A phase I trial of intravesical nanoparticle albumin-bound paclitaxel in the treatment of bacillus Calmette-Guérin refractory nonmuscle invasive bladder cancer

Experimental and New Approaches for Bladder Preservation in Intermediate and High-Risk Non-Muscle-Invasive Bladder Cancer (NMIBC)

About 75% of bladder cancers are detected as non-muscle invasive. High-risk patients have high progression risk. Although the standard is transurethral resection of bladder tumor plus full dose intravesical BCG for one to 3 years, due to the high risk of progression, radical cystectomy may be considered in specific cases. Although radical cystectomy is still the best approach for high-grade NMIBC from an oncological perspective, its high morbidity and impact on quality of life motivate studies of new strategies that may reduce the need for cystectomy. We carried out a mini-review whose objectives were: 1 - to identify bladder-sparing alternatives that are being studied as possible treatment for patients with intermediate and high-risk NMIBC; 2 - understand the evidence that exists regarding success rate, follow-up, and side effects of different strategies. Several studies have sought alternatives for bladder preservation, including immunotherapy, intravesical chemotherapy, chemo-hyperthermia, antibody-drug conjugates, viral genetic therapy, and others with promising results. The selection of an optimal therapy for high-risk NMIBC that can reduce the need for cystectomy, with low toxicity and high efficacy, is of paramount importance and remains an issue, however, several known medications are being tested as bladder-preserving alternatives in this scenario and have shown promise in studies.

A systematic review of nanocarriers for treatment of urologic cancers

Nanocarriers (NCs) are a form of nanotechnology widely investigated in cancer treatment to improve the safety and efficacy of systemic therapies by increasing tumor specificity. Numerous clinical trials have explored the use of NCs in urologic cancers since the approval of the first NCs for cancer treatment over 20 years ago. The objective of this systematic review is to examine the effectiveness and safety of NCs in treating urological cancers. This paper summarizes the state of the field by investigating peer-reviewed, published results from 43 clinical trials involving the use of NCs in bladder, prostate, and kidney cancer patients with a focus on safety and efficacy data. Among the 43 trials, 16 were phase I, 20 phase II, and 4 phase I/II. No phase III trials have been reported. While both novel and classic NCs have been explored in urologic cancers, NCs already approved for the treatment of other cancers were more widely represented. Trials in prostate cancer and mixed trials involving both urologic and non-urologic cancer patients were the most commonly reported trials. Although NCs have demonstrable efficacy with adequate safety in non-urologic cancer patient populations, current clinical stage NC options appear to be less beneficial in the urologic cancer setting. For example, nab-paclitaxel and liposomal doxorubicin have proven ineffective in the treatment of urologic cancers despite successes in other cancers. However, several ongoing pre-clinical studies using targeted and locally applied improved NCs may eventually improve their utility.

Local Drug Delivery in Bladder Cancer: Advances of Nano/Micro/Macro-Scale Drug Delivery Systems

Treatment of bladder cancer remains a critical unmet need and requires advanced approaches, particularly the development of local drug delivery systems. The physiology of the urinary bladder causes the main difficulties in the local treatment of bladder cancer: regular voiding prevents the maintenance of optimal concentration of the instilled drugs, while poor permeability of the urothelium limits the penetration of the drugs into the bladder wall. Therefore, great research efforts have been spent to overcome these hurdles, thereby improving the efficacy of available therapies. The explosive development of nanotechnology, polymer science, and related fields has contributed to the emergence of a number of nanostructured vehicles (nano- and micro-scale) applicable for intravesical drug delivery. Moreover, the engineering approach has facilitated the design of several macro-sized depot systems (centimeter scale) capable of remaining in the bladder for weeks and months. In this article, the main rationales and strategies for improved intravesical delivery are reviewed. Here, we focused on analysis of colloidal nano- and micro-sized drug carriers and indwelling macro-scale devices, which were evaluated for applicability in local therapy for bladder cancer in vivo.

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.

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.

Novel Delivery Mechanisms for Existing Systemic Agents and Emerging Therapies in Bladder Cancer

Systemic agents including immune checkpoint inhibitors, antibody-drug conjugates, and targeted therapies play a critical role in the management of bladder cancer. Novel localized delivery mechanisms for existing systemic agents explore solutions to improve treatment response without compromising safety. Herein, we review the contemporary innovations in modern intravesical agents, hyperthermic drug delivery, reverse-thermal gels, nanocarriers, gene therapy, and subcutaneous therapies.

