Efficacy and Safety of MCNA in Patients with Nonmuscle Invasive Bladder Cancer at High Risk for Recurrence and Progression after Failed Treatment with bacillus Calmette-Guérin

Multidisciplinary consensus document on the current treatment of bacille Calmette-Guérin-unresponsive non-muscle invasive bladder tumor

Radical cystectomy is the current treatment of choice for patients with BCG-unresponsive non-muscle invasive bladder tumor (NMIBC). However, the high comorbidity of this surgery and its effects on the quality of life of patients require the investigation and implementation of bladder-sparing treatment options. These must be evaluated individually by the uro-oncology committee based on the characteristics of the BCG failure, type of tumor, patient preferences and treatment options available in each center. Based on FDA-required oncologic outcomes (6-month complete response rate for CIS: 50%; duration of response in responders for CIS and papillary: 30% at 12 months and 25% at 18 months), there is not currently a strong preference for one treatment over another, although the intravesical route seems to offer less toxicity. This work summarizes the evidence on the management of BCG-unresponsive NMIBC based on current scientific evidence and provides consensus recommendations on the most appropriate treatment.

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.

Hyperthermic Intravesical Chemotherapy (HIVEC) Using Epirubicin in an Optimized Setting in Patients with NMIBC Recurrence after Failed BCG Therapy

To evaluate hyperthermic intravesical chemotherapy (HIVEC) using conductive heating and epirubicin in an optimized setting as an alternative to radical cystectomy in patients with recurrent non-muscle invasive bladder cancer (NMIBC) who have failed bacillus Calmette-Guérin (BCG) therapy. We retrospectively analyzed our prospectively recorded database of patients who underwent HIVEC between 11/2017 and 11/2022 at two Swiss University Centers. Cox regression analysis was used for univariate/multivariate analysis, and the Kaplan-Meier method for survival analysis. Of the 39 patients with NMIBC recurrence after failed BCG therapy, 25 (64%) did not recur within the bladder after a median follow-up of 28 months. The 12- and 24-month intravesical RFS were 94.8% and 80%, respectively. Extravesical recurrence developed in 14/39 (36%) of patients. Only 7/39 (18%) patients had to undergo radical cystectomy. Seven patients (18%) progressed to metastatic disease, with five of these (71%) having previously developed extravesical disease. No adverse events > grade 2 occurred during HIVEC. Device-assisted HIVEC using epirubicin in an optimized setting achieved excellent RFS rates in this recurrent NMIBC population at highest risk for recurrence after previously failed intravesical BCG therapy. Extravesical disease during or after HIVEC, however, was frequent and associated with metastatic disease and consecutively poor outcomes.

Novel immunotherapeutic options for BCG-unresponsive high-risk non-muscle-invasive bladder cancer

BACKGROUND

High-risk non-muscle-invasive bladder cancer (HR-NMIBC) presents a challenge to many physicians due to its ability to resist Bacillus Calmette-Guérin (BCG) intravesical therapy and the substantial rate of progression into muscle-invasive bladder cancer (MIBC). Patients who are BCG-unresponsive have worse prognosis and thus require further management including radical cystectomy (RC), which significantly impacts quality of life. Moreover, the ongoing worldwide shortage of BCG warrants the need for policies that prioritize drug use and utilize alternative treatment strategies. Hence, there is a significant unmet need for bladder preserving therapy in this subset of patients.

METHODS

To address this issue, we searched the relevant literature in PUBMED for articles published from 2019 through May of 2023 using appropriate keywords. All clinical trials of patients with HR-NMIBC treated with immune-related agents were retrieved from clinicaltrials.gov.

FINDINGS AND FUTURE PERSPECTIVES

Exploratory treatments for BCG-Unresponsive HR-NMIBC included immune checkpoint inhibitors (ICI), oncolytic viral therapy, cytokine agonists, and other immunomodulators targeting TLR, EpCaM, FGFR, MetAP2, and IDO1. Some combination therapies have been found to work synergistically and are preferred therapeutically over monotherapy. Three drugs-pembrolizumab, valrubicin, and most recently, nadofaragene firadenovec-vncg-have been FDA approved for the treatment of BCG-unresponsive NMIBC in patients who are ineligible for or decline RC. However, all explored treatment options tend to postpone RC rather than provide long-term disease control. Additional combination strategies need to be studied to enhance the effects of immunotherapy. Despite the challenges faced in finding effective therapies, many potential treatments are currently under investigation. Addressing the landscape of biomarkers, mechanisms of progression, BCG resistance, and trial design challenges in HR-NMIBC is essential for the discovery of new targets and the development of effective treatments.

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.

Genitourinary tumors

Memorial Sloan Kettering Cancer Center (MSK) has made many notable contributions to the scientific understanding and care of patients with common urologic cancers. Many of the advances represented paradigm shifts in management and established new standards of care. This review highlights the surgical procedures and treatment strategies originated and pioneered by urologic surgeons and colleagues at MSK during the past 50 years.

Genomic, Metabolic, and Immunological Characterization of GMP-Grade Mycobacterium phlei

Mycobacterium phlei (M. phlei) is an understudied microbe with medical values as an immunomodulating agent. Here, we establish an industrial strain of M. phlei, CUD, and characterize its genomic, metabolic, and immunological profiles. The established strain has been stably passed for more than a decade, indicated by next-generation sequencing of its 5.3 Mb genome. We show that the intramuscular inoculation of heat-inactivated CUD in immunocompetent mice is well tolerated, and can mount immunological responses. Immunophenotyping demonstrates induced innate and adaptive immune responses in peripheral blood, spleen, and inguinal lymph nodes of CUD-treated mice. Using GC-TOF-MS, we find that the metabolomic profiles of different batches are highly concordant. These results demonstrate a highly reproducible production of M. phlei under GMP conditions.

