Pretreatment Eosinophil Counts in Patients With Advanced or Metastatic Urothelial Carcinoma Treated With Anti-PD-1/PD-L1 Checkpoint Inhibitors

Eosinophils influence antitumor immunity and may predict response to treatment with immune checkpoint inhibitors (ICIs). To examine the association between blood eosinophil counts and outcomes in patients with advanced or metastatic urothelial carcinoma (mUC) treated with ICIs, we identified 2 ICI-treated cohorts: discovery (n=60) and validation (n=111). Chemotherapy cohorts were used as comparators (first-line platinum-based chemotherapy, n=75; second-line or more pemetrexed, n=77). The primary endpoint was overall survival (OS). Secondary endpoints were time on treatment (ToT) and progression-free survival. Univariate and multivariate analyses were performed using Cox proportional hazard models. Associations between changes in eosinophil count at weeks 2/3 and 6 after the start of ICI treatment were analyzed using landmark analyses. Baseline characteristics of the ICI cohorts were similar. In the discovery cohort, an optimal cutoff for pretreatment eosinophil count was determined [Eos-Lo:
Source: Journal of Immunotherapy - Category: Allergy & Immunology Tags: Clinical Studies Source Type: research