Optimization of PD-L1 algorithm for predicting overall survival (OS) in patients with urothelial cancer (UC) treated with durvalumab monotherapy.

4530Background: PD-L1 expression is a useful biomarker in predicting response to PD-1 and PD-L1 directed immunotherapies in a variety of tumor types. In UC, studies have implicated PD-L1 expression...