The novel use of intravesical docetaxel for the treatment of non-muscle invasive bladder cancer refractory to BCG therapy: a single institution experience

New Intravesical Agents for BCG-Unresponsive High-Risk Non-Muscle Invasive Bladder Cancer

BACKGROUND

With the exception of the FDA-approved valrubicin and pembrolizumab, there are no standard second-line treaments for BCG-unresponsive high-risk non-muscle invasive bladder cancer (NMIBC).

OBJECTIVES

To provide a systematic review of the novel intravesically administered therapeutic agents for the salvage treatment of BCG-unresponsive NMIBC.

METHODS

Online search of the PubMed, EMBASE and Web of Science databases was performed. The endpoints of this review were to evaluate the efficacy of the agents in terms of complete response rates (CR) and durability of CR, overall survival, recurrence-free survival and cancer-specific survival and to report on their toxicity profile. A search on Clinicaltrials.gov was performed to identify ongoing clinical trials.

RESULTS

14 studies were included in this review. The critical clinical need for the development of an effective, safe and durable intravesical drug for the salvage treatment of high-risk NMIBC seems to be met mainly by intravesical gene therapy; in fact, data support the FDA-approved nadofaragene firadenovec as a potentially important therapeutic advancement in this context. Promising results are also being obtained by the combination of N-803/BCG and by innovative drug delivery systems.

CONCLUSIONS

Considering the plethora of novel intravesical treatments that have completed phase II evaluation, one can reasonably expect that clinicians will soon have at their disposal new agents and treatment options for BCG-unresponsive NMIBC. In the near future, it will be up to the urologist to identify, for each specific patient, the right agent to use, based on safety, results and cost-effectiveness.

Glabridin inhibits urothelial bladder carcinoma cell growth in vitro and in vivo by inducing cell apoptosis and cell cycle arrest

Glabridin (GLA) has a variety of biological activities and therapeutic effects in cancers. Whereas the effect of GLA on urothelial bladder carcinoma (UBC) cells and its underlying mechanisms remain unknown. The study revealed the effect of GLA on UBC and the potential mechanism of inducing cell apoptosis in vivo and in vitro. After treated with different concentrations of GLA, the cell activity decreased in a time- and dose-dependent manner. The IC₅₀ values of BIU-87 and EJ cells at 48 h were 6.02 μg/ml (18.6 μm) and 4.36 μg/ml (13.4 μm), respectively. Additionally, GLA-induced apoptosis and cycle arrest of BIU-87 and EJ cells in G2 phase. Furthermore, wound healing experiments showed that GLA significantly reduced the migration activities of BIU-87 and EJ cells. Mechanically, GLA obviously increased the expression of BIM, BAK1, and CYCS in both mRNA and protein levels, which led to the activation of the endogenous apoptotic pathway. Finally, GLA remarkably inhibited the growth of UBC tumors in vivo. In summary, GLA inhibited UBC cells growth in vitro and in vivo by inducing cell apoptosis and cell cycle arrest, highlighting that GLA could be utilized as a component to design a novel anti-UBC drug.

NCCN Guidelines® Insights: Bladder Cancer, Version 2.2022

The NCCN Guidelines for Bladder Cancer provide recommendations for the diagnosis, evaluation, treatment, and follow-up of patients with bladder cancer and other urinary tract cancers (upper tract tumors, urothelial carcinoma of the prostate, primary carcinoma of the urethra). These NCCN Guidelines Insights summarize the panel discussion behind recent important updates to the guidelines regarding the treatment of non-muscle-invasive bladder cancer, including how to treat in the event of a bacillus Calmette-Guérin (BCG) shortage; new roles for immune checkpoint inhibitors in non-muscle invasive, muscle-invasive, and metastatic bladder cancer; and the addition of antibody-drug conjugates for metastatic bladder cancer.

