Association Between the Occurrence and Spectrum of Immune-Related Adverse Events and Efficacy of Pembrolizumab in Asian Patients With Advanced Urothelial Cancer: Multicenter Retrospective Analyses and Systematic Literature Review

Abstract

An association between the development of overall or specific immune-related adverse events (irAEs) and outcomes of immune checkpoint inhibitors has recently been suggested. To address this emerging association in patients with urothelial cancer receiving pembrolizumab, we conducted a multicenter retrospective analysis, which is the first and largest in an Asian cohort as well as a systematic literature review. We retrospectively evaluated 97 patients with advanced urothelial cancer treated with pembrolizumab as second- or later-line treatment between January 2018 and March 2019. irAEs were categorized by the involved organs and graded using Common Terminology Criteria for Adverse Events version 5.0. Associations between irAEs and pembrolizumab efficacy, including objective response rate (ORR), progression-free survival (PFS), and overall survival (OS), were evaluated. In our review of the literature, 28 studies, including 9 studies involving patients with urothelial cancer and 19 studies reporting the association between outcomes and spectrum of irAEs, were analyzed. Patients with irAEs had significantly higher ORR (52% vs. 16%, P < .01), longer PFS (11.0 months vs. 3.6 months, P < .01) and OS (median not reached vs. 13.1 months, P = .12) than in patients without irAEs. Endocrine (P = .02), pneumological (P = .06), and other (gastrointestinal, hematological, hepatic) (P = .04) irAEs were associated with increased ORR, whereas skin irAEs were not. Endocrine irAEs (P = .04) was associated with improved OS, whereas pneumological and skin irAEs were not. The association between the occurrence of irAEs and clinical efficacy of immune checkpoint inhibitors was consistently supported by the multiple studies we reviewed. The association between clinical outcomes and the spectrum of organs/systems affected by irAEs seems to be inconsistent and could be dependent on tumor type. irAEs were associated with a higher ORR and better survival of patients with advanced urothelial cancer treated with pembrolizumab.

Keywords: Immuno-oncology drug; Overall survival; Prognostic factor; Progression-free survival; System/organ involved.