All participants will be assigned the same treatment schedule. Participants will receive an induction course of 6 weekly treatments, and, if there is no disease recurrence at Week 13, participants will receive a cycle of 3 weekly treatments up to Week 15.
If there is persistent HG Ta and/or CIS at Week 13, participants may receive a second induction cycle.
If the participant has persistent but improved HG Ta and/or CIS at Week 25 or a later timepoint, the participant may receive a cycle of 3 weekly treatments of cretostimogene at the discretion of the Investigator provided that T1 or higher stage of urothelial carcinoma is not present.
If there is no disease present at Week 25 or a later timepoint, participants will receive a cycle of 3 weekly treatments every 12 weeks through Month 12.
After Month 12, participants will receive a cycle of 3 weekly treatments every 6 months through the last treatment cycle at Month 24, or until discontinuation from the study treatment.
Disease status will be assessed based on local standard of care (which may include urine cytology, cystoscopy, and directed TURBT/biopsy) every 12 weeks. CTU/MRU can be done per standard of care evaluation at investigator's discretion.