A longitudinal single center analysis of T1HG bladder cancer: An 18 year experience

OBJECTIVES

To re-evaluate the treatment of T1HG bladder cancer by analyzing our experience over 18 years.

METHODS AND MATERIALS

An IRB-approved, single-institution retrospective review was performed of all patients with T1HG bladder cancer between August 1999 and July 2017. We assessed clinicopathologic characteristics, treatment history (including intravesical therapy, cystectomy, systemic chemotherapy, and radiation), and oncologic outcomes.

RESULTS

We identified 191 patients with T1HG. Five patients underwent cystectomy at diagnosis. The five-year recurrence-free survival (RFS) for the 186 patients who initially underwent bladder sparing treatments was 50% (95% CI: 41%-58%). There were 83 patients (45%) with disease recurrence; median time to recurrence was 6.7 months (IQR: 4.9-17.5). Disease characteristics at initial recurrence was T2 or greater in 8 patients (10%), T1HG in 19 (23%), CIS in 30 (36%), TaHG in 10 (12%), T1 low-grade (LG) in 1 (1%), and TaLG in 15 (18%). For patients with no prior recurrences, neither re-resection (P = 0.12), receipt of induction therapy (P = 0.81), prostatic urethra positivity (P = 0.51), or age (P = 0.34) were significantly associated with risk of recurrence. Similarly, patients with a single recurrence also fared well without identifiable risk factors. In fact, baseline hazard function analysis demonstrated no differences in RFS comparing patients stratified by 0, 1, and 2+ prior recurrences (P = 0.46). The five-year overall survival (OS) was 76% (95% CI: 68%-82%), and median OS was 127 months. The five-year cancer-specific survival was 86% (95% CI: 78%-91%) for the overall cohort. Five-year cystectomy-free survival for patients with BCG responsive disease and unresponsive disease was 95% (95% CI: 85%-98%) and 72% (95% CI: 52%-84%), respectively.

CONCLUSION

For patients who recurred after intravesical therapy, including those with recurrent T1 disease, additional induction courses of intravesical therapy did not negatively affect oncologic outcomes. Pathology of initial recurrence was not found to be a statistically significant risk factor for future recurrence. These findings suggest that BCG-unresponsive disease does not necessarily require immediate cystectomy. A multicenter, pragmatically designed evaluation in a contemporary cohort would more validly interrogate this important patient population.

Biodegradable ring-shaped implantable device for intravesical therapy of bladder disorders

Intravesical instillation is an efficient drug delivery route for the local treatment of various urological conditions. Nevertheless, intravesical instillation is associated with several challenges, including pain, urological infection, and frequent clinic visits for catheterization; these difficulties support the need for a simple and easy intravesical drug delivery platform. Here, we propose a novel biodegradable intravesical device capable of long-term, local drug delivery without a retrieval procedure. The intravesical device is composed of drug encapsulating biodegradable polycaprolactone (PCL) microcapsules and connected by a bioabsorbable Polydioxanone (PDS) suture with NdFeB magnets in the end. The device is easily inserted into the bladder and forms a 'ring' shape optimized for maximal mechanical stability as informed by finite element analysis. In this study, inserted devices were retained in a swine model for 4 weeks. Using this device, we evaluated the system's capacity for delivery of lidocaine and resiquimod and demonstrated prolonged drug release. Moreover, a cost-effectiveness analysis supports device implementation compared to the standard of care. Our data support that this device can be a versatile drug delivery platform for urologic medications.