IMPORTANCE Heat-inactivated M. phlei demonstrates promising efficacy to treat BCG-unresponsive non-muscle-invasive bladder cancer patients in clinical trials. However, lack of GMP-grade heat-inactivated M. phlei hampers further clinical investigations. Here, we described a GMP-grade, heat-inactivated M. phlei product, and presented initial characterization of its safety and immunomodulating properties. This product will serve as a starting point for further preclinical studies as well as clinical trials such as in combination with immune checkpoint inhibitors to treat bladder cancer.

Sequential Gemcitabine plus Docetaxel Is the Standard Second-line Intravesical Therapy for Bacillus Calmette-Guérin-unresponsive Non-muscle invasive Bladder Cancer: Con

The use of sequential intravesical instillation of gemcitabine and docetaxel in the management of bacillus Calmette-Guérin-unresponsive non-muscle-invasive bladder cancer should not be recommended as a second-line treatment. First, technical issues are a barrier to broad adoption of this strategy. Second, the low level of evidence supporting this treatment remains weak and needs proper assessment.

European Association of Urology Guidelines on Non-muscle-invasive Bladder Cancer (Ta, T1, and Carcinoma in Situ)

CONTEXT

The European Association of Urology (EAU) has released an updated version of the guidelines on non-muscle-invasive bladder cancer (NMIBC).

OBJECTIVE

To present the 2021 EAU guidelines on NMIBC.

EVIDENCE ACQUISITION

A broad and comprehensive scoping exercise covering all areas of the NMIBC guidelines since the 2020 version was performed. Databases covered by the search included Medline, EMBASE, and the Cochrane Libraries. Previous guidelines were updated, and the level of evidence and grade of recommendation were assigned.

EVIDENCE SYNTHESIS

Tumours staged as Ta, T1 and carcinoma in situ (CIS) are grouped under the heading of NMIBC. Diagnosis depends on cystoscopy and histological evaluation of tissue obtained via transurethral resection of the bladder (TURB) for papillary tumours or via multiple bladder biopsies for CIS. For papillary lesions, a complete TURB is essential for the patient's prognosis and correct diagnosis. In cases for which the initial resection is incomplete, there is no muscle in the specimen, or a T1 tumour is detected, a second TURB should be performed within 2-6 wk. The risk of progression may be estimated for individual patients using the 2021 EAU scoring model. On the basis of their individual risk of progression, patients are stratified as having low, intermediate, high, or very high risk, which is pivotal to recommending adjuvant treatment. For patients with tumours presumed to be at low risk and for small papillary recurrences detected more than 1 yr after a previous TURB, one immediate chemotherapy instillation is recommended. Patients with an intermediate-risk tumour should receive 1 yr of full-dose intravesical bacillus Calmette-Guérin (BCG) immunotherapy or instillations of chemotherapy for a maximum of 1 yr. For patients with high-risk tumours, full-dose intravesical BCG for 1-3 yr is indicated. For patients at very high risk of tumour progression, immediate radical cystectomy should be considered. Cystectomy is also recommended for BCG-unresponsive tumours. The extended version of the guidelines is available on the EAU website at https://uroweb.org/guideline/non-muscle-invasive-bladder-cancer/.

CONCLUSIONS

These abridged EAU guidelines present updated information on the diagnosis and treatment of NMIBC for incorporation into clinical practice.

PATIENT SUMMARY

The European Association of Urology has released updated guidelines on the classification, risk factors, diagnosis, prognostic factors, and treatment of non-muscle-invasive bladder cancer. The recommendations are based on the literature up to 2020, with emphasis on the highest level of evidence. Classification of patients as having low, intermediate, or and high risk is essential in deciding on suitable treatment. Surgical removal of the bladder should be considered for tumours that do not respond to bacillus Calmette-Guérin (BCG) treatment and tumours with the highest risk of progression.

A BCG success story: From prevention of tuberculosis to optimal bladder cancer treatment

BCG remains the most important vaccine for tuberculosis 100 years after its first use, and over the past 4 decades it has become the most widely accepted, effective drug used in the treatment of aggressive localized bladder cancer. This review chronicles the narrow path that led to approval and world-wide acceptance of BCG immunotherapy for bladder cancer while immunotherapy trials in other malignancies were abandoned. Six intravesical instillations of 5x10^8 CFU of BCG weekly after bladder tumor resection, first reported in 1976, is superior to resection alone and resection plus intravesical chemotherapy. Maintenance of effective immune stimulation is surprisingly difficult, but 3 weekly treatments 3, 6, and 12, 18, 24, 30 and 36 months after induction produces further significant reduction in tumor recurrence. This 3 week BCG maintenance schedule alone has reduced disease progression and mortality in multicenter randomized clinical trials. In the new age of immuno-oncology patients with many types of cancer now benefit from immunotherapy, but currently these modern agents are prohibitively expensive for most of the world. In contrast, the low cost and therefore low profitability of BCG has resulted in recurrent shortages that threaten both bladder cancer patients and children at risk for tuberculosis and other serious infections. Humanity has greatly benefited from early 20th century science that developed BCG and the benevolence of doctors Calmette and Guerin who put people over profit and widely shared cultures of the vaccine. The 21st century is bringing new immunotherapies and greatly expanding the types of malignancies that can be treated. Recombinant technology is expected to improve both the efficacy and production of BCG, hopefully expanding the availability of BCG and relieving the recurring supply shortage for both vaccination and cancer therapy.

