Phase I trial of intravesical gemcitabine in bacillus Calmette-Guérin-refractory transitional-cell carcinoma of the bladder

Real-world efficacy of adjuvant single-agent intravesical gemcitabine for non-muscle invasive bladder cancer

INTRODUCTION

Failure, intolerance, or shortage of bacillus Calmette-Guerin (BCG) treatment for patients with high-risk (HR) non-muscle invasive bladder cancer (NMIBC) leave many facing the prospect of radical cystectomy (RC). However, despite the lack of large-scale randomized controlled studies with single-agent intravesical gemcitabine (Gem), it has emerged as a popular salvage agent after BCG failure or even a treatment alternative to BCG.

AREAS COVERED

1. Characterization of treatment regimen details pertaining to single-agent intravesical adjuvant Gem use among disease states of NMIBC characterized by risk and BCG exposure. 2. Comparison of safety and efficacy of Gem according to risk category, type of tumor (papillary vs. carcinoma in situ (CIS)), and tumor grades.

EXPERT OPINION

Two randomized studies in early BCG failure disease demonstrate that single-agent Gem has superior efficacy versus repeated BCG therapy or mitomycin C. Studies enrolling patients with predominantly papillary disease without CIS, intermediate-risk (IR) disease, and less BCG exposure appear to derive the highest benefits from adjuvant Gem in terms of recurrence and progression. However, studies with cohorts enriched for a predominance of CIS, HR disease and/or more extensive BCG failure have poorer 2-year recurrence free survival and a somewhat higher risk of progression and RC.

BCG-Unresponsive Non-Muscle-Invasive Bladder Cancer: Current Treatment Landscape and Novel Emerging Molecular Targets

Urothelial carcinoma (UC), the sixth most common cancer in Western countries, includes upper tract urothelial carcinoma (UTUC) and bladder carcinoma (BC) as the most common cancers among UCs (90-95%). BC is the most common cancer and can be a highly heterogeneous disease, including both non-muscle-invasive (NMIBC) and muscle-invasive (MIBC) forms with different oncologic outcomes. Approximately 80% of new BC diagnoses are classified as NMIBC after the initial transurethral resection of the bladder tumor (TURBt). In this setting, intravesical instillation of Bacillus Calmette-Guerin (BCG) is the current standard treatment for intermediate- and high-risk patients. Unfortunately, recurrence occurs in 30% to 40% of patients despite adequate BCG treatment. Radical cystectomy (RC) is currently considered the standard treatment for NMIBC that does not respond to BCG. However, RC is a complex surgical procedure with a recognized high perioperative morbidity that is dependent on the patient, disease behaviors, and surgical factors and is associated with a significant impact on quality of life. Therefore, there is an unmet clinical need for alternative bladder-preserving treatments for patients who desire a bladder-sparing approach or are too frail for major surgery. In this review, we aim to present the strategies in BCG-unresponsive NMIBC, focusing on novel molecular therapeutic targets.

Cost-Effectiveness of Nadofaragene Firadenovec and Pembrolizumab in Bacillus Calmette-Guérin Immunotherapy Unresponsive Non-Muscle Invasive Bladder Cancer

OBJECTIVES

Nadofaragene firadenovec is a gene therapy for bacillus Calmette-Guérin (BCG)-unresponsive non-muscle-invasive bladder cancer (NMIBC) undergoing Food and Drug Administration review. Pembrolizumab is approved for treating patients with BCG-unresponsive NMIBC with carcinoma in situ (CIS). We evaluated the cost-effectiveness of these treatments compared with a hypothetical therapeutic alternative, at a willingness-to-pay threshold of $150 000 per quality-adjusted life-year (QALY) gained, in CIS and non-CIS BCG-unresponsive NMIBC populations.

METHODS

We developed a Markov cohort simulation model with a 3-month cycle length and lifetime horizon to estimate the total costs, QALYs, and cost per additional QALY from the health sector perspective. Clinical inputs were informed by results of single-arm clinical trials evaluating the treatments, and systematic literature reviews were conducted to obtain other model inputs. Sensitivity analyses were conducted to assess uncertainty in model results.

RESULTS

Nadofaragene firadenovec, at a placeholder price 10% higher than the price of pembrolizumab, had an incremental cost-effectiveness ratio of $263 000 and $145 000 per QALY gained in CIS and non-CIS populations, respectively. Pembrolizumab had an incremental cost-effectiveness ratio of $168 000 per QALY gained for CIS. A 5.4% reduction in pembrolizumab's price would make it cost-effective. The model was sensitive to many inputs, especially to the probabilities of disease progression, initial treatment response and durability, and drug price.

CONCLUSIONS

The cost-effectiveness of nadofaragene firadenovec will depend upon its price. Pembrolizumab, although not cost-effective in our base-case analysis, is an important alternative in this population with an unmet medical need. Comparative trials of these treatments are warranted to better estimate cost-effectiveness.

