Clinical characteristics and pharmacovigilance signals of immune checkpoint inhibitor-associated cystitis and ureteritis: analysis of FAERS reports and published cases
Year: 2026
Type: article
Abstract: Background: Immune checkpoint inhibitor (ICI)-associated cystitis and ureteritis are uncommon urinary immune-related adverse events that are difficult to distinguish from infection or other urinary tract complications. Their clinical phenotype and pharmacovigilance signal remain incompletely defined. Methods: We combined a pooled analysis of published cases with a FAERS disproportionality analysis from 2004Q1 to 2026Q1. Published cases were reviewed for clinical presentation, treatment, rechallenge, and time-to-onset. FAERS reports were deduplicated at the CASEID level. A broad cystitis-inclusive definition included IMMUNE-MEDIATED CYSTITIS, CYSTITIS NONINFECTIVE, URETERITIS, and CYSTITIS; a high-specificity definition excluded the nonspecific Preferred Term CYSTITIS. Disproportionality was assessed using reporting odds ratios (RORs), proportional reporting ratios, chi-square statistics, and information components. Results: Twenty-eight reports comprising 45 unique patients were included. The median age was 56 years, and lung cancer was the most common malignancy. Published cases commonly showed urinary frequency, dysuria, hematuria, leukocyturia, inflammatory imaging or cystoscopic abnormalities, and corticosteroid responsiveness. Upper urinary tract involvement was documented in 13 of 33 patients with available CT data. Median time-to-onset was 62 days among 24 evaluable cases, and recurrence occurred in 5 of 9 rechallenged patients. In FAERS, 20,257,224 deduplicated CASEIDs were analyzed. The broad cystitis-inclusive definition identified 397 ICI-associated cases and showed only a weak signal (ROR, 1.12; 95% CI, 1.02-1.24), whereas the high-specificity definition identified 151 cases and yielded a stronger signal (ROR, 9.04; 95% CI, 7.63-10.70). Class-level signals were also observed, and the overall high-specificity signal remained positive across sensitivity analyses. Conclusion: These findings support ICI-associated cystitis and ureteritis as an uncommon urothelial inflammatory irAE spectrum. Phenotype-aware outcome definition is important in pharmacovigilance because nonspecific cystitis coding may dilute the reporting signal.
Source: Frontiers in Pharmacology
Authors: Yuanyuan Zhang, Jiajin Yang
Institution: Yichun University
Language: English
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W7222680185