Nanomedicine for urologic cancers: diagnosis and management

Urologic cancers accounted for more than 2 million new cases and around 0.8 million deaths in 2020. Although surgery, chemotherapy, and radiotherapy, as well as castration for prostate cancer, remain the cornerstones for managing urologic neoplasms, they can result in severe adverse effects, poor patient compliance, and unsatisfactory survival rates, thus, it is essential to develop novel options that enable the early detection of these malignancies, together with providing accurate diagnoses, and more efficient treatment strategies. Nanomedicine represents an emerging approach that can deliver formulations or drugs across traditional biological barriers in the body and be directed to specific cell types within target organs via active targeting or passive targeting, thus, showing potential to improve the management of urologic cancers. In this review, we discussed the most recent updates on the application of nanomedicines in the diagnosis and treatment of urologic cancers, with focus on prostate, bladder and kidney tumors. We also presented the anti-tumor molecular mechanisms of newly designed nanomedicine for treating urologic cancers, mainly including image-guided surgery, chemotherapy, radiotherapy, gene therapy, immunotherapy, and their synergetic therapy. Current studies have demonstrated the potential advantages of nanomedicine over conventional approaches. However, most developments and new findings in this area have not been validated in clinical trials yet, and therefore, efforts shall be made to translate these research insights into clinical practices for urologic cancers.

Development of sustained-release drug-loaded intravesical inserts via semi-solid micro-extrusion 3D-printing for bladder targeting

Discontinued treatment and non-adherence are oftentimes weaknesses of common first-line drug therapy against bladder conditions due to their negative side-effects. To overcome these limitations and increase patients' quality of life, intravesical therapies are continuously being explored. 3D-printing offers the possibility of freely tailoring drug delivery systems to manufacture indwelling devices that may administer drugs locally over an extended time and avoiding frequently repeated administrations while minimizing systemic side-effects. In the present work, pressure-assisted micro syringe printing has been used to develop flexible drug-loaded inserts applicable via common urinary catheter that can remain up to several weeks inside the urinary bladder. Three APIs (lidocaine hydrochloride, trospium chloride (TrCl) and hydrochlorothiazide (HCT)) with different properties and solubilities were investigated for their applicability together with two different pharmaceutical polymers (biodegradable polycaprolactone (PCL) and non-degradable ethylene vinyl acetate copolymer (EVA)). The fastest release was thereby observed for the PCL-TrCl combination and the slowest for EVA-HCT depending on the API's solubility in the dissolution medium and formation of API clusters within the matrix. It was further demonstrated that the dissolution profile could be modified by adapting drug loads between 5 and 15 % or the geometry of the printed inserts indicating the possibility of tailoring release profiles.

Application of nanotechnology in the diagnosis and treatment of bladder cancer

Bladder cancer (BC) is a common malignancy in the genitourinary system and the current theranostic approaches are unsatisfactory. Sensitivity and specificity of current diagnosis methods are not ideal and high recurrence and progression rates after initial treatment indicate the urgent need for management improvements in clinic. Nanotechnology has been proposed as an effective method to improve theranosis efficiency for both non-muscle invasive bladder cancer (NMIBC) and muscle invasive bladder cancer (MIBC). For example, gold nanoparticles (AuNPs) have been developed for simple, fast and sensitive urinary sample test for bladder cancer diagnosis. Nanoparticles targeting bladder cancers can facilitate to distinguish the normal and abnormal bladder tissues during cystoscopy and thus help with the complete removal of malignant lesions. Both intravenous and intravesical agents can be modified by nanotechnology for targeted delivery, high anti-tumor efficiency and excellent tolerability, exhibiting encouraging potential in bladder cancer treatment. Photosensitizers and biological agents can also be delivered by nanotechnology, intermediating phototherapy and targeted therapy. The management of bladder cancer remained almost unchanged for decades with unsatisfactory effect. However, it is likely to change with the fast-developed nanotechnology. Herein we summarized the current utility of nanotechnology in bladder cancer diagnosis and treatment, providing insights for the future designing and discovering novel nanoparticles for bladder cancer management.

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.

Precision oncology: myth or reality?

Cancer incidence rates are growing at an alarming pace pressing for the development of innovative personalized approaches to treating this disease. The absence of clinical symptoms in the early stages delays the onset of adequate treatment. Traditional therapies are not always as effective as they should be and do not guarantee long-lasting relapse-free survival. Metastatic cancers pose a particular challenge to healthcare professionals. This review touches upon the immunologic mechanisms underlying the development of malignancies, talks about conventional and innovative therapeutic modalities, such as targeted, gene or specific immunotherapies, and analyzes the literature on the use of different approaches that form a basis for precision oncology.

