Histological and combined chemoimmunostimulation therapy studies against a murine leukemia

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

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.

Immunomodulation in cancer therapeutics

Clinical verification is being obtained, with a variety of different therapeutic approaches, for the concept that anticancer treatments based on exploiting the host's own antitumor defense mechanism can be beneficial. Nevertheless, as was seen with both chemotherapeutic and radiation treatments, the benefit of single agent treatments is not great. It is anticipated that, in attempting to realize the maximal potential of anticancer treatments based on exploiting the host's own antitumor defense mechanism, it will be necessary to utilize combination therapies. For medical-ethical reasons, the ability to effectively combine such treatments with ones with proven clinical efficacy should increase the enthusiasm for the initiation of clinical trials. Chemotherapeutic agents may serve this purpose, since, contrary to the generally held tenet that anticancer chemotherapeutic agents are merely immunosuppressive, there is considerable literature describing their ability to augment antitumor host defenses. This review attempts to collate this information derived by numerous investigators employing diverse experimental approaches with a number of the most widely used anticancer chemotherapeutic agents.