Combination Bacillus Calmette–Guérin and indoleamine 2,3‐dioxygenase 1 inhibitor therapy of murine orthotopic bladder cancer

Non-muscle invasive bladder cancer (NMIBC) can be managed initially with transurethral resection of a bladder tumor. In carcinoma in situ (CIS) or papillary high-grade NMIBC patients, further intravesical Bacillus Calmette-Guerin (BCG) is recommended for the prevention of recurrences. About 20% of patients suffer from BCG intolerance thereby limiting its use; up to 40% are BCG-refractory and face tumor recurrence despite initial BCG induction; finally there are BCG-resistant patients who respond to neither initial nor repeated BCG instillations [1].