Enhanced taxane uptake into bladder tissues following co-administration with either mitomycin C, doxorubicin or gemcitabine: association to exfoliation processes

OBJECTIVE

To investigate the effect of three anticancer drugs (mitomycin c (MMC), doxorubicin or gemcitabine) on bladder wall morphology and the uptake of paclitaxel or docetaxel following coadministration. The primary objective of this study was to measure the uptake of MMC, doxorubicin or gemcitabine with or without exposure of the tissue to amine terminated cationic nanoparticles (CNPs) and to investigate any possible exfoliation effects of the three drugs on intact bladder tissue. The secondary objective was to investigate the uptake of taxane drugs (docetaxel, DTX) and paclitaxel, (PTX) from surfactant micelle formulations in the presence of MMC, doxorubicin or gemcitabine.

MATERIALS AND METHODS

Sections of fresh pig bladder tissue were incubated in Franz diffusion cells with the urothelial side exposed to solutions of doxorubicin, MMC and gemcitabine containing radioactive drug for 90 min. Some tissue samples were simultaneously exposed to each of the three drugs in combination with the surfactant micelle formulations of PTX (Taxol) or DTX (Taxotere). Tissue sections were then cryostat sectioned for drug quantitation by liquid scintillation counting or fixed for scanning electron microscopy and haematoxylin and eosin staining.

RESULTS

All three drugs caused exfoliation of the urothelial layer of bladder tissues. Drug uptake studies showed that all three drugs effectively penetrated the lamina propria through to the muscular layer over a 2-h incubation and these levels were unaffected by pre-treatment with CNPs. The uptake levels of the taxane drugs PTX and DTX were significantly enhanced following simultaneous treatment of bladders with MMC, doxorubicin or gemcitabine.

CONCLUSION

The exfoliation effects of MMC, doxorubicin and gemcitabine allow for good tissue penetration of these drugs with no additional effect from CNP treatment of bladders. The observed exfoliation effect of these amine-containing drugs probably arises from a cationic interaction with the mucus and urothelium cell layer in a manner similar to that previously reported for CNPs. These studies suggest that the lack of long-term clinical efficacy of these drugs may not arise from poor intravesical drug penetration but may result from a rapid diffusion of the drugs into the deeper vascularised muscular region with rapid drug clearance. The enhanced uptake of PTX or DTX following co-administration with MMC, doxorubicin or gemcitabine probably arises from the removal of the urothelial barrier by exfoliation allowing for improved taxane partitioning into superficial layers. These effects may allow for dual drug intravesical strategies offering greatly improved taxane uptake and potential additive drug effects for improved efficacy.

Potential Applications of Nanotechnology in Urological Cancer

Nowadays, the potential scope of nanotechnology in uro-oncology (cancers of the prostate, bladder, and kidney) is broad, ranging from drug delivery, prevention, and diagnosis to treatment. Novel drug delivery methods using magnetic nanoparticles, gold nanoparticles, and polymeric nanoparticles have been investigated in prostate cancer. Additionally, renal cancer treatment may be profoundly influenced by applications of nanotechnology principles. Various nanoparticle-based strategies for kidney cancer therapy have been proposed. Partly due to the dilution of drug concentrations by urine production, causing inadequate drug delivery to tumor cells in the treatment of bladder cancer, various multifunctional bladder-targeted nanoparticles have been developed to enhance therapeutic efficiency. In each of these cancer research fields, nanotechnology has shown several advantages over widely used traditional methods. Different types of nanoparticles improve the solubility of poorly soluble drugs, and multifunctional nanoparticles have good specificity toward prostate, renal, and bladder cancer. Moreover, nanotechnology can also combine with other novel technologies to further enhance effectivity. As our understanding of nanotechnologies grows, additional opportunities to improve the diagnosis and treatment of urological cancer are excepted to arise. In this review, we focus on nanotechnologies with potential applications in urological cancer therapy and highlight clinical areas that would benefit from nanoparticle therapy.

