The Eosinophil Changes, Efficacy and Safety of Pembrolizumab in Advanced Urothelial Carcinoma Patients with an Older Age and a Poor Performance Status.

Abstract

To evaluate the eosinophil changes, efficacy and safety of pembrolizumab treatment in advanced urothelial carcinoma patients of older age and those with a poor performance status (PS). Consecutive patients with advanced UC who received pembrolizumab after the failure of platinum-based chemotherapy between January 2018 and June 2021 were retrospectively examined. 105 patients (median age, 72 years), 71.4% of whom were men, were enrolled. Patients of ≥75 years of age were considered to be older patients (n=40), and patients with PS ≥2 were considered to have a poor PS (n=10). The objective response and disease control rates were 42.5% and 52.5%, respectively, in older patients and 0% and 10.0%, respectively, in patients with a poor PS. Overall survival (OS) in the older and younger groups did not differ to a statistically significant extent. However, a poor PS was significantly associated with poor survival. Safety analyses demonstrated no significant difference in the occurrence of any immune-related adverse events (irAEs), including grade ≥3, between the older and younger groups. However, a poor PS was significantly associated with the low occurrence of any irAEs. The change of the eosinophil count, the increase of the relative eosinophil count (REC) and the decrease of the neutrophil-to-eosinophil ratio (NER) did not differ to a statistically significant extent between the older and younger groups, but showed significant differences between the poor and good PS (PS 0-1) groups. Pembrolizumab for advanced UC demonstrated similar changes in the eosinophil count, efficacy and toxicity in both older and younger patients. In patients with a poor PS, although toxicity was significantly lower, survival was significantly worse, and neither an increase in REC nor a decrease in NER were observed, but these values showed significant changes in patients with a good PS.