Treatment Strategies for BCG Unresponsive Non-muscle Invasive Bladder Cancer

Bacillus Calmette-Guérin (BCG) is the standard treatment for patients with non-muscle invasive bladder cancer (NMIBC). Although this therapy has been effective, BCG resistance poses a significant challenge, highlighting the need for alternative treatment options. Possible alternative treatments include intravesical chemotherapy, immunotherapy, antibody-drug conjugates, device-assisted therapies, gene therapy, and radiotherapy. Although radical cystectomy is recommended after BCG failure, its high morbidity and considerable impact on patients' lives underscore the necessity of developing new treatment strategies. This review provides an outline of the current knowledge and ongoing research on alternative treatments for BCG-unresponsive high-risk NMIBC, aiming to improve patient outcomes. Considering the current global shortage of BCG, it is essential to prioritize alternative therapies as treatment options for patients with BCG-unresponsive NMIBC.