Emerging treatments for bacillus Calmette-Guérin-unresponsive non-muscle-invasive bladder cancer

Intravesical bacillus Calmette–Guérin (BCG) immunotherapy has been the gold standard adjuvant treatment for intermediate- and high-risk non-muscle-invasive bladder cancer (NMIBC) after transurethral resection of bladder tumor (TURBT). BCG immunotherapy prevents disease recurrence and progression to muscle-invasive disease following TURBT. Although most patients initially respond well to intravesical BCG, considerable concern has been raised for patients with BCG failure who are refractory or recur in 6 months after their last BCG, which implies ‘BCG-unresponsiveness’. Based on current clinical guidelines, early radical cystectomy (RC) is recommended to treat BCG-unresponsive NMIBC. However, due to the high risk of morbidity and mortality of RC and patients' desire to preserve their own bladder, there is a critical unmet need for alternative conservative treatments as bladder-sparing strategies in BCG-unresponsive patients. Trials for effective bladder-sparing treatments are ongoing, and several novel agents have been recently tested in the NMIBC setting. The goal of this review is to introduce and summarize recently reported novel and emerging drugs and ongoing clinical trials for BCG-unresponsive NMIBC.

BCG-unresponsive high-grade non-muscle invasive bladder cancer: what does the practicing urologist need to know?

Purpose

Bacille Calmette-Guérin (BCG) is a well-established treatment for preventing or delaying tumour recurrence following high-grade nonmuscle invasive bladder cancer (NMIBC) resection. However, many patients will experience recurrence or progression during or following BCG. This scenario has been one of the most challenging in urologic oncology for several decades since BCG implementation. Finally, significant progress has occurred lately. The aim of this review was to summarize for the practising urologist the current treatment options available in 2020 or expected to be ready for routine use in the near future for patients with high-risk NMIBC who experience BCG failure.

Methods

Narrative review using data through the end of 2020.

Results

First, the definition of BCG unresponsive disease which is critical in counseling and managing patients has finally reached a consensus. Second, some promising options other than radical cystectomy are finally available and many other should be in a near future. The options can be categorized as chemotherapy, device-assisted therapy, check-point inhibitors, new intravesical and systemic agents and sequential combinations of these newer modalities with conventional therapy.

Conclusions

Considering the options that are currently under scrutiny, many of which in phase III trials, clinicians should have at their disposal several new treatment options in the next five years.

Novel treatment of upper tract urothelial carcinoma in situ with docetaxel in BCG refractory patients

INTRODUCTION

Patients with upper-tract carcinoma in situ (UT-CIS) that have failed treatment with BCG are recommended for radical nephroureterectomy (RNU). We describe a cohort of patients with BCG-refractory UT-CIS that were treated with docetaxel, a novel agent in the approach to topical therapy.

METHODS

Patients with pathologically proven UT-CIS from 2012 to 2020 with an imperative indication for organ preservation and history of BCG-refractory disease were included. Each patient underwent ureteroscopy with biopsy and selective cytology pre- and postinduction, and after each maintenance course. Complete response (CR) was defined as the absence of visualized lesions on ureteroscopy, negative selective cytology, and absence of clinical progression. No response (NR) was defined as persistence of lesions after induction or absence of visualized lesions with persistently positive cytology.

RESULTS

Seven patients and 10 renal units were treated. Six of the 10 renal units had initial CR (60%). Three patients with NR went on to have RNU, one of which subsequently died due to cancer-specific mortality. One patient with bilateral disease had NR in 10 renal unit and cure in the other. This patient subsequently developed recurrence in his remaining renal unit. A second patient had CR in both kidneys for 6 years, but 1 year after finishing maintenance regimen developed HG disease in 1 ureter. Average follow-up was 33 months.

CONCLUSION

This study demonstrates efficacy of docetaxel as a treatment option for patients with UT-CIS with a contraindication to RNU after failing BCG. Response rates of 60% appear to be similar to those of BCG-refractory bladder CIS.

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.

Quality Indicators for Bladder Cancer Services: A Collaborative Review

CONTEXT

There is a lack of accepted consensus on what should constitute appropriate quality-of-care indicators for bladder cancer.

OBJECTIVE

To evaluate the optimal management of bladder cancer and propose quality indicators (QIs).

EVIDENCE ACQUISITION

A systematic review was performed to identify literature on current optimal management and potential quality indicators for both non-muscle-invasive (NMIBC) and muscle-invasive (MIBC) bladder cancer. A panel of experts was convened to select a recommended list of QIs.