Current treatments for BCG failure in non-muscle invasive bladder cancer (NMIBC)

The treatment of choice for high-risk non-muscle invasive bladder cancer (NMIBC) is bacillus Calmette-Guérin (BCG). However, when this fails, the indicated treatment is radical cystectomy. In recent years, trials are being developed with various drugs to avoid this surgery in patients with BCG failure. The aim of this article is to update the treatments under study for bladder preservation in this patient population. Non-systematic review, searching PubMed with the terms "Bladder cancer", "Non-muscle invasive bladder cancer", "NMIBC", "BCG", "BCG-refractory", "Mitomycin C", "MMC", "Hyperthermia", "Electromotive Drug Administration", "EMDA". We used the search engines clinicaltrials.gov and clinicaltrialsregister.eu to find clinical trials. The only intravesical drug approved by the Food and Drug Administration (FDA) for carcinoma in situ (CIS) after failure to BCG is Valrubicin. Recently, the FDA has approved intravenous Pembrolizumab, following the publication of preliminary data from the KEYNOTE-057 study. Atezolizumab has demonstrated similar preliminary efficacy results. Only microwave-induced chemohyperthermia and EMDA-MMC (Electromotive Drug Administration) are recognized as alternatives in European guidelines. Other options under investigation are taxanes and gemcitabine, alone or in combination, recombinant viruses and device-assisted intravesical chemohyperthermia. The results of new drugs are promising, with a large number of trials underway. Knowing the mechanisms of resistance to BCG is essential to explore new therapeutic options.

Hyperthermia Improves Solubility of Intravesical Chemotherapeutic Agents

BACKGROUND: Nearly 70% of all new cases of bladder cancer are non-muscle invasive disease, the treatment for which includes transurethral resection followed by intravesical therapy. Unfortunately, recurrence rates approach 50% in part due to poor intravesical drug delivery. Hyperthermia is frequently used as an adjunct to intravesical chemotherapy to improve drug delivery and response to treatment. OBJECTIVE: To assess the solubility profile of intravesical chemotherapies under varying conditions of pH and temperature. METHODS: Using microplate laser nephelometry we measured the solubility of three intravesical chemotherapy agents (mitomycin C, gemcitabine, and cisplatin) at varying physical conditions. Drugs were assessed at room temperature (23°C), body temperature (37°C), and 43°C, the temperature used for hyperthermic intravesical treatments. To account for variations in urine pH, solubility was also investigated at pH 4.00, 6.00, and 8.00. RESULTS: Heat incrementally increased the solubility of all three drugs studied. Conversely, pH largely did not impact solubility aside for gemcitabine which showed slightly reduced solubility at pH 8.00 versus 6.00 or 4.00. Mitomycin C at the commonly used 2.0 mg/mL was insoluble at room temperature, but soluble at both 37 and 43°C. CONCLUSIONS: Hyperthermia as an adjunct to intravesical treatment would improve drug solubility, and likely drug delivery as some current regimens are insoluble without heat. Improvements in solubility also allow for testing of alternative administration regimens to improve drug delivery or tolerability. Further studies are needed to confirm that improvements in solubility result in increased drug delivery.

Intravesically instilled gemcitabine-induced lung injury in a patient with invasive urothelial carcinoma: A case report

BACKGROUND

Gemcitabine is a chemotherapy agent with relatively low toxicities, as a valid option for elderly patients with underlying diseases. Gemcitabine-induced pulmonary toxicities are rare and various, ranging from self-limited episodes of bronchospasm to fatal, progressive, severe, interstitial pneumonitis and respiratory failure. Intravesical gemcitabine instillations are commonly used to reduce recurrence or progression for non–muscle-invasive bladder cancer or urothelial cancer. Few severe toxicities have been reported for the intravesical instillation is assumed to be completely separated from the systemic circulation.

CASE SUMMARY

A 67-year-old patient received 30 cycles of intravesical gemcitabine instillation after transurethral resection and developed a 1-wk fever, cough, hemoptysis, and dyspnea. After a thorough checkup, bilateral consolidation and infiltration of the lungs were documented and a percutaneous lung biopsy confirmed organizing pneumonia after treatment with broad-spectrum empirical antibiotics failed. Tapered corticosteroids were administered, and pulmonary toxicity gradually resolved.

CONCLUSION

Gemcitabine-induced pulmonary toxicities present with various manifestations. In spite of the rare pulmonary involvement by the intravesical gemcitabine instillation, health care professionals who administer gemcitabine chemotherapy in this way should monitor for gemcitabine-induced pulmonary toxicities, particularly in patients with high-risk factors.

Novel anticancer therapy in BCG unresponsive non-muscle-invasive bladder cancer

INTRODUCTION

Many patients with non-muscle-invasive bladder cancer (NMIBC) failed intravesical BCG therapy. Currently, radical cystectomy is the recommended standard of care for those patients. There is unfortunately no effective other second-line therapy recommended.

AREAS COVERED

In this review, we present the topics of BCG unresponsive NMIBC; definition, prognosis, and further treatment options: immunotherapy, intravesical chemotherapy, gene therapy, and targeted individualized therapy.

EXPERT OPINION

There are major challenges of the management of NMIBC who failed BCG therapy as many patients refuse or are unfit for radical cystectomy. Multiple new modalities currently under investigation in ongoing clinical trials to better treat this category of patients. Immunotherapy, especially PD-1/PD-L1 inhibitors, offers exciting and potentially effective strategies for the treatment of BCG unresponsive NMIBC. As the data expands, it is sure that soon there will be established new guidelines for NMIBC.

Systematic Review of the Therapeutic Efficacy of Bladder-preserving Treatments for Non-muscle-invasive Bladder Cancer Following Intravesical Bacillus Calmette-Guérin

CONTEXT

There is a critical need for effective bladder-sparing therapies for bacillus Calmette-Guérin (BCG)-unresponsive non-muscle-invasive bladder cancer (NMIBC). Owing to the current lack of effective agents that can be used as a control, the US Food and Drug Administration began to accept single-arm trials for patients with carcinoma in situ (CIS), using complete response rate (CRR) and duration of response as the primary endpoints to support marketing applications. Despite the ensuing growth of clinical trials in this space, no consensus exists on a clinically relevant benchmark for CRR.

