[Immuno-oncological therapeutic options in high-risk non-muscle invasive bladder cancer]

Immune checkpoints inhibitors in the management of high-risk non-muscle-invasive bladder cancer. A scoping review

PURPOSE

Provide the current state of trials investigating the effectiveness and safety of checkpoint inhibitors in patients with non-muscle invasive bladder cancer.

METHODS

We conducted this scoping review following the recommendations of the Joanna Briggs Institute. We searched for MEDLINE, EMBASE, CENTRAL databases, and clinical trials in search engines such as clinicaltrials.gov and clinicaltrialsregister.eu. We included clinical trials in patients over 18 years of age diagnosed with high-risk non-muscle-invasive bladder cancer who suffer treatment failure with Bacillus Calmette-Guérin (BCG). Even those who have not received prior therapy. Those clinical trials also evaluated intravenous- or intravesical-administered immune checkpoint inhibitors and those associated with BCG.

RESULTS

Thirteen clinical trials are currently being developed with immune checkpoint inhibitors as a therapeutic alternative in patients diagnosed with non-muscle-invasive urothelial carcinoma of the bladder. Five of these have not received prior therapy with bacillus Calmette-Guérin. The remaining eight studies in patients who received BCG immunotherapy with a poor response are classified as persistent, refractory, or non-responders to BCG therapy. Also, in patients who do not accept surgical management with radical cystectomy. Preliminary results from studies such as SWOG S1605 (NCT02844816) show encouraging antitumor activity and long-lasting response patients with carcinoma in situ with or without papillary disease in terms of disease-free survival and rate free of adverse events. Recently, Keynote-057 (NCT02625961) evidenced that after 36 months of follow-up, Pembrolizumab as monotherapy was tolerable and showed promising antitumor activity in patients with BCG-unresponsive non-muscle-invasive bladder cancer.

CONCLUSION

The checkpoint inhibitor response may offer a therapeutic alternative for patients diagnosed with high-risk non-muscle-invasive bladder cancer. However, the complete response rate documented in this scoping review is limited to patients with carcinoma in situ, with mild adverse effects, without reporting severity or death from the intervention.

[Adjuvant instillation therapy for non-muscle invasive bladder cancer - beyond BCG and mitomycin C]

Due to limited local efficacy of BCG and mitomycin C and the worldwide shortage of BCG, there is a clinical need to develop novel intravesical agents and application forms in order to improve the oncological outcomes in non-muscle invasive bladder cancer (NMIBC). Gemcitabine has been investigated in various clinical trials. It has proven to be superior to BCG rechallenge and MMC in BCG-unresponsive high-risk NMIBC. GemRIS is an implantable novel form of intravesical drug delivery of gemcitabine and is currently being investigated with cetrelimab, a checkpoint inhibitor, in patients with high-risk NMIBC and MIBC. Hyperthermic intravesical chemotherapy (HIVEC) leads to increased concentrations of MMC in the bladder wall and is also being investigated in various NMIBC settings. Nadofaragene firadenovec (rAd-IFN-α/Syn3) is a recombinant adenovirus that induces release of interferon-alpha in the urothelium. In a randomised study on patients with BCG-unresponsive NMIBC, it has shown relatively superior efficacy and tolerability compared with studies evaluating the role of checkpoint inhibitor monotherapies. Opportuzumab monatox is a recombinant fusion protein which binds to EpCAM and induces release of exotoxins, resulting in cytotoxic cell death. N-803 is an interleukin (IL)-15 analogue, which has been investigated in a phase 1b study in combination with BCG and has shown durable complete response in all nine patients for 72 months. It was granted breakthrough designation status by the FDA in 2019.

[BCG-induced (bacillus Calmette-Guérin) abdominal granulomatosis after occult bladder perforation]

We present the case of a 57-year-old man who developed an intraperitoneal bladder fistula with BCG-induced (bacillus Calmette-Guérin) abdominal granulomatosis after transurethral resection of a papillary non-muscle invasive bladder cancer and subsequent BCG-instillation therapy. The bladder fistula was eliminated surgically. The detection of Mycobacterium tuberculosis in the operative sample drawings as well as the histological detection of BCG-granuloma led to specific treatment and a report to the responsible health department.