Study Overview: This study is looking at how well TAR-200, combined with a medicine called cetrelimab, works against bladder cancer that has spread into the muscle. Bladder cancer is common, and some patients have a type that spreads into the muscle, which can later spread to other body parts. TAR-200 is a special drug system put into the bladder that releases a medicine called gemcitabine. Cetrelimab is a type of medicine that helps the immune system fight cancer.

Key Points:

• The study lasts up to 2 years and 6 months, with different phases (Screening, Treatment, Follow-up).
• Participants cannot have had certain treatments like chemotherapy or radiation just before joining.
• Participants must be eligible for a surgery called radical cystectomy (RC) and must meet specific health criteria.

Eligibility: To join, you must have a specific type of bladder cancer diagnosed within 120 days and meet certain health checks. You cannot join if you've had certain treatments recently or have other specific health concerns.