The role of mycobacterial cell wall nucleic acid complex in the treatment of bacillus Calmette–Guérin failures for non-muscle-invasive bladder cancer

Abstract

Introduction: The treatment of high-risk non-muscle-invasive bladder cancer (NMIBC) utilizes transurethral resection followed by adjuvant intravesical immunotherapy or chemotherapy. Intravesical bacillus Calmette–Guérin (BCG) is the mainstay of adjuvant immunotherapy, but there are limited nonsurgical options for patients that fail this treatment. Mycobacterial cell wall nucleic acid complex (MCNA) is an immunotherapeutic agent utilized primarily after failure of intravesical BCG. The purpose of this paper is to provide a comprehensive review of the published literature regarding MCNA. Methods: A literature review was performed and identified studies indexed in MEDLINE® related to utilization of MCNA for patients with NMIBC. Results: Two trials assessed the efficacy of MCNA in patients with NMIBC, comprising a total of 184 patients. Most patients had carcinoma in situ (CIS) with (26%) or without (52%) concomitant papillary tumors. A minority of patients had only papillary tumors (22%). Most patients (95%) previously received BCG or other intravesical therapy prior to receiving MCNA. In the largest available trial, 25% and 19% of patients had no evidence of residual cancer in 1 and 2 years following initiation of MCNA. A total of 2.3% of patients had adverse events (AEs) leading to delay or discontinuation of therapy and 66% of patients had mild drug-related AEs. Conclusion: Based on analysis of available published data, MCNA offers a durable response for a small proportion of patients that have failed prior intravesical therapy. There still exists a large unmet need for nonsurgical treatment options for patients with NMIBC who have failed adjuvant intravesical therapies.