New immunotherapies for high-risk non-muscle invasive bladder cancer: Current state and future perspectives

Background: The standard treatment for high-risk non-muscle invasive bladder tumors (NMIBT) is transurethral resection of the bladder and BCG instillations. However, responses are limited, and new therapeutic alternatives for these patients are required. The results of checkpoint inhibitors in advanced tumors have led to interest in the use of these molecules in NMIBT.

Methods: We conducted a search on PubMed using the terms «bladder cancer» and «check point inhibitors». We have used the search engines clinicaltrials.gov and clinicaltrialsregister.eu for the search of clinical trials.

Results: There are currently 5 trials in progress on BCG untreated patients. There are no results available. As for BCG non-responders, there are 15 ongoing trials, two of them with preliminary results: Keynote 057, with promising results with pembrolizumab, which has led the FDA to approve its use in January 2020, and SWOG S1605, which has shown similar results with atezolizumab. Other trials are using intravesical administration of these drugs, which is an attractive option if it is effective for cancer control.

Conclusions: Checkpoint inhibitors offer a new possibility for patients who do not respond to BCG. These will probably be used in the future for previously BCG untreated patients. Preliminary data from clinical trials show promising results. A good understanding of these molecules by urologists and the creation of multidisciplinary teams are crucial in order to offer the best therapeutic alternatives to these patients.