Nano-BCG: A Promising Delivery System for Treatment of Human Bladder Cancer

Mycobacterium bovis bacillus Calmette–Guerin (BCG) remains at the forefront of immunotherapy for treating bladder cancer patients. However, the incidence of recurrence and progression to invasive cancer is commonly observed. There are no established effective intravesical therapies available for patients, whose tumors recur following BCG treatment, representing an important unmet clinical need. In addition, there are very limited options for patients who do not respond to or tolerate chemotherapy due to toxicities, resulting in poor overall treatment outcomes. Within this context, nanotechnology is an emergent and promising tool for: (1) controlling drug release for extended time frames, (2) combination therapies due to the ability to encapsulate multiple drugs simultaneously, (3) reducing systemic side effects, (4) increasing bioavailability, (5) and increasing the viability of various routes of administration. Moreover, bladder cancer is often characterized by high mutation rates and over expression of tumor antigens on the tumor cell surface. Therapeutic targeting of these biomolecules may be improved by nanotechnology strategies. In this mini-review, we discuss how nanotechnology can help overcome current obstacles in bladder cancer treatment, and how nanotechnology can facilitate combination chemotherapeutic and BCG immunotherapies for the treatment of non-muscle invasive urothelial bladder cancer.

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.

Increased endocytosis of magnetic nanoparticles into cancerous urothelial cells versus normal urothelial cells

The blood-urine barrier is the tightest and most impermeable barrier in the body and as such represents a problem for intravesical drug delivery applications. Differentiation-dependent low endocytotic rate of urothelial cells has already been noted; however, the differences in endocytosis of normal and cancer urothelial cells have not been exploited yet. Here we analysed the endocytosis of rhodamine B isothiocyanate-labelled polyacrylic acid-coated cobalt ferrite nanoparticles (NPs) in biomimetic urothelial in vitro models, i.e., in highly and partially differentiated normal urothelial cells, and in cancer cells of the papillary and invasive urothelial neoplasm. We demonstrated that NPs enter papillary and invasive urothelial neoplasm cells by ruffling of the plasma membrane and engulfment of NP aggregates by macropinocytotic mechanism. Transmission electron microscopy (TEM) and spectrophotometric analyses showed that the efficacy of NPs delivery into normal urothelial cells and intercellular space is largely restricted, while it is significantly higher in cancer urothelial cells. Moreover, we showed that the quantification of fluorescent NP internalization in cells or tissues based on fluorescence detection could be misleading and overestimated without TEM analysis. Our findings contribute to the understanding of endocytosis-mediated cellular uptake of NPs in cancer urothelial cells and reveal a highly selective mechanism to distinguish cancer and normal urothelial cells.

A pH-sensitive stearoyl-PEG-poly(methacryloyl sulfadimethoxine)-decorated liposome system for protein delivery: An application for bladder cancer treatment

Stealth pH-responsive liposomes for the delivery of therapeutic proteins to the bladder epithelium were prepared using methoxy-poly(ethylene glycol)5kDa-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (mPEG5kDa-DSPE) and stearoyl-poly(ethylene glycol)-poly(methacryloyl sulfadimethoxine) copolymer (stearoyl-PEG-polySDM), which possesses an apparent pKa of 7.2. Liposomes of 0.2:0.6:100, 0.5:1.5:100 and 1:3:100 mPEG5kDa-DSPE/stearoyl-PEG-polySDM/(soybean phosphatidylcholine+cholesterol) molar ratios were loaded with bovine serum albumin (BSA) as a protein model. The loading capacity was 1.3% w/w BSA/lipid. At pH7.4, all liposome formulations displayed a negative zeta-potential and were stable for several days. By pH decrease or addition to mouse urine, the zeta potential strongly decreased, and the liposomes underwent a rapid size increase and aggregation. Photon correlation spectroscopy (PCS) and transmission electron microscopy (TEM) analyses showed that the extent of the aggregation depended on the stearoyl-PEG-polySDM/lipid molar ratio. Cytofluorimetric analysis and confocal microscopy showed that at pH6.5, the incubation of MB49 mouse bladder cancer cells and macrophages with fluorescein isothiocyanate-labelled-BSA (FITC-BSA) loaded and N-(Lissamine Rhodamine B sulfonyl)-1, 2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine triethylammonium salt (rhodamine-DHPE) labelled 1:3:100 mPEG5kDa-DSPE/stearoyl-PEG-polySDM/lipid molar ratio liposomes resulted in a time-dependent liposome association with the cells. At pH7.4, the association of BSA-loaded liposomes with the MB49 cells and macrophages was remarkably lower than at pH6.5. Confocal images of bladder sections revealed that 2h after the instillation, liposomes at pH7.4 and control non-responsive liposomes at pH7.4 or 6.5 did not associate nor delivered FITC-BSA to the bladder epithelium. On the contrary, the pH-responsive liposome formulation set at pH6.5 and soon administered to mice by bladder instillation showed that, 2h after administration, the pH-responsive liposomes efficiently delivered the loaded FITC-BSA to the bladder epithelium.

