Trial of Intravesical Measles Virotherapy in Patients With Bladder Cancer Who Are Undergoing Radical Cystectomy

Inclusion Criteria: * Diagnosis of Urothelial carcinoma (UC) of the bladder, with histologic confirmation of primary UC pathology; indication for Radical cystectomy (RC); ineligibility for platinum-based neoadjuvant chemotherapy * ECOG Performance Status (PS) 0 or 1. * Ability to provide informed consent. * Willingness to comply with all required protocol procedures including providing biologic specimens and returning to the clinical study site for follow up visits. * Performance status sufficient to undergo RC (in the opinion of the enrolling urologist) including adequate hematological, liver and kidney function * Must be willing to implement contraception throughout study and for 30 days following RC. Exclusion Criteria: * Variant UC pathology including but not limited to micropapillary, signet ring,sarcomatoid, and clear cell variants. * Patients with any other prior malignancy are not allowed except for the following: History of or concurrent non-invasive UC involving a portion of urinary tract outside of the bladder; Adequately treated basal cell or squamous cell skin cancer; In situ cervical cancer; Adequately treated Stage I or II cancer from which the patient is currently incomplete remission or other cancer from which the patient has been disease-free for 2 years. * Prior treatment with an anti-PD-1, anti-PD-L1, anti-PD-L2, anti-CTLA-4 antibody, or any other antibody or drug specifically targeting T-cell co-stimulation or immune checkpoint pathways. * Any of the following prior therapy: Chemotherapy ≤ 3 weeks prior to registration. Biologic therapy ≤ 4 weeks prior to registration. Radiation therapy ≤ 3 weeks prior to registration * Other concurrent investigational therapy (utilized for a non-FDA-approved indication and in the context of a research investigation). * Pregnant women. * Nursing women. * Men or women of childbearing potential who are unwilling to employ adequate contraception during treatment and 8 weeks following the completion of study drug treatment. * Allergy to measles vaccine or history of severe reaction to prior measles vaccination. * History of organ transplantation.