Phase 2 Study of Pembrolizumab in Combination With Gemcitabine and Cisplatin as Neoadjuvant Therapy

Inclusion Criteria: * Be able to give written IRB approved informed consent and be able to follow protocol requirements. * Be greater than or equal to 18 years of age on day of signing informed consent. * Has a performance status of 0 or 1 on the ECOG Performance Scale * Has histologically confirmed urothelial carcinoma of the bladder; those with mixed histology, including a component of urothelial carcinoma, are eligible. Pure small cell carcinoma, pure adenocarcinoma, and pure squamous cell carcinoma are excluded. * Has clinical stage T2-T4a N0/X M0 urothelial carcinoma. Clinical T stage is based on the pre-study standard of care transurethral resection of the bladder tumor (TURBT) sample and imaging studies. * Has staging scans with abdominal/pelvic CT or MRI scan and CT scan or x-ray of the chest within 4 weeks prior to treatment initiation * Be a medically appropriate candidate for radical cystectomy as determined by an attending urologist and be planning to receive cystectomy. * Has had no prior systemic cytotoxic chemotherapy for urothelial carcinoma (prior intravesicular chemotherapies are permitted) * Patients must have tumor tissue from transurethral resection of the bladder tumor (TURBT) available for submission that is sufficient for correlative testing, and agree to submission of a paraffin block or 20 formalin-fixed paraffin embedded (FFPE) slides of 5-10 microns in thickness. Patients must also agree to submission of tissue from cystectomy. * Demonstrate adequ…