EVIDENCE SYNTHESIS

For NMIBC, preoperative QIs include tobacco cessation counselling and appropriate imaging before initial transurethral resection of bladder tumour (TURBT). Intraoperative QIs include administration of antibiotics, proper safe conduct of TURBT using a checklist, and performing restaging TURBT with biopsy of the prostatic urethra in appropriate cases. Postoperative QIs include appropriate receipt of perioperative adjuvant therapy, risk-stratified surveillance, and appropriate decision to change therapy when indicated (eg, bacillus Calmette-Guerin [BCG] unresponsive). For MIBC, preoperative QIs include multidisciplinary care, selection for candidates for continent urinary diversion, receipt of neoadjuvant cisplatin-based chemotherapy, time to commencing radical treatment, consideration of trimodal therapy as a bladder-sparing alternative in select patients, preoperative counselling with stoma marking, surgical volume of radical cystectomy, and enhanced recovery after surgery protocols. Intraoperative QIs include adequacy of lymphadenectomy, blood loss, and operative time. Postoperative QIs include prospective standardised monitoring of morbidity and mortality, negative surgical margins for pT2 disease, appropriate surveillance after primary treatment, and adjuvant cisplatin-based chemotherapy in appropriate cases. Participation in clinical trials was highlighted as an important component indicating high quality of care.

CONCLUSIONS

We propose a set of QIs for both NMIBC and MIBC based on established clinical guidelines and the available literature. Although there is currently a lack of level 1 evidence for the benefit of implementing these QIs, we believe that the measurement of these QIs could aid in the improvement and benchmarking of optimal care for bladder cancer.

PATIENT SUMMARY

After a systematic review of existing guidelines and literature, a panel of experts has recommended a set of quality indicators that can help providers and patients measure and strive towards optimal outcomes for bladder cancer care.

Salvage Hyperthermic Gemcitabine and Docetaxel Combination Chemotherapy After BCG Failure in Non-Muscle Invasive Bladder Cancer Patients

BACKGROUND: Bacillus Calmette-Guerin (BCG) is the recommended therapy for high and intermediate risk non-muscle invasive bladder cancer (NMIBC), but treatment failure is common. While a radical cystectomy is recommended after BCG failure, some patients desire bladder preservation and others are poor surgical candidates. Salvage chemotherapy treatments may be offered to this subgroup of patients. OBJECTIVE: To assess if combination, hyperthermic Gemcitabine and Docetaxel chemotherapy (GEM/DOCE) is a safe and effective salvage option for treating NMIBC. METHODS: Sixty patients who received our GEM/DOCE protocol between 2007–2017 were identified (51 BCG failures, 9 BCG naïve). This study measured overall treatment success, defined as no recurrence, progression, cystectomy, nor death due to bladder cancer. Kaplan-Meier curves were used to ascertain probability of treatment success. The log-rank test was used to identify factors associated with treatment success. RESULTS: Sixty patients received treatment with a median follow-up of 14.9 months. All patients completed the induction course with no significant adverse effects. Overall treatment success was 83% at first surveillance, 69% at 1 year, and 55% at 2 years in the entire cohort, and 90% at first surveillance, 74% at 1 year, and 56% at 2 years in the BCG-failure patients. All-cause and bladder-cancer-specific survival were both 97.9% at 1 year, 85.9% and 94.6% respectively at 2 years. Three patients underwent cystectomy at a median of 10.2 months, two of these were secondary to recurrences. Three patients had progression of their disease. CONCLUSIONS: Hyperthermic GEM/DOCE seems to be a well-tolerated salvage regimen that demonstrates a reasonable efficacy and warrants further investigation.

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.

Alternative therapies in patients with non-muscle invasive bladder cancer

Bladder cancer (BC) is one of the leading causes of cancer-related deaths worldwide. Despite, the majority of the cases were diagnosed as non-muscle invasive bladder cancer (NMIBC) with favorable prognosis, it has tendency to recur or progress to a higher grade or stage. The first line treatment of patients with NMIBC is transurethral resection with adjuvant therapies primarily intravesical Bacillus Calmette-Guérin (BCG) immunotherapy. However, in a portion of patients whose BCG treatment failed, alternative treatments may be required. Furthermore, intravesical BCG may be contraindicated in or untolerated by a group of patients. For these patients, some treatment options are readily available and a variety of them are currently under clinical investigation. In this review, these alternative therapies have been summarized.