OBJECTIVE

To elucidate the CRR and recurrence-free rate (RFR) using bladder-sparing agents after BCG failure in order to provide a frame of reference for future clinical trial results.

EVIDENCE ACQUISITION

We performed a systematic review of clinical trials utilizing bladder-sparing therapeutics for NMIBC recurring after intravesical BCG (PROSPERO CRD42019130553). The search was performed in MEDLINE, EMBASE, and Cochrane Library. Relevant studies identified from bibliography search and conference abstracts were searched to complement the systematic review. A total of 42 studies utilizing 24 treatment options and consisting of 2254 patients were included for final analysis.

EVIDENCE SYNTHESIS

Median CRRs in the treatment of CIS-containing tumors were 26% at 6 mo, 17% at 12 mo, and 8% at 24 mo after treatment. In comparison, median RFRs in the papillary-only studies were 67% at 6 mo, 44% at 12 mo, and 10% at 24 mo. Specifically in the BCG-unresponsive population, 6- and 12-mo CRRs in CIS-containing patients treated with Mycobacterium phlei cell wall-nucleic acid complex were 45% and 27%, respectively, and the median 6-, 12-, and 24-mo disease-free rates in the other studies were 43%, 35%, and 18%, respectively. The median progression-free rate was 91%: 95% in the CIS-containing studies and 89% in studies restricted to papillary-only recurrences. Toxicities of intravesical agents were generally mild, with very few dose limiting toxicities.

CONCLUSIONS

We demonstrate that, to date, bladder-sparing therapies achieved modest efficacy in patients with NMIBC after BCG. Results from the current study will serve as a frame of reference for emerging trial results in the BCG-unresponsive space.

PATIENT SUMMARY

In this study, we found that bladder-sparing therapies achieved modest efficacy in patients with non-muscle-invasive bladder cancer after bacillus Calmette-Guérin (BCG). These results will serve to inform future clinical trial results for salvage agents used to treat BCG-unresponsive bladder cancer.

Optimizing pharmacokinetics of intravesical chemotherapy for bladder cancer

Non-muscle-invasive bladder cancer (NMIBC) remains one of the most common malignancies and is associated with considerable treatment costs. Patients with intermediate-risk or high-risk disease can be treated with intravesical BCG, but many of these patients will experience tumour recurrence, despite adequate treatment. Standard of care in these patients is radical cystectomy with urinary diversion, but this approach is associated with considerable morbidity and lifestyle modification. As an alternative, perioperative intravesical chemotherapy is recommended for low-risk papillary NMIBC, and induction intravesical chemotherapy is an option for patients with intermediate-risk NMIBC and BCG-unresponsive NMIBC. However, poor pharmaceutical absorption and drug washout during normal voiding can limit sustained drug concentrations in the urothelium, which reduces efficacy, and small-molecule chemotherapeutic agents can be absorbed through the urothelium into the bloodstream, leading to systemic adverse effects. Several novel drug delivery methods - including hyperthermia, mechanical sustained released devices and nanoparticle drug conjugation - have been developed to overcome these limitations. These novel methods have the potential to be combined with established chemotherapeutic agents to change the paradigm of NMIBC treatment.

Current advances in BCG-unresponsive non-muscle invasive bladder cancer

Introduction: The current first line therapy for high grade (HG) non-muscle invasive bladder cancer (NMIBC) is intravesical Bacillus Calmette-Guerin (BCG). Patients who recur or progress despite BCG are recommended to undergo radical cystectomy or participate in clinical trials. There is an urgent need for alternative therapies in the BCG-unresponsive NMIBC realm. Areas covered: We queried clinicaltrials.gov and pubmed.gov for current and recently completed early clinical trials pertaining to investigational agents used for the treatment of BCG-unresponsive NMIBC. These included intravesical chemotherapy, immunotherapy, vaccines, gene therapy, viruses, and agents used with novel drug delivery methods. In this article, we discuss the treatment guidelines for non-muscle invasive bladder cancer and therapeutic approaches under investigation in clinical trials. Expert opinion: The FDA is currently allowing single-arm studies as a pathway for approval in BCG-refractory patients with CIS. Although many agents are currently undergoing testing, none have been approved since Valrubicin. Hopefully, we will identify therapies sufficiently effective and durable to achieve FDA approval. Other considerations in this realm include the use of biomarkers in NMIBC to identify patients who will most likely respond to specific interventions. In addition, as systemic agents such as checkpoint inhibitors, are studied further, a multidisciplinary approach may be needed to treat this subset of patients.

Inhibition of urothelial carcinoma through targeted type I interferon-mediated immune activation

