Inclusion Criteria:  Histologically confirmed, non-muscle invasive urothelial carcinoma with carcinoma in situ (CIS) (with or without papillary disease) Predominant histologic component (>50 percent) must be urothelial (transitional cell) carcinoma  Participants must have high-risk Bacillus Calmette-Guerin (BCG) - unresponsive disease, defined as:  Persistent or recurrent CIS alone or with recurrent Ta/T1 disease within 12 months of completion of adequate BCG therapy. (Ta/T1: noninvasive papillary disease/tumor invades the subepithelial connective tissue). Adequate BCG therapy is defined as one of the following: 5 of 6 doses of an initial induction course + at least 2 of 3 doses maintenance therapy 5 of 6 doses of an initial induction course + at least 2 of 6 doses of a second induction course Participant must be ineligible for or refusing a radical cystectomy All visible papillary Ta/T1 tumors must be completely resected within 60 days prior to enrollment. Eastern Cooperative Oncology Group Performance Status score of 0, 1, or 2.  Exclusion Criteria:  Current or prior history of muscle-invasive urothelial carcinoma or metastatic disease. Nodal or metastatic disease as noted on computed tomography (CT) or magnetic resonance imaging (MRI) within 3 months prior to study treatment Concomitant upper tract urothelial carcinoma as noted on CT or MRI urogram performed within 3 months prior to study treatment Prior or concomitant urothelial carcinoma of the prostatic urethra within 6 months prior to study treatment Participants with tumor-related hydronephrosis Participant has received other systemic anticancer therapy including chemotherapy, biologic therapy, immunotherapy, targeted therapy, endocrine therapy, and/or investigational agent within 4 weeks or intravesical therapy within 6 weeks of first dose of study treatment Subject has had any prior radiation to the bladder for urothelial cancer