Intravesical rAd-IFNα/Syn3 for Patients With High-Grade, Bacillus Calmette-Guerin-Refractory or Relapsed Non-Muscle-Invasive Bladder Cancer: A Phase II Randomized Study

Purpose Many patients with high-risk non-muscle-invasive bladder cancer (NMIBC) are either refractory to bacillus Calmette-Guerin (BCG) treatment or may experience disease relapse. We assessed the efficacy and safety of recombinant adenovirus interferon alfa with Syn3 (rAd-IFNα/Syn3), a replication-deficient recombinant adenovirus gene transfer vector, for patients with high-grade (HG) BCG-refractory or relapsed NMIBC. Methods In this open-label, multicenter (n = 13), parallel-arm, phase II study ( ClinicalTrials.gov identifier: NCT01687244), 43 patients with HG BCG-refractory or relapsed NMIBC received intravesical rAd-IFNα/Syn3 (randomly assigned 1:1 to 1 × 10¹¹ viral particles (vp)/mL or 3 × 10¹¹ vp/mL). Patients who responded at months 3, 6, and 9 were retreated at months 4, 7, and 10. The primary end point was 12-month HG recurrence-free survival (RFS). All patients who received at least one dose were included in efficacy and safety analyses. Results Forty patients received rAd-IFNα/Syn3 (1 × 10¹¹ vp/mL, n = 21; 3 × 10¹¹ vp/mL, n = 19) between November 5, 2012, and April 8, 2015. Fourteen patients (35.0%; 90% CI, 22.6% to 49.2%) remained free of HG recurrence 12 months after initial treatment. Comparable 12-month HG RFS was noted for both doses. Of these 14 patients, two experienced recurrence at 21 and 28 months, respectively, after treatment initiation, and one died as a result of an upper tract tumor at 17 months without a recurrence. rAd-IFNα/Syn3 was well tolerated; no grade four or five adverse events (AEs) occurred, and no patient discontinued treatment because of an adverse event. The most frequently reported drug-related AEs were micturition urgency (n = 16; 40%), dysuria (n = 16; 40%), fatigue (n = 13; 32.5%), pollakiuria (n = 11; 28%), and hematuria and nocturia (n = 10 each; 25%). Conclusion rAd-IFNα/Syn3 was well tolerated. It demonstrated promising efficacy for patients with HG NMIBC after BCG therapy who were unable or unwilling to undergo radical cystectomy.

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.

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.

The Role of Interferon in the Management of BCG Refractory Nonmuscle Invasive Bladder Cancer

Background. Thirty to forty percent of patients with high grade nonmuscle invasive bladder cancer (NMIBC) fail to respond to intravesical therapy with bacillus Calmette-Guerin (BCG). Interferon-α2B plus BCG has been shown to be effective in a subset of patients with NMIBC BCG refractory disease. Here we present a contemporary series on the effectiveness and safety of intravesical BCG plus interferon-α2B therapy in patients with BCG refractory NMIBC. Methods. From January of 2005 to April of 2014 we retrospectively found 44 patients who underwent induction with combination IFN/BCG for the management of BCG refractory NMIBC. A chart review was performed to assess initial pathological stage/grade, pathological stage/grade at the time of induction, time to IFN/BCG failure, pathological stage/grade at failure, postfailure therapy, and current disease state. Results. Of the 44 patients who met criteria for the analysis. High risk disease was found in 88.6% of patients at induction. The 12-month and 24-month recurrence-free survival were 38.6% and 18.2%, respectively. 25 (56.8%) ultimately had disease recurrence. Radical cystectomy was performed in 16 (36.4%) patients. Conclusion. Combination BCG plus interferon-α2B remains a reasonably safe alternative treatment for select patients with BCG refractory disease prior to proceeding to radical cystectomy.

Mucoadhesive polyacrylamide nanogel as a potential hydrophobic drug carrier for intravesical bladder cancer therapy

In this paper, amine-functionalized polyacrylamide nanogels (PAm-NH2) loaded with docetaxel (DTX) were evaluated as a mucoadhesive and sustained intravesical drug delivery (IDD) system for potential bladder cancer therapy. Nanogels have not been applied for such therapy before. The mucoadhesiveness of the PAm-NH2 nanogels, which is a critical factor for IDD application, was investigated using the mucin-particle method and by analyzing the direct attachment of the PAm-NH2 nanogels onto the luminal surface of porcine urinary bladder. DTX, as a model hydrophobic drug, was successfully loaded into hydrophilic PAm-NH2 nanogels with high loading efficiency (>90%), and sustained release of DTX from the nanogels over 9 days in artificial urine was achieved. The nanogels were also taken in by bladder cancer cells in a concentration-dependent manner. The efficiency of the DTX-loaded nanogels in killing UMUC3 and T24 bladder cancer cells was determined to be equivalent to free DTX, and the morphology of the bladder urothelium was not adversely altered by the PAm-NH2 nanogels. These findings indicate that such mucoadhesive nanogels are potentially a promising candidate for intravesical delivery of hydrophobic drugs in bladder cancer therapy.

