Validation of a drug-based score in advanced urothelial carcinoma treated with pembrolizumab.

To validate a 'drug score' that stratifies patients receiving immunotherapy based on concomitant medications (antibiotics/proton pump inhibitors/corticosteroids) in urothelial carcinoma (UC). We assessed oncological outcomes according to the drug score in 242 patients with advanced UC treated with pembrolizumab. The drug score classified patients into three risk groups with significantly different survivals. Heterogeneous treatment effect analyses showed that the primary cancer site (bladder UC [BUC] or upper-tract UC [UTUC]) significantly affected the prognostic capability of the drug score; it significantly correlated with survivals in BUC, while there were no such correlations in UTUC. A drug score was examined in advanced UC treated with pembrolizumab and was validated in BUC but not in UTUC.