Bladder sparing landscape for bacillus Calmette-Guérin unresponsive bladder cancer

The treatment of bacillus Calmette-Guérin (BCG) unresponsive disease remains a challenge for urooncologists. The search for effective conservative treatments is ongoing and several new agents have been recently tested for this purpose. The aim of this manuscript was to review the last developments in this interesting field.The advent of systemic immunotherapy in the nonmuscle invasive setting promise to revolutionize the paradigm of treatment of BCG unresponsive disease. The preliminary results of the Keynote-057 trial (3 months complete response of 41% in carcinoma-in-situ patients) have led to the rapid approval of pembrolizumab from the Food and Drug Administration. Interesting results have been reported for gene therapies such as those with CG0700 and Adstiladrin, nonreplicating adenovirus able to increase the 'in situ' antitumor activity. However, larger prospective trials with longer follow-up are needed to confirm the initial findings.In summary, early radical cystectomy remains the standard treatment for BCG unresponsive patients. However, in case of patients unfit for or refusing radical cystectomy, the bladder-sparing options are continuously increasing. Although BCG-reinduction (with or without interferon) and traditional intravesical chemotherapy may represent the past, the present and the future are characterized by device-assisted therapies, systemic immunotherapy, and gene therapy.