Phase 1b Trial to Evaluate Tissue Response to a Second Dose of Intravesical Recombinant Adenoviral Interferon α2b Formulated in Syn3 for Failures of Bacillus Calmette-Guerin (BCG) Therapy in Nonmuscle Invasive Bladder Cancer

BACKGROUND

A phase 1b trial was conducted to evaluate the duration of interferon-alpha (IFNα) production after intravesical administration of recombinant adenovirus-mediated interferon α2b (Ad-IFN) formulated with the excipient Syn3. The primary aim was to determine whether a second instillation 3 days after initial treatment produced prolonged urinary IFN production.

METHODS

The study enrolled seven patients who experienced recurrent non-muscle invasive bladder cancer after bacillus Calmette-Guerin therapy. Each treatment consisted of intravesical instillation of SCH721015 (Syn3) and Ad-IFN at a concentration of 3 × 10¹¹ particles/mL to a total volume of 75 mL given on days 1 and 4. The patients were followed for 12 weeks, during which the magnitude and duration of gene transfer were determined by urine INFα levels. Drug efficacy was determined by cystoscopy and biopsy, and patients who had no recurrence at 12 weeks were eligible for a second course of treatment.

RESULTS

Seven patients were treated with an initial course (instillation on days 1 and 4). Two of the patients had a complete response at 12 weeks and received a second course of treatment. One patient remained without evidence of recurrence after a second course (total 24 weeks). One patient experienced a non-treatment-associated adverse event. Despite a transient rise in IFNα levels, sustained production was not demonstrated.

CONCLUSION

Previously, Ad-IFNα intravesical therapy has shown promising drug efficacy. A prior phase 1 trial with a single instillation compared similarly with the current study, suggesting that a second instillation is not necessary to achieve sufficient urinary IFNα levels.

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.

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.

Management of carcinoma in situ of the bladder: best practice and recent developments

Management of carcinoma in situ of the bladder remains a complex and challenging endeavor due to its high rate of recurrence and progression. Although it is typically grouped with other nonmuscle invasive bladder cancers, its higher grade and aggressiveness make it a unique clinical entity. Intravesical bacillus Calmette-Guérin is the standard first-line treatment given its superiority to other agents. However, high rates of bacillus Calmette-Guérin failure highlight the need for additional therapies. Radical cystectomy has traditional been the standard second-line therapy, but additional intravesical therapies may be more appealing for non-surgical candidates and patients refusing cystectomy. The subject of this review is the treatment strategies and available therapies currently available for carcinoma in situ of the bladder. It discusses alternative intravesical treatment options for patients whose condition has failed to respond to bacillus Calmette-Guérin therapy and who are unfit or unwilling to undergo cystectomy.

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.

Advances in intravesical therapy for urinary tract disorders

INTRODUCTION

Intravesical therapy is a valuable option in the clinical management of urinary tract disorders such as interstitial cystitis/ painful bladder syndrome (IC/PBS) and refractory overactive bladder. This review will cover the latest advances in this field using polymer and liposomes as delivery platform for drugs, protein and nucleic acids.

AREAS COVERED

This review summarizes the significance of intravesical therapy for lower urinary tract disorders. The recent advancement of liposomes as a drug delivery platform for botulinum toxin, tacrolimus and small interfering RNA is discussed. The importance of polymers forming indwelling devices and hydrogels are also discussed, where all preparations improved efficacy parameters in rodent models. Clinical experience of treating IC/PBS with indwelling devices and liposomes are summarized and preclinical evidence about the downregulation of target gene expression in rodent bladder with liposomes complexed with siRNA is also reviewed.

