Novel Delivery Systems and Pharmacotherapeutic Approaches for the Treatment of Non-muscle-invasive Bladder Cancer

Abstract

Background and objective: Therapeutic options for patients with non-muscle-invasive bladder cancer (NMIBC) have traditionally been limited to intravesical immunotherapy or chemotherapy. A considerable number of new options have been investigated in recent years. Our aim was to review the efficacy and toxicity of novel therapeutic options (results already reported or currently under investigation) for patients with NMIBC.

Methods: We assessed the efficacy of various novel therapeutic options by examining key endpoints in diverse settings, including recurrence, progression, overall survival, disease-specific survival, and complete response. We identified the principal advantages and limitations for each option. Safety was predominantly evaluated as the incidence of grade ≥3 adverse events. Our investigation focused on evidence from scientific articles and congress abstracts published in English within the past 5 yr.

Key findings and limitations: To date, pembrolizumab, nadofaragene firadenovec, and the combination of BCG with N-803 have received US Food and Drug administration approval for the treatment of BCG-unresponsive carcinoma in situ of the bladder (with or without papillary tumours). Five phase 3 trials are recruiting BCG-naïve patients with high-risk NMIBC. There is increasing interest in an ablative rather than an adjuvant approach for patients with intermediate-risk NMIBC.

Conclusions and clinical implications: Novel drugs and device-assisted drug delivery systems are on the verge of changing the treatment of NMIBC. Novel intravesical options seem to have the same efficacy with fewer adverse events in comparison to systemic therapies.

Patient summary: We reviewed new therapy options for non-muscle-invasive bladder cancer. Two agents (pembrolizumab and nadofaragene firadenovec) have been approved to date. Ongoing trials are assessing direct delivery of drugs in solution into the bladder. This route seems to have similar efficacy and fewer side effects than intravenous immunotherapy.

Keywords: Bacillus Calmette-Guérin; Clinical trials; Non–muscle-invasive bladder cancer; Treatment; Treatment-naïve; Unresponsive.