IDO and PD-L1 Peptide Based Immune-Modulatory Therapeutic (IO102-IO103) in Combination With Pembrolizumab for BCG-Unresponsive or Intolerant, Non-Muscle Invasive Bladder Cancer

This study tests a vaccine-like immunotherapy (IO102-IO103) combined with pembrolizumab (an immune checkpoint inhibitor) for people with non-muscle invasive bladder cancer that has not responded to BCG — a standard immune therapy given directly into the bladder. The combination aims to train the immune system to attack remaining cancer cells. **You may be eligible if...** - You are 18 or older - You have high-risk non-muscle invasive bladder cancer confirmed by biopsy - Your cancer did not respond to or you could not tolerate two courses of BCG treatment - You are not eligible for or have declined bladder removal surgery (cystectomy) - Your bladder tumor has been fully removed (maximally resected) and you are in reasonably good health **You may NOT be eligible if...** - Your bladder cancer has invaded the muscle wall (muscle-invasive disease) - You have an active autoimmune disease requiring systemic treatment - You have had prior treatment with pembrolizumab or similar checkpoint inhibitors - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.