Antitumor Efficacy of Intravesical BCG, Gemcitabine, Interferon-α and Interleukin-2 as Mono- or Combination-Therapy for Bladder Cancer in an Orthotopic Tumor Model

The Impact of a New Interleukin-2-Based Immunotherapy Candidate on Urothelial Cells to Support Use for Intravesical Drug Delivery

(1) Background: The intravesical instillation of interleukin-2 (IL-2) has been shown to be very well tolerated and promising in patients with bladder malignancies. This study aims to confirm the use of a new IL-2 containing immunotherapy candidate as safe for intravesical application. IL-2, produced in mammalian cells, is glycosylated, because of its unique solubility and stability optimized for intravesical use. (2) Materials and Methods: Urothelial cells and fibroblasts were generated out of porcine bladder and cultured until they reached second passage. Afterwards, they were cultivated in renal epithelial medium (REM) and Dulbecco’s modified Eagles medium (DMEM) with the IL-2 candidate (IMS-Research) and three more types of human interleukin-2 immunotherapy products (IMS-Pure, Natural IL-2, Aldesleukin) in four different concentrations (100, 250, 500, 1000 IU/mL). Cell proliferation was analyzed by water soluble tetrazolium (WST) proliferation assay after 0, 3, and 6 days for single cell culture and co-culture. (3) Results: Proliferation assays showed that all IL-2 products induced very similar cultivation results and none of the IL-2 variants had a negative impact on the proliferation of urothelial cells and fibroblast in either concentration. (4) Conclusion: Human recombinant glycosylated IL-2 as well as human non-glycosylated IL-2 have no negative influence on the tissue cell proliferation of porcine urothelial cells and fibroblasts in vitro and represent a promising and innovative potential intravesical therapy candidate for patients in high need.

Updates on the use of intravesical therapies for non-muscle invasive bladder cancer: how, when and what

INTRODUCTION

Intravesical therapy has been an important aspect of the management of non-muscle invasive bladder cancer (NMIBC) for 40 years. Bacillus Calmette-Guerin (BCG) is considered standard of care for intermediate and high-grade non-invasive disease, yet understanding the nuances of subsequent intravesical therapy is important for any provider managing bladder cancer. Herein, we review the literature and describe optimal use of intravesical therapies for NMIBC.

METHODS

A comprehensive search of the medical literature was performed and highlighted in this review of intravesical therapy for NMIBC.

RESULTS

Post-resection intravesical Mitomycin C therapy for low-risk disease remains an important component of care, and gemcitabine now has level-one evidence demonstrating efficacy in this setting but is not yet a guideline recommendation. BCG intravesical therapy remains the most effective therapy preventing recurrence and progression of intermediate and high-risk NMIBC. Adequately characterizing BCG-failure is critical in determining the next step in management which includes radical cystectomy, additional intravesical immunotherapy, chemotherapy with intravesical gemcitabine ± docetaxel and clinical trials.

CONCLUSIONS

Intravesical therapy remains the mainstay of treatment for NMIBC and bladder preservation. Intravesical induction BCG followed by maintenance therapy remains standard of care for intermediate and high-risk patients. Detailing the timing and characteristics of recurrence after intravesical therapy is crucial in determining subsequent treatment recommendations. Current clinical trials focus on systemic immunotherapy and enhancing the intravesical immune response by augmenting the delivery mechanism.

Curcumin as Treatment for Bladder Cancer: A Preclinical Study of Cyclodextrin-Curcumin Complex and BCG as Intravesical Treatment in an Orthotopic Bladder Cancer Rat Model

Objective

To evaluate the antitumor effect of cyclodextrin-curcumin complex (CDC) on human and rat urothelial carcinoma cells in vitro and to evaluate the effect of intravesical instillations of CDC, BCG, and the combination in vivo in the AY-F344 orthotopic bladder cancer rat model. Curcumin has anticarcinogenic activity on urothelial carcinoma and is therefore under investigation for the treatment of non-muscle invasive bladder cancer. Curcumin and BCG share immunomodulating pathways against urothelial carcinoma.

