This is a Phase 3, open-label, randomized trial designed to evaluate the RFS of TURBT followed by cretostimogene grenadenorepvec versus TURBT followed by surveillance for the treatment of participants with IR-NMIBC.

Participants will be randomized 1:1 to cretostimogene grenadenorepvec after TURBT (Arm A) vs surveillance after TURBT (Arm B).

Participants in Arm A will receive an induction course and then quarterly maintenance courses of cretostimogene through Month 13, if there is no disease recurrence.

Disease status will be assessed using urine cytology, cystoscopy, and directed TURBT/biopsy (if indicated) every 3 months for the first 2 years after randomization and then every 6 months for an additional year or until disease recurrence. CT Urogram/MRU every 12 months.

Participants in Arm B who recur with IR-NMIBC after TURBT and surveillance will be offered treatment with cretostimogene as per the treatment schedule in Arm A.

Inclusion Criteria:

• Pathologically confirmed IR-NMIBC, per American Urologic Association/Society of Urologic Oncology/National Comprehensive Cancer Network guidelines, within 90 days of participant randomization:

  1. Recurrent LG Ta within 12 months of prior LG or HG (HG Ta ≤ 3 cm) tumor
  2. Solitary LG Ta >3 cm tumor
  3. Multifocal LG Ta tumors
  4. Primary and solitary HG Ta ≤3 cm tumor
  5. LG T1 tumor

• All visible disease removed by TURBT within 90 days of study randomization

• Acceptable baseline organ function

Exclusion Criteria:

• High-risk NMIBC (e.g., HG T1, Recurrent or multifocal HG Ta>3cm tumor(s), CIS)
• Low-Risk NMIBC (e.g., solitary LG Ta ≤3 cm tumor)
• Disease in the prostatic urethra at any time or in the upper genitourinary tract within 24 months of randomization
• Muscle-invasive bladder cancer, locally advanced or metastatic bladder cancer
• Prior treatment with any human adenovirus serotype 5 based therapy (e.g., Adstiladrin)