Low dose BCG as adjuvant therapy for superficial bladder cancer and literature review

Bacillus Calmette-Guérin Immunotherapy for Cancer

Bacillus Calmette–Guérin (BCG), an attenuated vaccine from Mycobacterium bovis, was initially developed as an agent for vaccination against tuberculosis. BCG proved to be the first successful immunotherapy against established human bladder cancer and other neoplasms. The use of BCG has been shown to induce a long-lasting antitumor response over all other forms of treatment against intermediate, non-invasive muscle bladder cancer Several types of tumors may now be treated by releasing the immune response through the blockade of checkpoint inhibitory molecules, such as CTLA-4 and PD-1. In addition, Toll-Like Receptor (TLR) agonists and BCG are used to potentiate the immune response against tumors. Studies concerning TLR-ligands combined with BCG to treat melanoma have demonstrated efficacy in treating mice and patients This review addresses several interventions using BCG on neoplasms, such as Leukemia, Bladder Cancer, Lung Cancer, and Melanoma, describing treatments and antitumor responses promoted by this attenuated bacillus. Of essential importance, BCG is described recently to participate in an adequate microbiome, establishing an effective response during cell-target therapy when combined with anti-PD-1 antibody, which stimulates T cell responses against the melanoma. Finally, trained immunity is discussed, and reprogramming events to shape innate immune responses are addressed.

Low-dose Bacillus Calmette-Guerin versus full-dose for intermediate and high-risk of non-muscle invasive bladder cancer: a Markov model

BACKGROUND

To compare the efficacy of low dose (27 mg) Bacillus Calmette-Guérin (BCG) and a full dose (81 mg) BCG immunotherapy for patients with intermediate and high-risk non-muscle invasive bladder cancer (NMIBC) after a typical transurethral bladder resection.

METHODS

We constructed a Markov model for a 20-year simulation of the disease to compare the overall survival of patients with intermediate and high-risk of NMIBC between the full-dose therapy (FD group) and the low-dose therapy (LD group). Base case analysis, one-way and two-way sensitivity analysis and a second-order Monte Carlo analysis were performed based on data from 15 published articles.

RESULTS

The expected overall survivals were 9.56 (9.55-9.57) years for FD group and 9.63 (9.61-9.64) years for LD group(P < 0.001). The estimated mortality in the FD group at 5, 10, and 20 years were 34.23%, 57.51% and 83.14%, respectively. The corresponding values in the LD group were 34.11%, 57.17%, 82.16%, respectively. Age-specific mortality and metastatic rate after undergoing radical cystectomy (RC) were the most two sensitive parameters in both groups. The rate of disease recurrence with disease worsening is the determining factor when choosing the optimal dose of BCG treatment.

CONCLUSIONS

A low-dose BCG treatment may act slightly better than a full-dose BCG treatment for patients with intermediate and high-risk of NMIBC. This finding will require further high-quality studies to validate.

A comparative study between full-dose and half-dose intravesical immune bacille Calmette-Guérin injection in the management of superficial bladder cancer

OBJECTIVES

To determine whether a half-dose of bacille Calmette-Guérin (BCG) can reduce toxicity without affecting its efficacy in the management of non-muscle-invasive bladder cancer.

PATIENTS AND METHODS

From January 2012 to January 2014, 80 patients with superficial bladder cancer and in the intermediate-risk group were simply randomised to receive two different doses of BCG, i.e., a full dose of 90 mg (group A) or a half-dose of 45 mg (group B). There were no significant differences in clinical and pathological characteristics between the groups. At completion of the study, 40 patients could be evaluated in each group.

RESULTS

All patients were evaluated for a follow-up of 12 months after treatment. There was no significant difference in recurrence rate (15 patients, 38%, in group A and 16, 40%, in group B) in the two groups, and no difference in progression rate of the disease, at eight patients (20%) in each group. There were significant differences between groups A and B in toxicity (grade 1 adverse events, 70% vs. 60%; grade 2, 18% vs. 7.5%, respectively). Grade 3 adverse events were only reported in group A (2.5%).