Early PDD Cystoscopy after BCG Induction for High-risk Non-Muscle Invasive Bladder Cancer Significantly Increased the Detection of BCG-refractory Tumors

OBJECTIVES

To compare the detection rate of BCG refractory tumors between white light cystoscopy (WL-C) and Photodynamic Diagnosis cystoscopy (PDD-C).

METHODS

We performed a monocentric retrospective study that included all consecutive patients with high-risk non-muscle-invasive bladder cancer (NMIBC) diagnosed from January 2017 to January 2021. All patients had an initial Transurethral resection of bladder tumor (TURBT) with PDD ± restaging TURBT if needed, followed by full-dose BCG induction. Within 8 weeks following BCG induction all patients had both WL-C and PDD-C under general anesthesia ± TURBT in case of suspicious lesion. The primary endpoint was the detection of bladder cancer (BC) at post-BCG cystoscopy.

RESULTS

A total of 136 consecutive patients met inclusion criteria. Initial BC characteristics were: 35.6% of T1 tumor, 92.6% high-grade and 48.6% associated cis. BC was diagnosed in 33/136 cases (24%) at early PDD-C after BCG induction: 77% Ta, 23% T1, 56% associated cis, 68% high grade and 6% MIBC. Sensibility and Specificity of WL-C and PDD-C: 41 vs 91% (p<0.001) and 86 vs 75% (p=0.001). PDD-C detected 16 additional tumors: 81.3% Ta, 18.7% T1, 75% associated cis and 75% high grade.

CONCLUSIONS

Systematic use of PDD after BCG induction increased the detection of BCG-refractory tumors and lead to significant modification in the treatment of high-risk NMIBC. Future studies are needed to evaluate long-term oncological benefit of early PDD reevaluation and its cost-effectiveness.

The current landscape of salvage therapies for patients with bacillus Calmette-Guérin unresponsive nonmuscle invasive bladder cancer

PURPOSE OF REVIEW

Although radical cystectomy represents the gold standard treatment for patients with high-risk nonmuscle invasive bladder cancer (NMIBC) whose disease does not respond to bacillus Calmette-Guérin (BCG), many patients are unable or unwilling to undergo surgery. The need remains for effective bladder-preserving therapies. This review aims to describe existing treatments, contemporary research in this field and ongoing trials of salvage therapies for patients with BCG-unresponsive NMIBC.

RECENT FINDINGS

Intravesical chemotherapy has been utilized frequently in this setting. Emerging data on combination regimens such as intravesical gemcitabine and docetaxel and intravesical cabazitaxel, gemcitabine and cisplatin are promising; nevertheless, larger, prospective trials are needed. Meanwhile, the intravenous checkpoint inhibitor pembrolizumab was recently FDA-approved for patients BCG-unresponsive NMIBC. Encouraging clinical trial results for intravesical nadofaragene firadenovec, oportuzumab monatox and ALT-803 + BCG have been released, while data from trials of other treatment strategies, including novel chemotherapy and drug delivery, augmented BCG immunotherapy, adenoviral and gene therapy, targeted therapy, and combination systemic immunotherapy with intravesical agents, are eagerly awaited.

SUMMARY

Several novel salvage therapies offer promise for patients with BCG-unresponsive NMIBC. Patient selection, efficacy, safety, cost and ease of administration must be carefully considered to determine the optimal treatment approach.

Immunostimulatory Response of RWFV Peptide-Targeted Lipid Nanoparticles on Bladder Tumor Associated Cells

Bladder carcinoma is the most expensive tumor type to treat on a cost-per-patient basis from diagnosis to death. Treatment with Bacillus Calmette Guerin (BCG) instillation is the only approved immunotherapy in the clinic for the remission of superficial bladder carcinoma. Unfortunately, frequent relapses, high local morbidity, risk of systemic mycobacterial infection, and occasional supply chain interruptions limit the utility of BCG for bladder cancer treatment. It is well known that BCG utilizes an adhesin protein known as fibronectin attachment protein that possesses a crucial RWFV peptide sequence for binding to the bladder tumor microenvironment prior to the initiation of the immunotherapeutic response. We report a RWFV-targeted, pH-responsive stabilized lipid nucleic acid nanoparticle (LNP) vehicle for the effective delivery of an immunotherapeutic oligonucleotide, CpG, that is assembled using a glass microfluidic Chemtrix 3221 reactor. Our small-angle X-ray scattering studies revealed a layer-by-layer assembly of the oligonucleotides with a repeat distance of 6.04 nm within the LNP. Using flow cytometry to evaluate the different cell types found in the bladder tumor microenvironment, RWFV-targeted LNPs were found to attach specifically to fibronectin-secreting cells in culture during a 2 h incubation period. The trafficking and cellular fate of these targeted LNPs were revealed by confocal microscopy of RAW264.7 macrophages to enter the endocytotic pathway within 4 h post treatment. Importantly, control studies reveal that only the pH-sensitive LNP formulation is capable of efficiently releasing the payload within 12 h. As a result, the targeted pH-sensitive LNP resulted in higher expression levels of costimulatory molecules CD83, CD 86, and MHC II, while also inducing higher levels of TNF-α secretion from macrophages. These results demonstrate that RWFV-targeted, pH-sensitive LNP formulations are capable of maximum immunotherapeutic response, potentially making them a highly efficient, lower risk, and readily manufactured alternative to BCG immunotherapy.

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.

Immunotherapy in Bacillus Calmette-Guerin (BCG) unresponsive nonmuscle invasive bladder cancer

PURPOSE OF REVIEW

A number of promising therapies for Bacillus Calmette-Guerin (BCG) unresponsive nonmuscle invasive bladder cancer (NMIBC) are in the pipeline. In this review, we discuss the history of immunotherapy for the treatment of NMIBC and future developments, focusing on novel intravesical treatments.