Methods

Curcumin was complexed with cyclodextrin to improve solubility. Four human urothelial carcinoma cell lines and the AY-27 rat cell line were exposed to various concentrations of CDC in vitro. For the in vivo experiment, the AY-27 orthotopic bladder cancer F344 rat model was used. Rats were treated with consecutive intravesical instillations of CDC, BCG, the combination of CDC+BCG, or NaCl as control.

Results

CDC showed a dose-dependent antiproliferative effect on all human urothelial carcinoma cell lines tested and the rat AY-27 urothelial carcinoma cell line. Moreover, intravesical treatment with CDC and CDC+BCG results in a lower percentage of tumors (60% and 68%, respectively) compared to BCG (75%) or control (85%). This difference with placebo was not statistically significant (p=0.078 and 0.199, respectively). However, tumors present in the placebo and BCG-treated rats were generally of higher stage.

Conclusions

Cyclodextrin-curcumin complex showed an antiproliferative effect on human and rat urothelial carcinoma cell lines in vitro. In the aggressive orthotopic bladder cancer rat model, we observed a promising effect of CDC treatment and CDC in combination with BCG.

Prospects and progress of immunotherapy for bladder cancer

INTRODUCTION

With recent advances in immunooncology and the introduction of checkpoint inhibitors into clinical practice for many cancers, the treatment landscape of urothelial carcinoma has changed dramatically and will continue to change further. Currently, a number of compounds and combinations are under investigation in numerous clinical trials and various clinical scenarios for bladder cancer. Areas covered: In this review, the authors provide an overview of the history and rationale for immunotherapy in bladder cancer. They also provide the currently available data evaluating checkpoint inhibitors for bladder cancer, and discuss ongoing trials and future perspectives for urothelial carcinoma treatment. Expert opinion: The introduction of checkpoint inhibitors into the management of bladder cancer marks a significant milestone for this disease. Checkpoint inhibitors have the potential to impact patients across multiple disease states from non-muscle-invasive disease to metastatic tumors refractory to conventional treatment. That being said, validated biomarkers, including genetic signatures, to accurately predict response, and the establishment of optimal sequencing and combination of these immunotherapeutic agents with chemo/radiotherapy are urgently needed.

A Hydrogel-Based Epirubicin Delivery System for Intravesical Chemotherapy

This study aimed to examine the efficacy of epirubicin-loaded gelatin hydrogel (EPI-H) in the treatment of superficial urothelium carcinoma. Hydrogel was prepared by Schiff base-crosslinking of gelatin with glutaraldehyde. EPI-H exhibited high entrapment efficiency (59.87% ± 0.51%). EPI-H also increased epirubicin accumulation in AY-27 cells when compared with the effect of aqueous solutions of epirubicin (EPI-AQ); respective epirubicin-positive cell counts were 69.0% ± 7.6% and 38.3% ± 5.8%. EPI-H also exhibited greater cytotoxicity against AY-27 cells than that of EPI-AQ; IC50 values were 13.1 ± 1.1 and 7.5 ± 0.3 μg/mL, respectively. Cystometrograms showed that EPI-H reduced peak micturition, threshold pressures, and micturition duration, and that it increased bladder compliance more so than EPI-AQ. EPI-H enhanced epirubicin penetration into basal cells of urothelium in vivo, whereas EPI-AQ did so only to the umbrella cells. EPI-H inhibited tumor growth upon intravesical instillation to tumor-bearing bladder of F344 rats, inducing higher levels of caspase-3 expression than that observed with EPI-AQ treatment; the number of caspase-3 positive cells in treated urothelium carcinoma was 13.9% ± 4.0% (EPI-AQ) and 34.1% ± 1.0%, (EPI-H). EPI-H has value as an improved means to administer epirubicin in intravesical instillation treatments for bladder cancer.

