAEs. Results: The study included 240 patients receiving PD-L1s and 317 receiving PD-1s. Baseline demographics were similar (Table). The most common irAEs were 1) thyroid disorders, 2) impaired ventricular function with heart failure and vasculitis, 3) rash, and 4) nephritis. UC patients receiving PD-L1s had a lower rate of irAEs vs PD-1s, mainly driven by lower rates of hematologic and endocrine toxicities (Table). UC patients receiving a PD-L1 also had longer time to irAE onset (p-value = 0.05). Conclusions: UC patients receiving PD-L1s had a lower incidence rate of irAEs and longer time to irAE onset than patients on PD-1s. Findings suggest patients receiving PD-1s may require more intense monitoring for irAEs than patients taking PD-L1s. [Table: see text]