RECENT FINDINGS

The term BCG unresponsive NMIBC encompasses patients with both BCG refractory and BCG relapsing disease. This definition was adopted to standardize inclusion criteria for patients enrolling in clinical trials in this setting. A host of intravesical immuno-oncologic therapies that include gene therapies, oncolytic viruses, cell surface molecule delivered immunotoxins, and cytokine driven agonism of cellular immunity, are in various phases of the drug development pipeline. In addition, pembrolizumab, an immune-checkpoint inhibitor, has recently been approved as a treatment option for BCG unresponsive NMIBC.

SUMMARY

Patients with BCG unresponsive disease face many difficulties. Although radical cystectomy is the most effective treatment option for these patients, it is associated with significant morbidity, difficult recovery challenges, and refusal by many patients. Cancer immunotherapies may provide bladder sparing options for some patients who develop BCG unresponsive disease.

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.

Trained immunity as a molecular mechanism for BCG immunotherapy in bladder cancer

Intravesical BCG instillation is the gold-standard adjuvant immunotherapy for patients with high-risk non-muscle-invasive bladder cancer. However, the precise mechanism of action by which BCG asserts its beneficial effects is still unclear. BCG has been shown to induce a non-specific enhancement of the biological function in cells of the innate immune system, creating a de facto heterologous immunological memory that has been termed trained immunity. Trained immunity or innate immune memory enables innate immune cells to mount a more robust response to secondary non-related stimuli after being initially primed (or trained) by a challenge such as BCG. BCG-induced trained immunity is characterized by the metabolic rewiring of monocyte intracellular metabolism and epigenetic modifications, which subsequently lead to functional reprogramming effects, such as an increased production of cytokines, on restimulation. Results from BCG vaccination studies in humans show that trained immunity might at least partly account for the heterologous beneficial effects of BCG vaccination. Additionally, immunity might have a role in the effect of BCG immunotherapy for bladder cancer. Based on these indications, we propose that trained immunity could be one of the important mechanisms mediating BCG immunotherapy and could provide a basis for further improvements towards a personalized approach to BCG therapy in non-muscle-invasive bladder cancer.

Evidence-based Assessment of Current and Emerging Bladder-sparing Therapies for Non-muscle-invasive Bladder Cancer After Bacillus Calmette-Guerin Therapy: A Systematic Review and Meta-analysis

CONTEXT

Currently, there is no standard of care for patients with non-muscle-invasive bladder cancer (NMIBC) who recur despite bacillus Calmette-Guerin (BCG) therapy. Although radical cystectomy is recommended, many patients decline to undergo or are ineligible to receive it. Multiple agents are being investigated for use in this patient population.

OBJECTIVE

To systematically synthesize and describe the efficacy and safety of current and emerging treatments for NMIBC patients after treatment with BCG.

EVIDENCE ACQUISITION

A systematic literature search of MEDLINE, Embase, and the Cochrane Controlled Register of Trials (period limited to January 2007-June 2019) was performed. Abstracts and presentations from major conference proceedings were also reviewed. Randomized controlled trials were assessed using the Cochrane risk of bias tool. Data for single-arm trials were pooled using a random-effect meta-analysis with the proportions approach. Trials were grouped based on the minimum number of prior BCG courses required before enrollment and further stratified based on the proportion of patients with carcinoma in situ (CIS).

EVIDENCE SYNTHESIS

Thirty publications were identified with data from 23 trials for meta-analysis, of which 17 were single arm. Efficacy and safety outcomes varied widely across studies. Heterogeneity across trials was reduced in subgroup analyses. The pooled 12-mo response rates were 24% (95% confidence interval [CI]: 16-32%) for trials with two or more prior BCG courses and 36% (95% CI: 25-47%) for those with one or more prior BCG courses. In a subgroup analysis, inclusion of ≥50% of patients with CIS was associated with a lower response.

CONCLUSIONS

The variability in efficacy and safety outcomes highlights the need for consistent endpoint reporting and patient population definitions. With promising emerging treatments currently in development, efficacious and safe therapeutic options are urgently needed for this difficult-to-treat patient population.

PATIENT SUMMARY

We examined the efficacy and safety outcomes of treatments for non-muscle-invasive bladder cancer after bacillus Calmette-Guerin therapy. Outcomes varied across studies and patient populations, but emerging treatments currently in development show promising efficacy.

Salvage therapeutic strategies for bacillus Calmette-Guerin failure

PURPOSE OF REVIEW

To give an overview of current options for conservative treatment of patients failing intravesical bacillus Calmette-Guerin (BCG) and to discuss emerging approaches with potential future clinical applications.

RECENT FINDINGS

Radical cystectomy is the standard-of-care for patients failing BCG therapy. In patients unfit or unwilling to undergo surgery, salvage therapy options could be proposed with the aim to offer local cancer control and prevent progression to muscle-invasive disease. Salvage treatments have been conducted using intravesical chemotherapy regimens, chemoradiation or chemohyperthermia. Intravesical agents such as valrubicin, gemcitabine or docetaxel showed response rates varying between 16 and 40%, whereas combination treatments of gemcitabine with docetaxel or mitomycin reported response rates in up to 50% of all patients with durable responses in about one out of three patients. For chemohyperthermia, 2-year recurrence rates between 41 and 56% have been reported. Ongoing clinical trials are evaluating chemoradiation as well as novel approaches such as systemic immunotherapy, viral gene therapy, targeted therapy or vaccination strategies with promising preliminary outcomes.