Type I interferon (IFN-I) has potent anti-tumor effects against urothelial carcinoma (UC) and may be an alternative treatment option for patients who do not respond to Bacillus Calmette-Guerin. However, the mechanisms that mediate the IFN-I-stimulated immune responses against UC have yet to be elucidated. Herein, we evaluated the anti-tumor mechanisms of IFN-I in UC in human patients and in mice. Patient tumors from a Phase I clinical trial with adenoviral interferon-α (Ad-IFNα/Syn3) showed increased expression of T cell and checkpoint markers following treatment with Ad-IFNα/Syn3 by RNAseq and immunohistochemistry analysis in 25% of patients. In mice, peritumoral injections of poly(I:C) into MB49 UC tumors was used to incite an IFN-driven inflammatory response that significantly inhibited tumor growth. IFN-I engaged both innate and adaptive cells, seen in increased intratumoral CD8 T cells, NK cells, and CD11b+Ly6G+ cells, but tumor inhibition was not reliant on any one immune cell type. Nonetheless, poly(I:C)-mediated tumor regression and change in the myeloid cell landscape was dependent on IL-6. Mice were also treated with poly(I:C) in combination with anti-PD-1 monoclonal antibody (mAb) to assess for additional benefit to tumor growth and animal survival. When used in combination with anti-PD-1 mAb, IFN-I stimulation prolonged survival, coinciding with inhibition of angiogenesis and enriched gene signatures of metabolism, extracellular matrix organization, and MAPK/AKT signaling. Altogether, these findings suggest IFN-I's immune-driven antitumor response in UC is mediated by IL-6 and a collaboration of immune cells, and its use in combination with checkpoint blockade therapy can increase clinical benefit.

Definitions, End Points, and Clinical Trial Designs for Non-Muscle-Invasive Bladder Cancer: Recommendations From the International Bladder Cancer Group

PURPOSE

To provide recommendations on appropriate clinical trial designs in non-muscle-invasive bladder cancer (NMIBC) based on current literature and expert consensus of the International Bladder Cancer Group.

METHODS

We reviewed published trials, guidelines, meta-analyses, and reviews and provided recommendations on eligibility criteria, baseline evaluations, end points, study designs, comparators, clinically meaningful magnitude of effect, and sample size.

RESULTS

NMIBC trials must be designed to provide the most clinically relevant data for the specific risk category of interest (low, intermediate, or high). Specific eligibility criteria and baseline evaluations depend on the risk category being studied. For the population of patients for whom bacillus Calmette-Guérin (BCG) has failed, the type of failure (BCG unresponsive, refractory, relapsing, or intolerant) should be clearly defined to make comparisons across trials feasible. Single-arm designs may be relevant for the BCG-unresponsive population. Here, a clinically meaningful initial complete response rate (for carcinoma in situ) or recurrence-free rate (for papillary tumors) of at least 50% at 6 months, 30% at 12 months, and 25% at 18 months is recommended. For other risk levels, randomized superiority trial designs are recommended; noninferiority trials are to be used sparingly given the large sample size required. Placebo control is considered unethical for all intermediate- and high-risk strata; therefore, control arms should comprise the current guideline-recommended standard of care for the respective risk level. In general, trials should use time to recurrence or recurrence-free survival as the primary end point and time to progression, toxicity, disease-specific survival, and overall survival as potential secondary end points. Realistic efficacy thresholds should be set to ensure that novel therapies receive due review by regulatory bodies.

CONCLUSION

The International Bladder Cancer Group has developed formal recommendations regarding definitions, end points, and clinical trial designs for NMIBC to encourage uniformity among studies in this disease.

Intravesical and alternative bladder-preservation therapies in the management of non-muscle-invasive bladder cancer unresponsive to bacillus Calmette-Guérin

Intravesical Bacillus Calmette-Guérin (BCG) remains the standard of care in the treatment of bladder carcinoma in situ and as adjuvant therapy after thorough transurethral resection of high-grade non-muscle-invasive bladder cancer. Despite BCG therapy, in up to 40% of patients it would recur and 60% to 70% of those would fail repeat BCG induction be deemed BCG unresponsive. For such patients, cystectomy remains the preferred treatment option per the American Urological Association and European Association of Urology, though some patients would be medically unfit or refuse radical surgery. Further intravesical therapy for bladder-preservation therapies may preserve quality of life in these patients and in some cases can be curative. There are numerous non-BCG intravesical salvage options available, including immunotherapy, single-agent chemotherapy, combination chemotherapy, and device-assisted chemotherapy. In addition, investigation of radiation-based treatment and other novel therapies including checkpoint inhibitors (programmed death-1/programmed death ligand-1), are currently underway. In this review, we examine the current status of alternatives to BCG in salvage therapy for bladder preservation.

Treatment options in non-muscle-invasive bladder cancer after BCG failure

Bladder cancer is the ninth-most prevalent cancer worldwide. Most patients with urothelial cell carcinoma of the bladder present with non-muscle-invasive disease and are treated with bacillus Calmette-Guérin (BCG) intravesical therapy. Many of these patients experience disease recurrence after BCG failure. Radical cystectomy is the recommended treatment for high-risk patients failing BCG. However, many patients are unfit for or unwilling to undergo this procedure. We searched the published literature on the treatment of non-muscle-invasive bladder cancer (NMIBC) after BCG failure. We review current evidence regarding intravesical therapy with gemcitabine, mitomycin combined with thermo-chemotherapy, docetaxel, nab-paclitaxel, photodynamic therapy (PDT), BCG with interferon (IFN), and combination sequentially administered chemotherapy.

Intravesical gemcitabine in combination with mitomycin C as salvage treatment in recurrent non-muscle-invasive bladder cancer

OBJECTIVES

To evaluate oncological outcomes after combination intravesical therapy with gemcitabine (GC) and mitomycin C (MMC) in the setting of recurrent non-muscle-invasive bladder cancer (NMIBC) after failure of previous intravesical therapy.

PATIENTS AND METHODS

We retrospectively identified patients with recurrent NMIBC after previous intravesical therapy, who refused or were not candidates for cystectomy, between 2005 and 2011. GC and MMC were sequentially instilled weekly for 6-8 weeks. Data were collected regarding patient demographics, bladder cancer history, and number and type of intravesical therapies before GC/MMC. Outcomes evaluated included time to recurrence and/or progression after GC/MMC. Recurrence-free outcomes were estimated using the Kaplan-Meier method, and Cox proportional hazards regression models were used to test the association of clinicopathological features with outcomes.

