For a patient with metastatic urothelial cancer who has progressed on platinum-based chemotherapy, do you test for tumor PD-L1 expression prior to choosing atezolizumab as second-line treatment?   

In the IMvigor 210 trial, increased PD-L1 expression in patients’ tumors was associated with response to atezolizumab, but some patients whose tumors were negative for PD-L1 still responded.  Do you switch all patients to atezolizumab after progression on platinum, or only those with PD-L1 expression?

Answer from: Medical Oncologist at Academic Institution