CONCLUSION

The half dose of intravesical BCG instillation can reduce the toxicity and side-effects that are associated with the treatment of superficial bladder cancer, without affecting the efficacy of therapy.

Comparing intra-arterial chemotherapy combined with intravesical chemotherapy versus intravesical chemotherapy alone: a randomised prospective pilot study for T1G3 bladder transitional cell carcinoma after bladder-preserving surgery

PURPOSE

To compare the efficacy of intra-arterial chemotherapy combined with intravesical chemotherapy versus intravesical chemotherapy alone for T1G3 bladder transitional cell carcinoma (BTCC) followed by bladder-preserving surgery.

MATERIALS AND METHODS

Sixty patients with T1G3 BTCC were randomly divided into two groups. After bladder-preserving surgery, 29 patients (age 30-80 years, 24 male and 5 female) received intra-arterial chemotherapy in combination with intravesical chemotherapy (group A), whereas 31 patients (age 29-83 years, 26 male and 5 female) were treated with intravesical chemotherapy alone (group B). Twenty-nine patients were treated with intra-arterial epirubicin (50 mg/m(2)) + cisplatin (60 mg/m(2)) chemotherapy 2-3 weeks after bladder-preserving surgery once every 4-6 weeks. All of the patients received the same intravesical chemotherapy: An immediate prophylactic was administered in the first 6 h. After that, therapy was administered one time per week for 8 weeks and then one time per month for 8 months. The instillation drug was epirubicin (50 mg/m(2)) and lasted for 30-40 min each time. The end points were tumour recurrence (stage Ta, T1), tumour progression (to T2 or greater), and disease-specific survival. During median follow-up of 22 months, the overall survival rate, tumour-specific death rate, recurrence rate, progression rate, time to first recurrence, and adverse reactions were compared between groups.

RESULTS

The recurrence rates were 10.3 % (3 of 29) in group A and 45.2 % (14 of 31) in group B, and the progression rates were 0 % (0 of 29) in group A and 22.6 % (7 of 31) in group B. There was a significant difference between the two groups regarding recurrence (p = 0.004) and progression rates (p = 0.011). Median times to first recurrence in the two groups were 15 and 6.5 months, respectively. The overall survival rates were 96.6 and 87.1 %, and the tumour-specific death rates were 0 % (0 of 29) and 13.5 % (4 of 31) in groups A and B, respectively. During the intra-arterial chemotherapy cycle, although more than 50 % patients experienced some toxicities, most were minor and reversible [grade 1-2 (46.7 %) vs. grade 1-2 (6.9 %)].

CONCLUSION

These findings suggest that combining intra-arterial chemotherapy with intravesical chemotherapy could delay tumour recurrence and progression compared with intravesical chemotherapy alone and this type treatment is relatively safe.

Bacillus Calmette-Guérin in the management of superficial bladder cancer

Intravesical Bacillus Calmette-Guérin (BCG) is the mainstay of superficial bladder cancer treatment. We performed a literature search through Medline/Pubmed using key words 'Bacillus Calmette-Guérin', 'intravesical', 'bladder neoplasm' and 'immunotherapy' for published data in the English language from 1970 to 2007 to review the current status of intravesical therapy and practice recommendations. The exact mechanism of action of intravesical BCG is yet to be elucidated. However, it appears that it is mediated by the local immune response, mainly through T-helper cell response. It reduces the recurrence rate by an average of 40% and progression by more than 20% in papillary tumors over the patients without BCG therapy. However, progression prevention is seen only in series which have used maintenance therapy at least for one year. It is effective in CIS of bladder with a response rate of more than 40% and prevention of progression in one-fourth patients. Most acceptable dose, induction treatment and maintenance therapy protocols are discussed. However, these are yet to be confirmed in large randomized trials. Intravesical BCG is well tolerated in most of the patients with mild to moderate side-effects in induction therapy; however, most patients do not complete maintenance therapy due to side-effects which is the most common concern at the present time.