RESULTS

In all, 27 patients were identified, 23 with high-risk disease (high-grade or carcinoma in situ) and four with intermediate-risk disease (multifocal or recurrent low-grade). All patients received prior intravesical therapy, and 17 patients (63%) received multiple courses. Twenty-four patients were treated with BCG. The median (range) disease-free survival of all patients was 15.2 (1.7-39.3) months. Seventeen patients (63%) developed recurrent bladder cancer, a median of 15.2 months after therapy. One patient progressed to muscle-invasive disease 5 months after treatment, and one developed metastatic disease 22 months after treatment. Three patients went on to cystectomy. Ten patients (37%) had no evidence of disease at last follow-up, with a median follow-up of 22.1 months.

CONCLUSION

The combination of intravesical GC and MMC could offer durable recurrence-free survival to some patients with recurrent NMIBC who are not candidates for, or refuse, cystectomy.

Intravesical dual PI3K/mTOR complex 1/2 inhibitor NVP-BEZ235 therapy in an orthotopic bladder cancer model

NVP-BEZ235 is an inhibitor of both phosphatidylinositol 3-kinase (PI3K) and mammalian target of rapamycin complex 1/2 (mTORC1/2), and its antitumor activity is expected to be higher than that of mTORC1 inhibitors because it inhibits the upregulation of pAkt through mTORC2. We examined the efficacy of intravesical NVP-BEZ235 therapy in the treatment of bladder cancer using an orthotopic bladder cancer model. The cytotoxic effects of various concentrations of NVP-BEZ235 in MBT-2 cells were examined using a WST assay. The expression of pAkt, pS6 and p4EBP1 was evaluated in MBT-2 cells treated with NVP-BEZ235 using western blotting. Orthotopic models were established by implanting MBT-2 cells into the bladders of female C3H/He mice. We assigned C3H/He mice to 2 groups: a control group treated with vehicle control (n=15), and a group intravesically administered 40 µM (18.78 mg/l) of NVP-BEZ235 (n=15). NVP-BEZ235 inhibited the viability of MBT-2 cells in a dose-dependent manner. Furthermore, the expression of pAkt, pS6, and p4EBP1 was inhibited in NVP-BEZ235-treated MBT-2 cells. Bladder weights were significantly lower in the NVP-BEZ235-treated group than in the control group (P<0.05). An analysis of the tumor tissues revealed that the NVP-BEZ235 treatment strongly reduced pAkt, pS6 and p4EBP1 levels. An immunohistochemical analysis showed that NVP-BEZ235 significantly inhibited the expression of pS6. Intravesically administered NVP-BEZ235 exerted significant antitumor effects in the orthotopic bladder cancer model by inhibiting the PI3K/Akt/mTOR pathway. The intravesical instillation of a dual PI3K/mTORC1/2 inhibitor may represent a novel therapy for the treatment of bladder cancer.

New agents for bacillus Calmette-Guérin-refractory nonmuscle invasive bladder cancer

PURPOSE OF REVIEW

Radical cystectomy is the standard of care for patients who fail intravesical bacillus Calmette-Guérin (BCG) for nonmuscle invasive bladder cancer (NMIBC). For patients unwilling or unable to undergo cystectomy, numerous local therapies exist, although few are approved by the Food and Drug Administration. This review describes available therapies for this challenging clinical entity.

RECENT FINDINGS

Combination intravesical chemotherapy, targeted therapy, and drug delivery enhancement have all been under recent investigation and are promising, although none has proven superior as of yet.

SUMMARY

While BCG is standard treatment for intermediate and high-risk NMIBC, many patients fail therapy with recurrence or progression. Early cystectomy is the standard of care for BCG failure; however, many patients are unwilling or unable to undergo cystectomy. Multiple intravesical therapies have been used in this BCG failure population with moderate success, and, recently, technologies to improve drug delivery or create novel drugs have also been applied. Comparing efficacy of these therapies remain challenging as study cohorts are heterogeneous and study designs are variable. However, there are an increasing number of novel treatment options that can be offered to patients faced with recurrent NMIBC after BCG who seek bladder-sparing therapy.

Sequential intravesical mitomycin plus Bacillus Calmette-Guérin for non-muscle-invasive urothelial bladder carcinoma: translational and phase I clinical trial

PURPOSE

To determine the safety and toxicities of sequential MMC (mitomycin C) + BCG (bacillus Calmette-Guérin) in patients with non-muscle-invasive bladder cancer (NMIBC) and explore evidence for potentiation of BCG activity by MMC.

EXPERIMENTAL DESIGN

A 3 + 3 phase I dose-escalation trial of six weekly treatments was conducted in patients with NMIBC. MMC (10, 20, or 40 mg) was instilled intravesically for 30 minutes, followed by a 10-minute washout with gentle saline irrigation and then instillation of BCG (half or full strength) for 2 hours. Urine cytokines were monitored and compared with levels in a control cohort receiving BCG only. Murine experiments were carried out as described previously.

