Number of Participants Who Experience a Dose-limiting Toxicity (DLT)

Any of the following toxicities will be considered a DLT: Hematuria leading to clot or obstruction; Grade (Gr) 4 thrombocytopenia; Gr 3 thrombocytopenia associated with clinically significant bleeding; Febrile neutropenia for more than 1 hour; Other Gr ≥3 hematologic toxicity lasting \>7 days; Nonhematologic AE ≥Gr 3 (with exceptions); ≥Gr 2 pneumonitis/ interstitial lung disease; Any ≥Gr 3 nonhematologic laboratory value if clinically significant medical intervention is required, leads to hospitalization, persists for \>7 days, results in a drug induced liver injury, or elevated aspartate aminotransferase (AST) or alanine aminotransferase (ALT) lab value \>8 ×upper limit of normal (ULN) regardless of duration and AST or ALT elevation 5 × to 8 × ULN that persists for greater than 2 weeks; Recurrent Gr 2 AE resulting in \>2 weeks delay in receiving the next treatment dose; Any intervention-related toxicity that results in study intervention discontinuation; Gr 5 toxicity or AE.

Up to approximately 5 weeks

Number of Participants Who Experience One or More Adverse Events (AEs)

An AE is defined as any unfavorable and unintended sign, symptom, disease, or worsening of preexisting condition temporally associated with study treatment and irrespective of causality to study treatment.

Up to approximately 24 months

Number of Participants Who Discontinue Study Treatment Due to AEs

An AE is defined as any unfavorable and unintended sign, symptom, disease, or worsening of preexisting condition temporally associated with study treatment and irrespective of causality to study treatment.

Up to approximately 12 months

Complete Response Rate (CRR)

CR is defined as the absence of all of the following as determined by local assessment using urine cytology, cystoscopy, biopsy and radiology assessments as applicable: * High-risk non-muscle invasive urothelial cancer (UC) (defined as high-grade \[HG\] noninvasive papillary \[Ta\], carcinoma in situ \[CIS\], or any submucosal invasive \[T1\] disease of the bladder, urethra, or upper tract \[ureters, renal pelvis\]) * Any muscle invasive tumor (T2) or greater in the bladder, including transurethral prostate stromal invasion of UC, or in the upper tract (ureters, renal pelvis) * Metastatic UC, defined as: * Regional lymph node metastasis of UC (N1 or greater) * Distant lymph node or visceral metastasis of UC (M1)

Up to approximately 3 months