(SLB-018) Immune-related Adverse Events (irAEs) associated with Immune Checkpoint Inhibitor (ICI) Therapy in Bladder Cancer: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Monday, August 25, 2025

11:45 AM - 12:45 PM ET

Presenting Author(s)

PG

Pooja Gokhale

University of Georgia College of Pharmacy, United States

Co-Author(s)

LV

Lorenzo Villa Zapata, PharmD, PhD

Clinical and Administrative Pharmacy, College of Pharmacy, University of Georgia, Athens, Georgia, USA, Georgia, United States

Background: Immune-related adverse events (irAEs) such as hyperthyroidism, hypothyroidism, pruritis, and rash are commonly associated with immune checkpoint inhibitor (ICI) therapy. ICIs are recommended at various stages of bladder cancer treatment, and appropriate management of irAEs is crucial for improving long-term outcomes in bladder cancer.

Objectives: To conduct a systematic review and meta-analysis of randomized controlled trials to assess the incidence of immune-related adverse events associated with immune checkpoint inhibitor therapy in bladder cancer.

Methods: A comprehensive literature search was conducted across PubMed/MEDLINE, Embase, Web of Science, Cochrane Library, and Epistemonikos from inception until January 2025. Additional sources, including references of the included studies, clinicaltrials.gov, annual meeting abstracts from ASCO and ESMO, and the WHO International Clinical Trials Registry Platform, were also reviewed for relevant studies. Phase II or III randomized controlled trials in which one of the experimental arms consisted of atezolizumab, pembrolizumab, nivolumab, or avelumab monotherapy were included. A random-effects model was employed to conduct the meta-analysis using R Statistical Software, version 4.3.3.

Results: Out of the initial 1095 articles screened, 9 were included in the systematic review and meta-analysis. The risk ratio (RR) of hypothyroidism in the ICI arm was 5.87 (95% CI: 3.23, 10.67) compared with the comparator arm. For hyperthyroidism, the RR was 11.05 (95% CI: 4.20, 29.03). For pruritus and rash, the risk ratios were 4.95 (95% CI: 2.82, 8.70) and 2.92 (95% CI: 1.51, 5.64), respectively.

Conclusions: Bladder cancer patients treated with immune checkpoint inhibitors are at significant risk of immune-related adverse events. These events range from mild to severe, necessitating appropriate management strategies to enhance the quality of life for affected patients.