Future directions in bladder cancer immunotherapy: towards adaptive immunity

The clinical management of bladder cancer has not changed significantly in several decades. In particular, intravesical bacillus Calmette-Guérin (BCG) immunotherapy has been a mainstay for high-risk nonmuscle invasive bladder cancer since the late 1970s/early 1980s. This is despite the fact that bladder cancer has the highest recurrence rates of any cancer and BCG immunotherapy has not been shown to induce a tumor-specific immune response. We and others have hypothesized that immunotherapies capable of inducing tumor-specific adaptive immunity are needed to impact bladder cancer morbidity and mortality. This article summarizes the preclinical and clinical development of bladder cancer immunotherapies with an emphasis on the last 5 years. Expected progress in the near future is also discussed.

A Multimodal Imaging Approach for Longitudinal Evaluation of Bladder Tumor Development in an Orthotopic Murine Model

Bladder cancer is the fourth most common malignancy amongst men in Western industrialized countries with an initial response rate of 70% for the non-muscle invasive type, and improving therapy efficacy is highly needed. For this, an appropriate, reliable animal model is essential to gain insight into mechanisms of tumor growth for use in response monitoring of (new) agents. Several animal models have been described in previous studies, but so far success has been hampered due to the absence of imaging methods to follow tumor growth non-invasively over time. Recent developments of multimodal imaging methods for use in animal research have substantially strengthened these options of in vivo visualization of tumor growth. In the present study, a multimodal imaging approach was addressed to investigate bladder tumor proliferation longitudinally. The complementary abilities of Bioluminescence, High Resolution Ultrasound and Photo-acoustic Imaging permit a better understanding of bladder tumor development. Hybrid imaging modalities allow the integration of individual strengths to enable sensitive and improved quantification and understanding of tumor biology, and ultimately, can aid in the discovery and development of new therapeutics.

Low-dose bacille Calmette-Guérin for non-muscle-invasive bladder cancer: Results of a prospective study

Objective

To evaluate the efficacy and safety of low-dose (45 mg) intravesical bacille Calmette–Guérin (BCG) therapy in the treatment of patients with non-muscle-invasive bladder cancer (NMIBC), as intravesical BCG is the most acceptable adjuvant therapy for NMI transitional cell carcinoma of the bladder. However, in the standard regimen, undesirable effects are the main cause of treatment discontinuation.

Patients and methods

The present study included 37 men with primary NIMBC. All patients underwent complete TURB and 2 weeks later, a 6-week course of 45 mg BCG diluted in 50 mL isotonic saline was instilled into the bladder and retained for 2 h. Patients were evaluated for BCG efficacy (recurrence with or without progression) and safety by documentation of minor and/or major side-effects.

Results

There were no major or severe side-effects and no treatment discontinuations. Local adverse effects occurred in 20 patients, while systemic effects, in the form of fever, occurred in six patients (16.2%). There was recurrence in 14 patients (37.8%) after 18–34 months, with disease progression (muscle invasion) in four (10.8%) after 6–18 months. The recurrence index was 0.39/100 patients/month and the mean (range) tumour-free period was 30.97 (7–36) months.

Conclusion

Low-dose BCG intravesical therapy is an effective adjuvant treatment in NMIBC. However, this needs to be validated in future studies and in comparison with other proposed doses and/or regimens.

Nonpathogenic Mycobacterium brumae Inhibits Bladder Cancer Growth In Vitro, Ex Vivo, and In Vivo

BACKGROUND

Bacillus Calmette-Guérin (BCG) prevents tumour recurrence and progression in non-muscle-invasive bladder cancer (BC). However, common adverse events occur, including BCG infections.

OBJECTIVE

To find a mycobacterium with similar or superior antitumour activity to BCG but with greater safety.

DESIGN

In vitro, ex vivo, and in vivo comparisons of the antitumour efficacy of nonpathogenic mycobacteria and BCG.

INTERVENTION

The in vitro antitumour activity of a broad set of mycobacteria was studied in seven different BC cell lines. The most efficacious was selected and its ex vivo capacity to activate immune cells and its in vivo antitumour activity in an orthotopic murine model of BC were investigated.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Growth inhibition of BC cells was the primary outcome measurement. Parametric and nonparametric tests were use to analyse the in vitro results, and a Kaplan-Meier test was applied to measure survival in mycobacteria-treated tumour-bearing mice.