Use of quasi-normal form to examine stability of tumor-free equilibrium in a mathematical model of BCG treatment of bladder cancer

Understanding the dynamics of human hosts and tumors is of critical importance. A mathematical model was developed by Bunimovich-Mendrazitsky et al., who explored the immune response in bladder cancer as an effect of BCG treatment. This treatment exploits the host's own immune system to boost a response that will enable the host to rid itself of the tumor. Although this model was extensively studied using numerical simulation, no analytical results on global tumor dynamics were originally presented. In this work, we analyze stability in a mathematical model for BCG treatment of bladder cancer based on the use of quasi-normal form and stability theory. These tools are employed in the critical cases, especially when analysis of the linearized system is insufficient. Our goal is to gain a deeper insight into the BCG treatment of bladder cancer, which is based on a mathematical model and biological considerations, and thereby to bring us one step closer to the design of a relevant clinical protocol.

Prognostic factors in patients with non-muscle-invasive bladder cancer treated with bacillus Calmette-Guérin: multivariate analysis of data from four randomized CUETO trials

OBJECTIVES

To evaluate the prognostic factors of recurrence and progression after intravesical adjuvant bacillus Calmette-Guérin (BCG) immunotherapy in patients with non-muscle-invasive bladder tumors.

METHODS

From February 1990 to May 1999, the Spanish Club Urológico Español de Tratamiento Oncológico (CUETO) group has performed four randomized phase 3 studies comparing different intravesical treatments in patients with noninvasive bladder cancer. Data from 1062 evaluable patients treated only with BCG were analyzed. Most patients received BCG once weekly for 6 consecutive weeks and a short-term BCG maintenance (once every 2 wk 6 times more). Associated tumor in situ (TIS) was found in 7.5% (n=80) of cases. There were 22.1% (n=235) patients with T1G3 tumors, 22.9% of whom (n=54) were associated with TIS. Stepwise multivariate Cox regression models with stratification by study and dose were used to assess the independent effect of predictive factors and hazard ratios (HRs) were estimated from the Cox model.

RESULTS

Multivariate analysis demonstrated that female gender (HR=1.71) compared to male gender, recurrent tumors (HR=1.9) compared to primary tumors, multiplicity, and presence of associated TIS (HR=1.54) increased the risk of recurrence. Recurrent tumors (HR=1.62) compared to primary tumors, high-grade tumors (HR=5.64) compared to G1 tumors, T1 tumors (HR=2.15) compared to Ta tumors, and recurrence at 3-mo cystoscopy (HR=4.6) increased the risk of progression.

CONCLUSION

Significant independent predictors for recurrence were female gender, history of recurrence, multiplicity, and presence of associated TIS. Age, history of recurrence, high grade, T1 stage, and recurrence at first cystoscopy were independent predictors of progression by multivariate Cox analysis.

Did patients with interstitial cystitis who failed to respond to initial treatment with bacillus Calmette-Guerin or placebo in a randomized clinical trial benefit from a second course of open label bacillus Calmette-Guerin?

PURPOSE

We evaluated safety and efficacy outcomes in a case series of subjects who received open label intravesical bacillus Calmette-Guerin after failing to respond to bacillus Calmette-Guerin or intravesical placebo in a randomized clinical trial.

MATERIALS AND METHODS

Subjects who met National Institutes of Health-National Institute of Diabetes and Digestive and Kidney Diseases criteria for IC and reported at least moderate pain and frequency were initially randomized to 6 weekly intravesical instillations of bacillus Calmette-Guerin or placebo and followed for a total of 34 weeks. At 34 weeks subjects who reported that they had not responded to treatment were offered treatment with open label bacillus Calmette-Guerin, using the same course of treatment and followup. Outcomes included a patient reported global response assessment, a 24-hour voiding diary, pain, urgency, validated interstitial cystitis symptom indexes and adverse events.

RESULTS

A total of 156 subjects elected open label bacillus Calmette-Guerin, of whom 18 (12%) withdrew during the open label series. The response rate based on the global response assessment was 18% and it was identical between those initially randomized to placebo (first course of bacillus Calmette-Guerin in the open label series) and those initially randomized to bacillus Calmette-Guerin (second course). Small improvements were observed for most secondary efficacy outcomes. Most participants reported at least 1 adverse event, primarily pain, genitourinary symptoms and gastrointestinal disturbances. However, there was no difference in adverse events between those who received the first course of bacillus Calmette-Guerin in this series compared to those who received 2 courses.