SUMMARY

Salvage therapeutic bladder-sparing strategies for BCG failure such as intravesical chemotherapy or chemoradiation should currently only be considered in patients unfit for or refusing surgery. Innovative concepts such as chemohyperthermia, checkpoint inhibitors, targeted therapy or viral gene therapy could lead to major changes in clinical management of BCG failures in the future.

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.

Bacillus Calmette-Guérin (BCG) Therapy for Bladder Cancer: An Update

Physicians treating patients affected by nonmuscle-invasive bladder cancer (NMIBC) have been in shock during the last six years since manufacturing restrictions on the production of the first-option medicine, Mycobacterium bovis Bacillus Calmette-Guérin (BCG), have resulted in worldwide shortages. This shortage of BCG has led to a rethinking of the established treatment guidelines for the rationing of the administration of BCG. Some possible schedule modifications consist of a decrease in the length of maintenance treatment, a reduction in the dose of BCG in intravesical instillations or the use of different BCG substrains. All these strategies have been considered valuable in times of BCG shortage. In addition, the lack of availability of BCG has also led to the general recognition of the need to find new treatment options for these patients so that they are not dependent on a single treatment. Few alternatives are committed to definitively replacing BCG intravesical instillations, but several options are being evaluated to improve its efficacy or to combine it with other chemotherapeutic or immunotherapeutic options that can also improve its effect. In this article, we review the current state of the treatment with BCG in terms of all of the aforementioned aspects.

European Association of Urology Guidelines on Non-muscle-invasive Bladder Cancer (TaT1 and Carcinoma In Situ) - 2019 Update

CONTEXT

This overview presents the updated European Association of Urology (EAU) guidelines for non-muscle-invasive bladder cancer (NMIBC), TaT1, and carcinoma in situ (CIS).

OBJECTIVE

To provide practical recommendations on the clinical management of NMIBC with a focus on clinical presentation and recommendations.

EVIDENCE ACQUISITION

A broad and comprehensive scoping exercise covering all areas of the NMIBC guidelines has been performed annually since the last published version in 2017. Databases covered by the search included Medline, EMBASE, and the Cochrane Libraries. Previous guidelines were updated, and the level of evidence and grade of recommendation were assigned.

EVIDENCE SYNTHESIS

Tumours staged as Ta, T1, and/or CIS are grouped under the heading of NMIBC. Diagnosis depends on cystoscopy and histological evaluation of the tissue obtained by transurethral resection (TURB) in papillary tumours or by multiple bladder biopsies in CIS. In papillary lesions, a complete TURB is essential for the patient's prognosis and correct diagnosis. Where the initial resection is incomplete, where there is no muscle in the specimen, or where a T1 tumour is detected, a second TURB should be performed within 2-6 wk. The risks of both recurrence and progression may be estimated for individual patients using the European Organisation for Research and Treatment of Cancer (EORTC) scoring system. Stratification of patients into low-, intermediate-, and high-risk groups is pivotal to the recommendation of adjuvant treatment. In patients with tumours presumed to be at a low risk and in those presumed to be at an intermediate risk with a low previous recurrence rate and an expected EORTC recurrence score of <5, one immediate chemotherapy instillation is recommended. Patients with intermediate-risk tumours should receive 1 yr of full-dose bacillus Calmette-Guérin (BCG) intravesical immunotherapy or instillations of chemotherapy for a maximum of 1 yr. In patients with high-risk tumours, full-dose intravesical BCG for 1-3 yr is indicated. In patients at the highest risk of tumour progression, immediate radical cystectomy should be considered. Cystectomy is recommended in BCG-unresponsive tumours. The extended version of the guidelines is available at the EAU website: https://uroweb.org/guideline/non-muscle-invasive-bladder-cancer/.

CONCLUSIONS

These abridged EAU guidelines present updated information on the diagnosis and treatment of NMIBC for incorporation into clinical practice.

PATIENT SUMMARY

The European Association of Urology Non-muscle-invasive Bladder Cancer (NMIBC) Panel has released an updated version of their guidelines, which contains information on classification, risk factors, diagnosis, prognostic factors, and treatment of NMIBC. The recommendations are based on the current literature (until the end of 2018), with emphasis on high-level data from randomised clinical trials and meta-analyses. Stratification of patients into low-, intermediate-, and high-risk groups is essential for deciding appropriate use of adjuvant intravesical chemotherapy or bacillus Calmette-Guérin (BCG) instillations. Surgical removal of the bladder should be considered in case of BCG-unresponsive tumours or in NMIBCs with the highest risk of progression.

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.

Mycobacterium bovis BCG in metastatic melanoma therapy

Melanoma is the most aggressive form of skin cancer, with a high mortality rate and with 96,480 new cases expected in 2019 in the USS. BRAF^V600E, the most common driver mutation, is found in around 50% of melanomas, contributing to tumor growth, angiogenesis, and metastatic progression. Dacarbazine (DTIC), an alkylate agent, was the first chemotherapeutic agent approved by the US Food and Drug Administration (FDA) used as a standard treatment. Since then, immunotherapies have been approved for metastatic melanoma (MM) including ipilimumab and pembrolizumab checkpoint inhibitors that help decrease the risk of progression. Moreover, Mycobacterium bovis Bacillus Calmette-Guerin (BCG) serves as an adjuvant therapy that induces the recruitment of natural killer NK, CD4⁺, and CD8⁺ T cells and contributes to antitumor immunity. BCG can be administered in combination with chemotherapeutic and immunotherapeutic agents and can be genetically manipulated to produce recombinant BCG (rBCG) strains that express heterologous proteins or overexpress immunogenic proteins, increasing the immune response and improving patient survival. In this review, we highlight several studies utilizing rBCG immunotherapy for MM in combination with other therapeutic agents.