RESULTS

Twelve patients completed therapy, including 3 patients receiving full doses. The regimen was well tolerated with no treatment-related dose-limiting toxicities. Urinary frequency and urgency, and fatigue were common. Eleven (91.7%) patients were free of disease at a mean (range) follow-up of 21.4 (8.4-27.0) months. Median posttreatment urine concentrations of IL2, IL8, IL10, and TNFα increased over the 6-week treatment period. A greater increase in posttreatment urinary IL8 during the 6-week period was observed in patients receiving MMC + BCG compared with patients receiving BCG monotherapy. In mice, intravesical MMC + BCG skewed tumor-associated macrophages (TAM) toward a beneficial M1 phenotype.

CONCLUSIONS

Instillation of sequential MMC + BCG is safe tolerable up to 40-mg MMC plus full-strength BCG. This approach could provide improved antitumor activity over BCG monotherapy by augmenting beneficial M1 TAMs.

Combined bacillus Calmette–Guerin and interferon use in superficial bladder cancer

Due to its high rate of local recurrence after transurethral surgery, superficial bladder cancer is often treated with adjuvant topical intravesical chemotherapy or biological agents, such as bacillus Calmette-Guerin or interferon-alpha. Recent laboratory testing has revealed that combination interferon-alpha with bacillus Calmette-Guerin results in remarkable synergy, affecting not only bladder tumors directly but also enhancing the immune response to bacillus Calmette-Guerin by orders of magnitude. Clinical studies are now demonstrating lower toxicity with combination low-dose bacillus Calmette-Guerin/interferon regimens, while providing a much needed salvage option for previous bacillus Calmette-Guerin failures.

Superficial bladder cancer: part 2. Management

In the second section of a two-part article, the recent literature is reviewed and the management of nonmuscle-invasive transitional cell carcinoma of the bladder is discussed. Particular attention is given to the indications and timing of intravesical chemotherapy and immunotherapy and the differences in efficacy and side-effect profiles of the available agents. The indications and role of second-look transurethral resection are reviewed. Additionally, the role of bacillus Calmette-Guerin in the management of this disease in terms of definitive treatment and maintenance therapy is discussed. We also offer a review of the literature regarding therapies for bacillus Calmette-Guerin-refractory nonmuscle-invasive transitional cell carcinoma of the bladder and their current place in practice.

SWOG S0353: Phase II trial of intravesical gemcitabine in patients with nonmuscle invasive bladder cancer and recurrence after 2 prior courses of intravesical bacillus Calmette-Guérin

PURPOSE

Prior phase II studies of intravesical gemcitabine have shown it to be active and well tolerated, but durable responses in patients with nonmuscle invasive bladder cancer who have experienced recurrence after bacillus Calmette-Guérin treatment are uncommon. We performed a multi-institutional phase II study within the SWOG (Southwest Oncology Group) cooperative group to evaluate the potential role of gemcitabine induction plus maintenance therapy in this setting.

MATERIALS AND METHODS

Eligible patients had recurrent nonmuscle invasive bladder cancer, stage Tis (carcinoma in situ), T1, Ta high grade or multifocal Ta low grade after at least 2 prior courses of bacillus Calmette-Guérin. Patients were treated with 2 gm gemcitabine in 100 cc normal saline intravesically weekly × 6 and then monthly to 12 months. Cystoscopy and cytology were performed every 3 months, with biopsy at 3 months and then as clinically indicated. Initial complete response was defined as negative cystoscopy, cytology and biopsy at 3 months.

RESULTS

A total of 58 patients were enrolled in the study and 47 were evaluable for response. Median patient age was 70 years (range 50 to 88). Of the evaluable patients 42 (89%) had high risk disease, including high grade Ta in 12 (26%), high grade T1 in 2 (4%) and carcinoma in situ in 28 (60%) with or without papillary lesions. At the initial 3-month evaluation 47% of patients were free of disease. At 1 year disease had not recurred in 28% of the 47 patients, all except 2 from the high risk group, and at 2 years disease had not recurred in 21%.

CONCLUSIONS

Intravesical gemcitabine has activity in high risk nonmuscle invasive bladder cancer and offers an option for patients with recurrence after bacillus Calmette-Guérin who are not suitable for cystectomy. However, less than 30% of patients had a durable response at 12 months even with maintenance therapy.

Phase I trial of intravesical recombinant adenovirus mediated interferon-α2b formulated in Syn3 for Bacillus Calmette-Guérin failures in nonmuscle invasive bladder cancer

PURPOSE

A phase I trial of intravesical recombinant adenovirus mediated interferon-α2b gene therapy (rAd-IFNα) formulated with the excipient SCH Syn3 was conducted in patients with nonmuscle invasive bladder cancer who had disease recurrence after treatment with bacillus Calmette-Guérin. The primary objective was to determine the safety of rAd-IFNα/Syn3. Secondary end points were demonstrated effective rAd-IFNα gene expression and preliminary evidence of clinical activity at 3 months.

MATERIALS AND METHODS

A total of 17 patients with recurrent nonmuscle invasive bladder cancer after bacillus Calmette-Guérin treatment were enrolled in the study. A single treatment of rAd-IFNα (3 × 10(9) to 3 × 10(11) particles per ml) formulated with the excipient Syn3 was administered. Patient safety was evaluated for 12 or more weeks. Efficacy of gene transfer was determined by urine IFNα protein concentrations. Preliminary drug efficacy was determined at 3 months.

RESULTS

Intravesical rAd-IFNα/Syn3 was well tolerated as no dose limiting toxicity was encountered. Urgency was the most common adverse event and all cases were grade 1 or 2. rAd-IFNα DNA was not detected in the blood. However, transient low serum IFNα and Syn3 levels were measured. High and prolonged dose related urine IFNα levels were achieved with the initial treatment. Of the 14 patients treated at doses of 10(10) or more particles per ml with detectable urine IFNα, 6 (43%) experienced a complete response at 3 months and 2 remained disease-free at 29.0 and 39.2 months, respectively.