EXPERT OPINION

There have been several advances in the field of intravesical therapy for improving clinical outcomes. One of the most promising research avenues is the repurposing of drugs, given previously by other routes of administration, such as tacrolimus. Intravesical therapy also opens up novel therapeutic targets with improved efficacy and safety for underactive bladder.

Management of T1 Urothelial Carcinoma of the Bladder: What Do We Know and What Do We Need To Know?

T1 bladder cancer constitutes approximately 25% of incident bladder cancers, and as such carries an important public health impact. Notably, it has a heterogeneous natural history, with large variation in reported oncologic outcomes. Optimal risk-stratification is essential to individualize patient management, targeting those at greatest risk of progression for aggressive therapies such as early cystectomy, while allowing others to safely pursue bladder-preserving approaches including intravesical bacillus Calmette-Guerrin (BCG). Current strategies for diagnosis, risk-stratification, and treatment are imperfect, but emerging technologies and molecular approaches represent exciting opportunities to advance clinical paradigms in management of this disease entity.

Optimal treatment of non-muscle invasive urothelial carcinoma including perioperative management revisited

Non-muscle invasive urothelial carcinoma is a heterogeneous disease that requires the practicing urologist to implement a variety of surgical and non-surgical treatment strategies. The disease course can range from recurrent low grade papillary disease to aggressive disease concerning for progression from initial presentation. Depending on the particular patient and goals of care, treatments similarly span the range from minimally invasive fulgurations to immediate radical cystectomy. For most patients some form of intravesical therapy will bridge the gap between transurethral resections (TUR) and radical surgery. Recent advances in the field continue to emphasize the importance of quality TUR and its strong impact on outcomes. In addition, continued research to optimize intravesical therapies has provided more information about how, when, and in whom these agents should be utilized to enhance their efficacy. This review covers the current state of NMIBC and the standards of care for the management of this disease.

Urovision 2020: The future of urology

Urology, as a specialty, has always been at the forefront of innovation and research. Newer technologies have been rapidly embraced and, in many cases, improved upon in order to achieve better patient outcomes. This review addresses the possible future directions that technological advances in urology may take. The role of further miniaturization of urolithiasis treatment, robotic surgery and other minimally invasive techniques is addressed. The potential for enhanced imaging and diagnostic techniques like magnetic resonance imaging and ultrasonography modifications, as well as the potential applications of nanotechnology and tissue engineering, are reviewed.

This article is based on the Dr. Sitharaman Best Essay award of the Urological Society of India for 2013.

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.

Nanotechnology in bladder cancer: current state of development and clinical practice

Nanotechnology is being developed for the diagnosis and treatment of both nonmyoinvasive bladder cancer (NMIBC) and invasive bladder cancer. The diagnostic applications of nanotechnology in NMIBC mainly focus on tumor identification during endoscopy to increase complete resection of bladder cancer while nanotechnology to capture malignant cells or their components continues to be developed. The therapeutic applications of nanotechnology in NMIBC are to reformulate biological and cytotoxic agents for intravesical instillation, combine both diagnostic and therapeutic application in one nanoformulation. In invasive and advanced bladder cancer, magnetic resonance imaging with supraparamagnetic iron oxide nanoparticles can improve the sensitivity and specificity in detecting small metastasis to lymph nodes. Nanoformulation of cytotoxic agents can potentially decrease the toxicity while increasing efficacy.

Phase II trial of intravesical nanoparticle albumin bound paclitaxel for the treatment of nonmuscle invasive urothelial carcinoma of the bladder after bacillus Calmette-Guérin treatment failure

PURPOSE

Response rates to current second line intravesical therapies for recurrent nonmuscle invasive bladder cancer range between 10% and 30%. Nanoparticle albumin bound (nab-)paclitaxel has increased solubility and lower toxicity compared to other taxanes. Results of the phase I intravesical trial of this compound demonstrated minimal toxicity during dose escalation. We now report the results of a phase II trial to assess efficacy.

MATERIALS AND METHODS

This study was an investigator initiated, single center, single arm, phase II trial investigating the use of nab-paclitaxel in patients with recurrent Tis, T1 and Ta urothelial carcinoma in whom at least 1 prior regimen of intravesical bacillus Calmette-Guérin failed. Patients received 500 mg/100 ml nab-paclitaxel administered in 6 weekly intravesical instillations. Efficacy was evaluated with cystoscopy, biopsy, cytology and imaging. If complete response was achieved, patients were treated with full dose monthly maintenance treatments for 6 months.