Hyperthermic Intravesical Chemotherapy for BCG Unresponsive Non-Muscle Invasive Bladder Cancer Patients

Background:

Adjuvant intravesical instillations with bacillus Calmette-Guérin (BCG) is the recommended treatment option for patients with intermediate-and high-risk non-muscle invasive bladder cancer (NMIBC). Despite adequate BCG treatment, a large proportion of patients experience a recurrence. Although radical cystectomy is the gold standard for BCG unresponsive NMIBC, some patients are unfit or unwilling to consider this option.

Objective:

To assess the effectiveness of Hyperthermic IntraVEsical Chemotherapy (HIVEC^®) in BCG unresponsive NMIBC patients.

Methods:

A post-hoc analysis was conducted of prospectively included intermediate-and high-risk NMIBC patients who were planned to receive HIVEC^® treatment between October 2014 and November 2017. For the present analysis, only patients who met the BCG unresponsive definition were included. Patients were followed by cystoscopy and cytology every 3 months and a CT-urography scan yearly. The primary outcome was the disease-free survival (DFS). The Common Terminology Criteria for Adverse Events (CTCAE) was used to assess side-effects.

Results:

The study population consisted of 55 BCG unresponsive NMIBC patients of whom 52 underwent≥5 HIVEC^® treatments. The median age and follow-up were 73 years and 14.0 months (IQR 7.6 – 24.6). The median DFS was 17.7 months (SE 6.72) and progression occurred in four patients. The 1-year cumulative incidence rate of disease recurrence/progression was 53%. Two patients experienced severe side-effects (CTCAE≥3).

Conclusions:

HIVEC^® seems a valid treatment option for BCG unresponsive NMIBC patients. We report a median DFS of 17.7 months (SE 6.72), potentially avoiding or postponing the need for radical surgery in a proportion of these patients.

Effects of intravesical therapy with platelet-rich plasma (PRP) and Bacillus Calmette-Guérin (BCG) in non-muscle invasive bladder cancer

This study describes the effects of a promising therapeutic alternative for non-muscle invasive bladder cancer (NMIBC) based on Bacillus Calmette-Guerin (BCG) intravesical immunotherapy combined with Platelet-rich plasma (PRP) in an animal model. Furthermore, this study describes the possible mechanisms of this therapeutic combination involving Toll-like Receptors (TLRs) 2 and 4 signaling pathways. NMIBC was induced by treating female Fischer 344 rats with N-methyl-N-nitrosourea (MNU). After treatment with MNU, the animals were distributed into four experimental groups: Control (without MNU) group, MNU (cancer) group, MNU + PRP group, MNU + BCG group and MNU + PRP + BCG group. Our results demonstrated that PRP treatment alone or associated with BCG triggered significant cytotoxicity in bladder carcinoma cells (HTB-9). Animals treated with PRP associated to BCG clearly showed better histopathological recovery from the cancer state and decrease of urothelial neoplastic lesions progression in 70% of animals when compared to groups that received the same therapies administered singly. In addition, this therapeutic association led to distinct activation of immune system TLRs 2 and 4-mediated, resulting in increased MyD88, TRIF, IRF3, IFN-γ immunoreactivities. Taken together, the data obtained suggest that interferon signaling pathway activation by PRP treatment in combination with BCG immunotherapy may provide novel therapeutic approaches for non-muscle invasive bladder cancer.

Effects of an immune stimulant, inactivated Mycobacterium phlei, on the growth performance as well as meat quality of fattening pigs

Inactivated mycobacterium phlei (M. phlei) is well known for its immune-stimulatory functions in humans and livestock, but less information is available about the influence on meat quality of pigs when used as a feed additive. This study was designed to evaluate the effects of inactivated M. phlei on growth performance as well as meat quality of fattening pigs. A total of 240 cross-bred pigs ([Landrace × Yorkshire] × Duroc) with initial body weight of 80.14 ± 0.29 kg were randomly allocated to five treatments, each of which consisted of eight replicates with 6six pigs per replicate. The basal diet supplemented with five levels of inactivated M. phlei preparations (0, 3.5 × 10⁹ [0.1% w/w], 7 × 10⁹ [0.2%], 1.4 × 10¹⁰ [0.4%] or 2.1 × 10¹⁰ [0.6%] colony-forming units/kg) was respectively fed to the control group and four treatment groups for 30 days. Adding 0.4% of inactivated M. phlei to diet increased the average daily feed intake and average daily gain of pigs. Importantly, intramuscular fat percentage in the Longissimus dorsi (LD) was increased by feeding diet containing 0.2%, 0.4% and 0.6% of inactivated M. phlei, despite the pH value, drip loss, cooking loss and filter paper fluid uptake not being influenced. Analysis of the fatty acid components showed that some saturated fatty acids were decreased in LD after feeding inactivated M. phlei, but some monounsaturated fat acids (MUFAs) and polyunsaturated fatty acids were increased (PUFAs), which induced the total contents of MUFAs and PUFAs were improved. RT-PCR assay revealed that feeding inactivated M. phlei up-regulated genes implicated in fat metabolism in muscle, including ELOVL6, FASN, SCD1 and H-FABP. This study revealed that feeding inactivated M. phlei not only increased growth performance of fattening pigs, but also improved the meat quality by increasing intramuscular fat content, thus inactivated M. phlei probably has high utilization value in modern pig production.

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.

