A Study of TAR-200 in Combination With Cetrelimab, TAR-200 Alone, or Cetrelimab Alone in Participants With Non-Muscle Invasive Bladder Cancer (NMIBC) Unresponsive to Intravesical Bacillus Calmette-Guérin Who Are Ineligible for or Elected Not to Undergo Radical Cystectomy

Inclusion Criteria:

• Histologically confirmed diagnosis of persistent or recurrent high-risk non-muscleinvasive bladder cancer (HR-NMIBC), (carcinoma in situ [CIS] or tumor in situ [Tis]), with or without papillary disease (T1, high-grade Ta) or papillary diseaseonly (high-grade Ta or any T1 and absence of CIS), within 12 months of completion ofthe last dose of Bacillus Calmette-Guerin (BCG) therapy, in participants who havereceived adequate BCG. Mixed histology tumors are allowed if urothelialdifferentiation (transitional cell histology) is predominant. However, the presenceof neuroendocrine, micropapillary, signet ring cell, plasmacytoid, or sarcomatoidfeatures will make a participant ineligible. For participants with lamina propriainvasion (T1) on the screening biopsy/ transurethral resection of bladder tumor (TURBT), muscularis propria must be present in order to rule out Muscle InvasiveBladder Cancer (MIBC)

• All visible papillary disease must be fully resected (absent) prior to randomization (residual CIS is acceptable for participants eligible for Cohorts 1, 2, and 3 only)and documented in the electronic case report form (eCRF) at screening cystoscopy.For participants with papillary disease only (Cohort 4), local urine cytology atscreening must be negative or atypical (for High-Grade Urothelial Carcinoma [HGUC])

• Participants must be ineligible for or have elected not to undergo radicalcystectomy

• BCG-unresponsive high-risk NMIBC after treatment with adequate BCG therapy definedas a minimum of 5 of 6 full doses of an induction course (adequate induction) plus 2of 3 doses of a maintenance course, or at least 2 of 6 doses of a second inductioncourse

• Eastern Cooperative Oncology Group (ECOG) performance status Grade 0, 1, or 2

Exclusion Criteria:

• Presence or history of histologically confirmed, muscle-invasive, locally advanced,nonresectable, or metastatic urothelial carcinoma (that is, T2, T3, T4, and/or StageIV)

• Must not have had urothelial carcinoma or histological variant at any site outsideof the urinary bladder. Ta/T1/CIS of the upper urinary tract (including renal pelvisand ureter) is allowable if treated with complete nephroureterectomy more than 24months prior to randomization

• Received a live virus vaccine within 30 days prior to the initiation of studytreatment. Inactivated (non-live or non-replicating) vaccines approved or authorizedfor emergency use (for example, COVID-19) by local health authorities are allowed

• Active hepatitis B or C infection (for example, participants with history ofhepatitis C infection but undetectable hepatitis C virus polymerase chain reaction (PCR) test and participants with history of hepatitis B infection with positivehepatitis B surface antigen (HBsAg) antibody and undetectable PCR are allowed)

• Prior therapy with an anti-programmed-cell death 1 (PD-1), anti-PD-ligand 2 (L2)agent, or with an agent directed to another co-inhibitory T-cell receptor