CONCLUSIONS

The low response rate for bacillus Calmette-Guerin in this open label case series further argues against the routine use of bacillus Calmette-Guerin as treatment for interstitial cystitis.

A multicentre, randomised prospective trial comparing three intravesical adjuvant therapies for intermediate-risk superficial bladder cancer: low-dose bacillus Calmette-Guerin (27 mg) versus very low-dose bacillus Calmette-Guerin (13.5 mg) versus mitomycin C

OBJECTIVE

The primary aim was to search for lower doses of Bacillus Calmette-Guerin (BCG) that are effective and have lower toxicity.

METHODS

A low dose of BCG 27 mg was compared with BCG 13.5mg, using mitomycin C (MMC) 30 mg as the third arm of comparison. A total of 430 patients with intermediate-risk superficial bladder cancer were randomised into three groups. Instillations were repeated once a week for 6 wk followed by another six instillations given once every 2 wk during 12 wk.

RESULTS

There was a significantly longer disease-free interval for BCG 27 mg versus MMC 30 mg (p=0.006). There were no statistically significant differences between BCG 27 mg and BCG 13.5mg (p=0.165) or between BCG 13.5mg and MMC 30 mg (p=0.183). Cox proportional hazards regression showed that disease-free interval in the multivariate analysis was significantly better for primary disease and treatment with BCG 27 mg. There were no significant differences among the three groups with regards to time to progression and cancer-specific survival time. Local and systemic toxicity were higher in both BCG treatment groups.

CONCLUSIONS

One third of the standard dose, BCG 27 mg, seems to be the minimum effective dose as adjuvant treatment for intermediate-risk superficial bladder cancer, being more effective than MMC 30 mg. One sixth of the standard dose, BCG 13.5mg, has the same efficacy as MMC 30 mg but it is more toxic.

Mathematical Model of BCG Immunotherapy in Superficial Bladder Cancer

Immunotherapy with Bacillus Calmette-Guérin (BCG)-an attenuated strain of Mycobacterium bovis (M. bovis) used for anti tuberculosis immunization-is a clinically established procedure for the treatment of superficial bladder cancer. However, the mode of action has not yet been fully elucidated, despite much extensive biological experience. The purpose of this paper is to develop a first mathematical model that describes tumor-immune interactions in the bladder as a result of BCG therapy. A mathematical analysis of the ODE model identifies multiple equilibrium points, their stability properties, and bifurcation points. Intriguing regimes of bistability are identified in which treatment has potential to result in a tumor-free equilibrium or a full-blown tumor depending only on initial conditions. Attention is given to estimating parameters and validating the model using published data taken from in vitro, mouse and human studies. The model makes clear that intensity of immunotherapy must be kept in limited bounds. While small treatment levels may fail to clear the tumor, a treatment that is too large can lead to an over-stimulated immune system having dangerous side effects for the patient.

T-h-2 immunity and CD3+CD45RBlow-activated T cells in mice immunized with recombinant bacillus Calmette–Guérin expressing HIV-1 principal neutralizing determinant epitope

The genetic engineering of Mycobacterium bovis-bacillus Calmette-Guérin to express foreign epitopes is an attractive strategy in the field of epitope vaccines. We constructed an 'epitope-trap vector' with Mycobacterium tuberculosis chaperonin-10 as a carrier antigen and used it to express the HIV-1 principal neutralizing determinant epitope. We also identified a new chaperonin-10 promoter that was hyperexpressive compared with the heat shock protein-65 promoter. Splenocytes from recombinant bacillus Calmette-Guérin-immunized mice showed enhanced lymphocyte proliferation and interleukin-4 (but not interferon-gamma) secretion. The recombinant bacillus Calmette-Guérin-immunized group also exhibited mild delayed-type hypersensitivity reaction and a high frequency of CD3+CD45RBlow-activated T cells, together with high titer of antiprincipal neutralizing determinant immunoglobulin G antibodies. Thus, this epitope delivery system induced strong epitope-specific T-h-2 polarization.