CONCLUSIONS

Intravesical rAd-IFNα/Syn3 was well tolerated with no dose limiting toxicity encountered. Dose dependent urinary IFNα concentrations confirmed efficient gene transfer and expression. Intravesical rAd-IFNα/Syn3 demonstrated clinical activity in nonmuscle invasive bladder cancer recurring after bacillus Calmette-Guérin.

Experience with newer intravesical chemotherapy for high-risk non-muscle-invasive bladder cancer

The definitive treatment for patients with high-risk non-muscle-invasive bladder cancer (NMIBC) who fail to respond to intravesical bacillus Calmette-Guérin (BCG) is cystectomy. However, many patients who experience recurrence after BCG are either poor operative candidates or refuse surgery due to the long-term impact on their quality of life. In the last decade, there has been an increased interest in alternative intravesical therapies, and several novel chemotherapeutics have emerged as promising agents for high-risk NMIBC patients unable or unwilling to undergo cystectomy. Additionally, extended treatment regimens with combined induction and maintenance therapy have been investigated, and may increase the durability of response to these new agents, as has been shown for conventional intravesical therapy.

Intravesical therapy for urothelial carcinoma of the bladder

Transurethral resection is an effective therapy for non-muscle-invasive bladder cancer. However, the high rates of recurrence and significant risk of progression in higher grade tumors mandates additional therapy with intravesical agents. In this review we discuss the role of various intravesical agents currently in use including the immunomodualtory agent BCG and chemotherapeutic agents. We discuss the current guidelines and the role of these therapeutic agents in the context of higher grade Ta and T1 tumors.

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

Objective:

To reduce adverse effects and improve efficacy of intravesical BCG for bladder cancer, alternative treatment options were investigated in an orthotopic rat tumor model.

Methods:

Superficial bladder cancer was established in syngeneic female rat bladders by instillation of AY-27 cells. Animals were randomly assigned to treatment groups including dose escalation of intravesical BCG with or without interferon-α (IFN-α) or interleukin-2 (IL-2); or graded doses of gemcitabine alone; or BCG plus gemcitabine. Treatments were given twice weekly for 3 weeks. Rats in control groups received saline instillations. Treatment response was monitored by animals’ well-being, survival days, tumor growth inhibition, and histological examination at necropsy.

Results:

Rats receiving monotherapy with intravesical BCG, gemcitabine, or IFN-α, attained significantly better survival and tumor reduction compared with control (P = 0.002; 0.001; 0.002, respectively, Log-rank Test). A dose-dependent treatment response was observed in animals with established bladder tumor receiving escalated BCG instillations. Only high-dose BCG significantly improved animal survival. Although high-dose BCG plus gemcitabine or IFN-α did not increase benefit over monotherapies, low-dose BCG plus IL-2 did show improved efficacy (P = 0.01).

Conclusion:

Intravesical monotherapies with gemcitabine and IFN-α were as effective as BCG for treatment of early non-muscle-invasive urothelial bladder cancer in this immune competent rat model. Combining these agents with high-dose BCG did not further increase efficacy. However, combining low-dose BCG with IL-2 enhanced BCG effectiveness.

Update on the management of non-muscle invasive bladder cancer

Non-muscle invasive bladder cancer (NMIBC) is a heterogeneous population of tumours accounting for 80% of bladder cancers. Over the years, the management of this disease has been changing with improvements in results and outcomes. In this review, we focus on the latest updates on the management of NMIBC.

The management of BCG failure in non-muscle-invasive bladder cancer: an update

Up to 40% of patients with non-muscle-invasive bladder cancer (NMIBC) will fail intravesical bacillus Calmette-Guérin (BCG) therapy. There is unfortunately no current gold standard for salvage intravesical therapy after appropriate BCG treatment. Indeed, outcomes are at best suboptimal. The vast majority of low-grade NMIBC are prone to recur but very rarely progress. Failure after intravesical BCG in these patients is usually superficial and low-grade. At the other end of the spectrum, failure to respond to BCG in high-risk T1 bladder cancer and/or carcinoma in situ (CIS or TIS) is more problematic, since those tumours often have the potential to progress to muscle invasion. In these cases, radical cystectomy remains the mainstay after BCG failure. With appropriate selection, certain patients who "fail" BCG (but with favourable risk factors) can be managed with intravesical regimens, including repeated BCG, BCG plus cytokines, intravesical chemotherapy, thermochemotherapy or new immunotherapeutic modalities. In this review, reasons explaining BCG failure, how to define BCG failure, optimal risk stratification and prediction of response and management of BCG failures are discussed.

Contemporary management of patients with high-risk non-muscle-invasive bladder cancer who fail intravesical BCG therapy

It is advocated that patients with high-risk non-muscle-invasive bladder cancer (NMIBC) receive an adjuvant course of intravesical Bacille Calmette-Guerin (BCG) as first-line treatment. However, a substantial proportion of patients will 'fail' BCG, either early with persistent (refractory) disease or recur late after a long disease-free interval (relapsing). Guideline recommendation in the 'refractory' setting is radical cystectomy, but there are situations when extirpative surgery is not feasible due to competing co-morbidity, a patient's desire for bladder preservation or reluctance to undergo surgery. In this review, we discuss the contemporary management of NMIBC in patients who have failed prior BCG and are not suitable for radical surgery and highlight the potential options available. These options can be categorised as immunotherapy, chemotherapy, device-assisted therapy and combination therapy. However, the current data are still inadequate to formulate definitive recommendations, and data from ongoing trials and maturing studies will give us an insight into whether there is a realistic efficacious second-line treatment for patients who fail intravesical BCG but are not candidates for definitive surgery.

