Role of immunotherapy in localized muscle invasive urothelial cancer.

The standard treatment for non-metastatic muscle-invasive bladder cancer (MIBC) is cisplatin-based neoadjuvant chemotherapy followed by radical cystectomy or trimodality therapy with chemoradiation in select patients. Pathologic complete response (pCR) to neoadjuvant chemotherapy is a reliable predictor of overall and disease-specific survival in MIBC. A pCR rate of 35-40% is attained with neoadjuvant cisplatin-based chemotherapy. With the approval of immune checkpoint inhibitors (ICIs) for the treatment of metastatic urothelial cancer, these agents are now being studied in the neoadjuvant setting for MIBC. We describe the results from clinical trials using single agent ICI, ICI/ICI and ICI/chemotherapy combination therapies in the neoadjuvant setting for MIBC. These single-arm clinical trials have demonstrated safety and pCR comparable to cisplatin-based chemotherapy. Neoadjuvant ICI is a promising approach for cisplatin-ineligible patients, and the role of adding ICIs to cisplatin-based chemotherapy is also being investigated in randomized phase III clinical trials. Ongoing biomarker research to suggest a response to neoadjuvant ICIs will also guide appropriate treatment selection. We also describe the studies using ICIs for adjuvant therapy and in combination with chemoradiation.