Nonmuscle-invasive bladder cancer: what's changing and what has changed

PURPOSE

Nonmuscle-invasive bladder cancer (NMIBC) is a challenging disease to manage primarily due to its varied clinical course. The management of NMIBC has witnessed a widespread change with respect to its diagnosis and treatment. Although transurethral resection (TUR) and adjuvant bacillus Calmette-Guerin (BCG) stills remain the cornerstone, newer protocols has come into vogue to achieve optimal care. On the basis of a literature review, we aimed to establish 'what changes has already occurred and what is expected in the future' in NMIBC.

METHODS

A Medline search was performed to identify the published literature with respect to diagnosis, treatment and future perspectives on NMIBC. Particular emphasis was directed to determinants such as the quality of TUR and the newer modifications, Re-TUR, current status of newer macroscopic and microscopic imaging, role of urinary biomarkers, clinical, histologic and molecular predictors of high-risk disease, administration of intravesical agents, salvage therapy in BCG recurrence and the current best practice guidelines were analyzed.

RESULTS AND CONCLUSIONS

Optimal TUR, restaging in select group, incorporation of newer endoscopic imaging and judicious administration of intravesical chemo-immunotherapeutic agents can contribute to better patient care. Although there is a plethora of urinary markers, there is insufficient evidence for their use in isolation. The future probably lies in identification of genetic markers to determine disease recurrence, nonresponders to standard treatment and early institution of alternative/targeted therapy.

Efficacy of Mycobacterium Phlei Cell Wall-Nucleic Acid Complex (MCNA) in BCG-Unresponsive Patients

Background: We have previously reported the results of a prospective multi-institutional study on the efficacy of MCNA in patients who recurred after intravesical BCG treatment [1]. Since that publication, a new standardized definition for BCG-unresponsiveness has been established [2]. Objective: We re-analyzed the oncologic outcomes following intravesical MCNA in patients classified as BCG-unresponsive according to the new definition. Methods: For this analysis, we focused on the enrolled patients who satisfied the requirements for BCG Unresponsiveness: i.e. adequate BCG treatment (at least 5/6 induction and 2/3 maintenance instillations) and high grade tumor within 6 months of prior BCG. Treatment course included 6 weekly intravesical instillations of 8 mg MCNA followed by 3 weekly instillations at months 3, 6, 12, 18, and 24. Followup assessments included cystoscopy, urine cytology and biopsy. Patients absent of high grade disease confirmed by central review of biopsy were deemed disease-free. Results: Of the 129 patients enrolled, 94 (68 CIS with/without papillary tumors, 26 papillary only tumors) fit the criteria for the new BCG Unresponsive definition. Overall, disease free survival (DFS) for all BCG unresponsive patients was 48.9% (95% CI 38.0-59.0%) at 6 months, 34.8% (95% CI 24.7-45%) at 1 year and 28.3% (15.7-34.3%) at 2 years post induction. In the group with papillary tumors, DFS measured at months 6, 12, and 24 were: 61.2% (38.2-77.8%), 61.2(38.2-77.8%), and 50.1% (27.5-69%). In the CIS-containing group, the corresponding DFS were: 44.8% (32.3-56.4%), 26.5% (16.3-37.9%), and 16.6% (8.6-26.9%), respectively. Conclusions: For patients who are BCG Unresponsive, MCNA has the potential to render 26.5% of patients with CIS and 61.2% of patients with papillary tumors disease-free for at least 1 year with an intact bladder. The higher efficacy noted in the true BCG-unresponsive cohort than was previously reported with all-comers emphasizes the importance of having clearly defined criteria for clinical trials investigating new intravesical therapies after BCG failure.

Non-muscle-invasive bladder cancer: Intravesical treatments beyond Bacille Calmette-Guérin

An unmet need exists for patients with high-risk non-muscle-invasive bladder cancer for whom bacille Calmette-Guérin (BCG) has failed and who seek further bladder-sparing approaches. This shortcoming poses difficult management dilemmas. This review explores previously investigated first-line intravesical therapies and discusses emerging second-line treatments for the heterogeneous group of patients for whom BCG has failed. The myriad of recently published and ongoing trials assessing novel salvage intravesical treatments offer promise to patients who both seek an effective cure and want to avoid radical surgery. However, these trials must carefully be contextualized by specific patient, tumor, and recurrence characteristics. As data continue to accumulate, there will potentially be a role for these agents as second-line or even first-line intravesical therapies. Cancer 2017;123:390-400. © 2016 American Cancer Society.

Administration of Mycobacterium phlei cell wall-nucleic acid complex in the immediate postoperative period for the treatment of non-muscle-invasive bladder cancer

INTRODUCTION

This review sought to investigate the safety of intravesical administration of Mycobacterium phlei cell wall-nucleic acid (MCNA) in the immediate postoperative period after biopsy/resection for non-muscle-invasive bladder cancer (NMIBC).

METHODS

Patients with NMIBC who failed bacillus Calmette-Guérin (BCG) therapy and at high risk of recurrence and progression participated in this study. Treatment involved an induction phase of six weeks and maintenance of three weekly instillations every six months for two years. Biopsies were mandatory at six months and resections/biopsies as indicated. Of the 129 patients enrolled, 18 (14%) received one or more instillations of MCNA within 24 hours of an endoscopic procedure for a total of 32 instillations.

RESULTS

Fourteen patients (78%) received MCNA in the immediate postoperative period. Two (11%) received treatment the day after surgery, but a second treatment immediately after a transurethral resection of the bladder tumour (TURBT). The remaining two patients received an instillation each the day after surgery. Adverse events (AEs) occurred in 31.3% of those treated immediately after the procedure; they were mild, limited to the lower urinary tract, and not drug-related. Only one patient experienced systemic symptoms of moderate severity. None of the AEs resulted in postponement of treatment. There were no AEs among those receiving MCNA the day after surgery.