Enhanced antitumor effect of coincident intravesical gemcitabine plus BCG therapy in an orthotopic bladder cancer model

OBJECTIVES

To evaluate the antitumor effect of the coincident administration of intravesical gemcitabine (Gem) plus bacillus Calmette-Guérin (BCG) in an orthotopic bladder cancer model.

METHODS

We evaluated the cytotoxic effect of gemcitabine against MBT-2 cells in vitro. Orthotopic tumors were established by implanting MBT-2 cells into the bladder of syngeneic female C3H mice. Intravesical Gem administration was evaluated at various doses: 0 mg (control); 1, 2, 4, and 8 mg (n = 8 for each group). Next, a comparative evaluation of tumor growth among the control, Gem-alone, BCG-alone, and combined Gem + BCG groups was performed (n = 16 for each group). Therapy was administered at 3-day intervals starting on day 5 and repeated 6 times. To evaluate the proliferative activity among the groups, Ki-67 immunostaining of the tumor was performed.

RESULTS

Gemcitabine exhibited a dose-dependent antitumor effect. Of the 8 mice in each group treated with a dose of 0, 1, 2, 4, or 8 mg of Gem, 1, 4, 4, 4, 5, and 4 mice failed to develop tumors and survived, respectively. The combination of Gem + BCG (54.1 ± 9.4 days) provided a significant survival advantage compared with BCG-alone (39.0 ± 16.4 days) (P = .02). Ki-67 expression, representing tumor proliferation, was significantly lower in the combined Gem + BCG group than in the BCG-alone group (P < .01).

CONCLUSIONS

Our results suggest that intravesical Gem + BCG treatment induces an enhanced antitumor effect against bladder tumors.

Update on intravesical agents for non-muscle-invasive bladder cancer

Major controversies still exist with regard to the indication, type and regimen of intravesical therapy for non-muscle-invasive bladder cancer. Other areas of controversy are the criteria for response/failure of treatment and for decisions regarding secondary intravesical therapy versus radical cystectomy. In this article, we analyze the different intravesical therapeutic strategies and compare their safety and efficacy. Well-designed clinical trials have found that the addition of bacillus Calmette-Guerin (BCG) to transurethral resection (TUR) decreases the risk for both disease recurrence and progression. These encouraging results are sustained even in patients with recurrent or aggressive disease, including patients whose prior intravesical chemotherapy has failed. Most investigators believe that the efficacy of BCG therapy can be maximized with maintenance therapy. Mitomycin C (MMC), the most commonly used intravesical chemotherapy to date, decreases the risk of disease recurrence but not disease progression when used after TUR compared with TUR alone. The oncologic efficacy of intravesical MMC can be optimized by increasing its concentration in addition to alkalinizing and reducing urine production. For patients at high risk of disease progression, BCG with maintenance therapy should be the preferred primary intravesical therapeutic strategy. However, MMC can be considered as a viable alternative for patients with papillary tumors (no carcinoma in situ) that are at low or intermediate risk of disease progression. Combination intravesical therapy may be more successful than single-agent strategies. Intravesical therapy failures indicate the need to include radical cystectomy as an option in the management decision.

Novel intravesical therapies for non-muscle-invasive bladder cancer refractory to BCG

The definitive treatment for patients with non-muscle-invasive bladder cancer (NMIBC) who fail to respond to intravesical BCG is cystectomy. When a patient is deemed BCG-refractory and cannot or will not undergo cystectomy, alternative intravesical therapy may be the most effective way to minimize recurrence and progression. A number of immunotherapeutic and chemotherapeutic agents have been given intravesically over the years, and several recently and currently investigated novel agents appear to be particularly promising for the management of BCG-refractory NMIBC. The most effective treatments in the future will likely utilize targeted therapies based on the underlying genetic mutations associated with each individual diagnosis of NMIBC.

Investigational therapies for non-muscle invasive bladder cancer

IMPORTANCE OF THE FIELD

Bacillus Calmette-Guérin (BCG) is currently the most effective adjuvant intravesical agent at preventing disease recurrence and the only therapy shown to inhibit disease progression in non-muscle invasive bladder cancer (NMIBC). However, recurrence rates as high as 30% and significant local/systemic toxicity have resulted in an increased interest in the use of alternative intravesical agents.

AREAS COVERED IN THE REVIEW

Our aim is to discuss recent clinical trial evidence utilizing novel intravesical agents for treatment of NMIBC. A systematic literature review was performed via the National Center for Biotechnology Information databases to identify pertinent studies from 2000-2009.

WHAT THE READER WILL GAIN

A durable response has been demonstrated with alternative agents in patients refractory to or intolerant of BCG. This review compares the merits and shortcomings of these emerging agents, focusing on clinical trial safety and efficacy results.

TAKE HOME MESSAGE

Despite recent enthusiasm for novel agents, radical cystectomy remains the treatment of choice for patients with NMIBC who have failed intravesical therapy. However, evidence is accumulating that novel agents provide an efficacious alternative in patients refractory or intolerable to BCG or unfit for cystectomy. Further randomized prospective data are required to demonstrate a recurrence- and progression-free benefit compared with BCG.