RESULTS AND LIMITATIONS

Mycobacterium brumae is superior to BCG in inhibiting low-grade BC cell growth, and has similar effects to BCG against high-grade cells. M. brumae triggers an indirect antitumour response by activating macrophages and the cytotoxic activity of peripheral blood cells against BC cells. Although no significant differences were observed between BCG and M. brumae treatments in mice, M. brumae treatment prolonged survival in comparison to BCG treatment in tumour-bearing mice. In contrast to BCG, M. brumae does not persist intracellularly or in tumour-bearing mice, so the risk of infection is lower.

CONCLUSIONS

Our preclinical data suggest that M. brumae represents a safe and efficacious candidate as a therapeutic agent for non-muscle-invasive BC.

PATIENT SUMMARY

We investigated the antitumour activity of nonpathogenic mycobacteria in in vitro and in vivo models of non-muscle-invasive bladder cancer. We found that Mycobacterium brumae effectively inhibits bladder cancer growth and helps the host immune system to eradicate cancer cells, and is a promising agent for antitumour immunotherapy.

Inflammation and Urothelial Bladder Cancer: What we Need to Known? (Review)

 The association between inflammation and bladder cancer has been debated in several studies, highlighting that inflammation may be a crucial component both in tumor development or progression. On the other hand, several authors suggest that the presence of an inflammatory cell infiltrate within the urothelial bladder cancer is a good prognostic predictor in terms of recurrence-free survival time. The question is: What is the prognostic role of inflammation in patients affected by urothelial bladder cancer? On one hand, chronic inflammation should be considered a risk factor in developing bladder cancer, as demonstrated by Schistosoma haematobium infection and, on the other hand, the inflammation induced by the Bacillus Calmette-Guérin intravesical therapy has a protective effect on cancer recurrence. Recently, some authors highlight that the presence of an inflammatory cell infiltrate within the urothelial bladder cancer is a good prognostic predictor in terms of recurrence-free survival time, due to the host generating angiogenic stimulation of a local inflammatory reaction against cancer. This is probably due to the angiogenetic stimulation of a local inflammatory reaction generated by the host against superficial bladder cancer. However, the debate is still open. This review will summarize recent data regarding inflammation and urothelial cell carcinoma, with special emphasis on the role that the inflammatory response is likely to have on recurrence risk and progression in superficial bladder cancer patients.

Thiotepa versus Bacille Calmette-Guérin in Non-Muscle Invasive Bladder Cancer

OBJECTIVE

The efficacy of intravesical thiotepa was evaluated compared with administration of Bacille Calmette-Guérin (BCG) in non-muscle invasive bladder cancer.

PATIENTS

In this multicenter, prospective, randomized study, eligible patients were those with proven non-muscle invasive bladder cancer. All patients were randomly allocated to Group A, receiving intravesical thiotepa (at a dose of 30 mg/30 ml) once weekly for 9 consecutive weeks and then monthly for 12 months or Group B, receiving intravesical Bacille Calmette-Guérin (Connaught strain, 80 mg/50 ml) over a 9-week induction course and each week for 3 weeks at 3, 6 and 12 months. Outcome measures were recurrence rate, time to first recurrence and progression rate. Treatment-related complications were also evaluated.

RESULTS

Seventy-two participants were enrolled, 36 for each group, 17 in Group A developed disease recurrence versus 25 of those in Group B (p < 0.05). There was no statistically significant difference in mean time to the first recurrence (Group A, 4.2 months; Group B, 4.1 months; p > 0.05). Seven of 17 (41%) patients in Group A and 16 of 25 (64%) patients in Group B had disease progression and underwent radical cystectomy (p < 0.05). Both intravesical administrations were generally well tolerated.

CONCLUSION

Thiotepa is a promising intravesical agent for treatment of non-muscle invasive bladder cancer.