This clinical trial is focused on studying a type of bladder cancer known as Non-Muscle Invasive Bladder Cancer (NMIBC). This form of cancer affects the bladder but does not invade the muscle layer. The study is exploring the effectiveness and safety of different treatments for patients whose cancer has not responded to a common treatment called Intravesical Bacillus Calmette-Guérin (BCG) and who are not eligible for or have chosen not to undergo a major surgery called radical cystectomy. The treatments being tested include a drug-device combination called TAR-200, which is placed in the bladder, and a medication called Cetrelimab, which is given through an infusion into the vein. The study will look at these treatments both separately and in combination.

The purpose of the study is to evaluate how well these treatments work in eliminating cancer and preventing its return. Participants will be divided into different groups to receive either TAR-200 with Cetrelimab, TAR-200 alone, or Cetrelimab alone. The study will also include a group receiving TAR-200 alone for those with a specific type of papillary disease. Throughout the study, participants will undergo regular check-ups, including procedures like cystoscopies, which allow doctors to look inside the bladder, and biopsies, which involve taking small samples of tissue for examination. These procedures help in assessing the response to the treatment and monitoring any changes in the condition.

The study will last for several years, with participants receiving treatment over a period of time and being monitored for any signs of cancer recurrence or progression. The trial aims to provide valuable information on the potential benefits and safety of these treatments for patients with high-risk NMIBC. By participating, individuals contribute to research that may improve future treatment options for this type of bladder cancer.