Construction of a recombinant-BCG containing the LMP2A and BZLF1 genes and its significance in the Epstein-Barr virus positive gastric carcinoma

The signal peptide Ag85B of Bacillus Chalmette-Guerin (BCG) was used to construct a recombinant plasmid of BCG. The BCG-Ag85B gene and fused EBV LMP2A and BZLF1 genes were amplified and successively inserted into the Escherichia coli-BCG shuttle-vector pMV261. The recombinant plasmids were then amplified in E. coli DH5α and transformed into competent BCG. The expression of BZLF1 and LMP2A fusion proteins in recombinant-BCG (rBCG) was shown by Western blot. After the injection of recombinant-BCG into mice, antibodies against the fusion protein BZLF1 and LMP2A were measured by ELISA, and the cellular immune effects were determined by the lactate dehydrogenate (LDH) release assays. The results confirmed that the cloned genes of BCG-Ag85B and Z2A were correctly inserted into the vector pMV261. The recombinant plasmid pMVZ2A expressed Z2A in BCG effectively after transformation. The rBCG proteins were recognized by the BZLF1 (LMP2A) antibody. An ELISA demonstrated that rBCG could stimulate the generation of antibody against the fusion protein. The fusion gene was constructed successfully, and the rBCG induced humoral and cellular immune response in mice.

Long-term survival outcomes with intravesical docetaxel for recurrent nonmuscle invasive bladder cancer after previous bacillus Calmette-Guérin therapy

PURPOSE

Docetaxel is a safe agent for intravesical therapy. Adding monthly maintenance treatments can extend response durability. We report our cumulative experience with intravesical docetaxel in a larger cohort with extended followup.

MATERIALS AND METHODS

A total of 54 patients received salvage intravesical docetaxel for bacillus Calmette-Guérin refractory nonmuscle invasive bladder cancer between 2003 and 2012, including 18 treated during the original phase I trial. All patients received 6 weekly instillations of intravesical docetaxel. After the phase I trial, those with a complete response to induction treatment were offered single dose monthly maintenance treatments for a total of up to 12 months of docetaxel therapy. Recurrence was defined as positive biopsy or urine cytology. Recurrence-free, disease specific and overall survival was determined by Kaplan-Meier analysis.

RESULTS

Median followup was 39.1 months. Of the 54 patients 32 (59%) had a complete initial response after induction therapy, including 18 who received additional monthly maintenance treatments. Median time to recurrence in initial responders treated with vs without docetaxel maintenance was 39.3 vs 19.0 months. One and 3-year recurrence-free survival rates for the entire cohort were 40% and 25%, respectively. Of the 54 patients 17 (24%) underwent radical cystectomy at a median of 24 months of followup. Five-year disease specific and overall survival rates were 85% and 71%, respectively.

CONCLUSIONS

Intravesical docetaxel appears to be a promising agent with significant efficacy and durability for bacillus Calmette-Guérin refractory nonmuscle invasive bladder cancer. Adding maintenance treatments may increase the duration of recurrence-free survival.

[Recurrent bladder cancer after BCG instillation therapy. Local therapy options?]

Patients with a so-called BCG failure (Bacillus Calmette-Guérin) constitute an inhomogeneous group of patients. Patients with BCG recurrence or BCG refractive tumors are real BCG failures. Therapeutic options are radical cystectomy and a conservative approach, depending on the individual risk of recurrence and progression. Intravesical chemotherapy with docetaxel or gemcitabine after BCG failure shows some promise whereas second line immunotherapy, the combination of BCG and interferon (INF)-α, is an effective regimen but results need to be confirmed. Device-assisted intravesical strategies, such as mitomycin-EMDA or chemohyperthermia are candidates to keep in mind for the near future. Finally, cystectomy results in the best disease-specific survival in patients with BCG failure.

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.

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.