RESULTS

A total of 28 patients were enrolled in the study. Of these patients 10 (35.7%) exhibited a complete response after initial treatment. At 1 year all of these responses remained durable after maintenance therapy. At a mean followup of 21 months (range 5 to 47) 19 of 28 (67.8%) patients retained their bladders without progression or distant metastases. A single patient had progression to muscle invasive disease at radical cystectomy. Treatment related adverse events were noted in 9 of 28 (32.1%) patients and were limited to grade 1 or 2.

CONCLUSIONS

Intravesical nab-paclitaxel has minimal toxicity and a 35.7% response rate in patients with nonmuscle invasive bladder cancer and previous bacillus Calmette-Guérin failure. Complete response remained durable at 1 year followup in this heavily pretreated patient population.

Advances in intravesical therapy for the treatment of non-muscle invasive bladder cancer (Review)

The knowledge of tumor biology and the biomechanical properties of the urothelium have led to significant advances in the development of intravesical therapy for the treatment of non-muscle invasive bladder cancer (NMIBC). Targeted therapy improves the efficacy and decreases the side effects of antineoplastic agents. Nanoparticles that target antitumor agents to the urothelial cells have allowed for improved delivery of these agents to tumor cells. Gene therapy is another strategy that has allowed for a targeted induction of an antitumor response. Finally, engineering of the bacillus Calmette-Guérin (BCG) vaccine aimed to minimize the potential side effects associated with this treatment. These novel approaches hold promise for decreasing the rate of progression and recurrence of NMIBC.

Expert review: an update in current and developing intravesical therapies for non-muscle-invasive bladder cancer

Non-muscle-invasive bladder cancer is a highly prevalent disease and recurrences, after initial therapy, are common. Consequently, the healthcare costs for non-muscle-invasive bladder cancer are high. Despite a primary adequate response to adjuvant intravesical treatment, many patients suffer from recurrences, and some even from progression. To date, cystectomy remains the only option for those non-responding patients with high risk of recurrence and progression. Mainly because outcome after progression, in this group, is poor. Therefore, new intravesical therapies are needed. Moreover, new accurate and individual parameters, to distinguish responder from non-responders, will provide additional benefit in clinical decision-making. In this review, current diagnostics and therapies will be discussed. In addition, we will elucidate developing therapies in non-muscle-invasive bladder cancer.

A pilot clinical trial of intravesical mitomycin-C and external deep pelvic hyperthermia for non-muscle-invasive bladder cancer

PURPOSE

This paper aims to evaluate the safety and heating efficiency of external deep pelvic hyperthermia combined with intravesical mitomycin C (MMC) as a novel therapy for non-muscle-invasive bladder cancer (NMIBC).

MATERIALS AND METHODS

We enrolled subjects with bacillus Calmette-Guérin (BCG) refractory NMIBC to an early phase clinical trial of external deep pelvic hyperthermia (using a BSD-2000 device) combined with MMC. Bladders were heated to 42 °C for 1 h during intravesical MMC treatment. Treatments were given weekly for 6 weeks, then monthly for 4 months. Heating parameters, treatment toxicity, and clinical outcomes were systematically measured.

RESULTS

Fifteen patients were enrolled on the clinical trial. Median age was 66 years and 87% were male. Median European Organisation for Research and Treatment of Cancer (EORTC) recurrence and progression scores were 6 and 8, respectively. The full treatment course was attained in 73% of subjects. Effective bladder heating was possible in all but one patient who could not tolerate the supine position due to lung disease. Adverse events were all minor (grade 2 or less) and no systemic toxicity was observed. The most common adverse effects were Foley catheter pain (40%), abdominal discomfort (33%), chemical cystitis symptoms (27%), and abdominal skin swelling (27%). With a median follow-up of 3.18 years, 67% experienced another bladder cancer recurrence (none were muscle invasive) and 13% experienced an upper tract recurrence.

CONCLUSIONS

External deep pelvic hyperthermia using the BSD-2000 device is a safe and reproducible method of heating the bladder in patients undergoing intravesical MMC. The efficacy of this treatment modality should be explored further in clinical trials.

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.