Phase II Trial of Palbociclib in Patients With Metastatic Urothelial Cancer After Failure of First-Line Chemotherapy

This multicenter phase II trial will evaluate palbociclib (PD-0332991) in patients with metastatic urothelial carcinoma (UC) with cyclin-dependent kinase inhibitor 2A (CDKN2A) (also referred to as p16) loss and positive Retinoblastoma (Rb) expression after failure of first-line chemotherapy. The study will enroll up to 40 patients to identify 36 evaluable patients, using a Simon's two-stage design, with a primary endpoint of progression free survival (PFS) at 4 months (PFS4). Secondary objectives include estimating median PFS, overall survival (OS), response rate (RR) and exploratory objectives include an evaluation of molecular predictors of response and resistance.