Mycobacterium phlei cell wall-nucleic acid complex in the treatment of nonmuscle invasive bladder cancer unresponsive to bacillus Calmette-Guerin.

INTRODUCTION: Current guidelines recommend cystectomy in patients with high risk NMIBC who fail to respond to BCG. However due to the significant morbidity and mortality of the procedure, many are not candidates or refuse it. No new treatments for this indication have been approved by the US FDA since 1998. AREAS COVERED: A cell wall-nucleic acid complex (MCNA) from M. phlei has been investigated for possible application in patients with BCG refractory NMIBC. The development of this biological from the original studies is reviewed, together with the clinical trials leading to a submission to the FDA. Its efficacy and safety are presented together with comparative analysis of alternative treatments, most of which are used off-label. In addition, new combinations of standard therapies are described as well as single agents exhibiting activity against these tumors. EXPERT OPINION: MCNA has shown activity against high risk BCG refractory bladder cancer and offers an alternative to current treatments. The clinical experience remains limited and the optimal therapeutic regimen (dose, frequency) have not been firmly established. Patients and clinicians would welcome the introduction of a compound that may delay or prevent the risks and negative impact in quality of life of cystectomy and urinary diversion.