CONCLUSIONS

The dual mechanism of action of MCNA suggests that early treatment would take advantage of its chemotherapeutic (pro-apoptotic) activity. Concerns about early administration due to the presence of live bacteria are circumvented with this sterile preparation. These preliminary results warrant further investigation to confirm the safety of perioperative administration of MCNA.

Potential therapeutic strategies for non - muscle invasive bladder cancer based on association of intravesical immunotherapy with p - mapa and systemic administration of cisplatin and doxorubicin

The present study describes the histopathological and molecular effects of P-MAPA (Protein aggregate magnesium-ammonium phospholinoleate-palmitoleate anhydride) intravesical immunotherapy combined with systemic doxorubicin or cisplatin for treatment of non-muscle invasive bladder cancer (NMIBC) in an appropriate animal model. Our results showed an undifferentiated tumor, characterizing a tumor invading mucosa or submucosa of the bladder wall (pT1) and papillary carcinoma in situ (pTa) in the Cancer group. The histopathological changes were similar between the combined treatment with intravesical P-MAPA plus systemic Cisplatin and P-MAPA immunotherapy alone, showing decrease of urothelial neoplastic lesions progression and histopathological recovery in 80% of the animals. The animals treated systemically with cisplatin or doxorubicin singly, showed 100% of malignant lesions in the urinary bladder. Furthemore, the combined treatment with P-MAPA and Doxorubicin showed no decrease of urothelial neoplastic lesions progression and histopathological recovery. Furthermore, Akt, PI3K, NF-kB and VEGF protein levels were significantly lower in intravesical P-MAPA plus systemic cisplatin and in intravesical P-MAPA alone treatments than other groups. In contrast, PTEN protein levels were significantly higher in intravesical P-MAPA plus systemic cisplatin and in intravesical P-MAPA alone treatments. Thus, it could be concluded that combination of intravesical P-MAPA immunotherapy and systemic cisplatin in the NMIBC animal model was effective, well tolerated and showed no apparent signs of antagonism between the drugs. In addition, intravesical P-MAPA immunotherapy may be considered as a valuable option for treatment of BCG unresponsive patients that unmet the criteria for early cystectomy.

Nonmuscle invasive bladder cancer: a primer on immunotherapy

Intravesical Bacillus Calmette-Guérin (BCG) has long been the gold standard treatment of nonmuscle invasive bladder cancer. Recently, there has been an emergence of novel immunotherapeutic agents, which have shown promise in the treatment of urothelial cell carcinoma. These agents aim to augment, modify, or enhance the immune response. Such strategies include recombinant BCG, monoclonal antibodies, vaccines, gene therapy, and adoptive T-cell therapy. Here, we review the emerging immunotherapeutics in the treatment of nonmuscle invasive bladder cancer.

Immunotherapy for the Treatment of Urothelial Carcinoma

PURPOSE

We review the biological mechanisms of action, clinical safety and efficacy of immunotherapies for urothelial carcinoma. We also describe current areas of research in immunotherapy, and highlight ongoing trials and promising and novel investigational agents.

MATERIALS AND METHODS

Data were obtained by a search of PubMed®, ClinicalTrials.gov and Cochrane databases for English language articles published through February 2016. Applicable abstracts from recent Society of Urologic Oncology, European Association of Urology, American Urological Association and ASCO® meetings were used.

RESULTS

Bacillus Calmette-Guérin is one of the most successful immunotherapies in cancer treatment and remains the gold standard of care for patients with high risk, nonmuscle invasive bladder cancer, with initial response rates of approximately 70%. However, with the exception of valrubicin and standard chemotherapeutics there is a paucity of available treatment options for patients with recurrence or progression to more advanced disease. Recently there has been significant interest in novel immunotherapeutic agents in the management of cases where bacillus Calmette-Guérin fails, as well as cases of more advanced cancer. These investigational therapies can generally be classified into several broad categories, including recombinant bacillus Calmette-Guérin and cell wall derived therapies, cytokines, gene therapy, cancer vaccines, immune checkpoint inhibitors, oncolytic viruses, adoptive immunotherapies and immune agonists, as well as several additional immunomodulatory agents. The majority of these agents are currently under investigation in phase I or II clinical trials. Recently investigators reported evidence that inhibition of the PD-1/PD-L1 pathway has clinical activity in patients with advanced bladder cancer. These findings, along with successful phase III trials and U.S. Food and Drug Administration approvals of other checkpoint inhibitors in melanoma, nonsmall cell lung cancer and renal cell carcinoma, ultimately led to Food and Drug Administration approval of atezolizumab for advanced disease, the first new treatment approved for advanced urothelial carcinoma in 20 years.

CONCLUSIONS

While bacillus Calmette-Guérin has demonstrated significant clinical efficacy in the treatment of patients with bladder cancer, additional therapies are needed for those in whom bacillus Calmette-Guérin fails, as well as for those with advanced disease. Immunotherapy for urothelial carcinoma remains a promising and active area of research, and numerous agents, particularly the monoclonal antibodies targeting checkpoint inhibition pathways, are showing encouraging signs of clinical activity.

Increased toll-like receptors and p53 levels regulate apoptosis and angiogenesis in non-muscle invasive bladder cancer: mechanism of action of P-MAPA biological response modifier

BACKGROUND

The new modalities for treating patients with non-muscle invasive bladder cancer (NMIBC) for whom BCG (Bacillus Calmette-Guerin) has failed or is contraindicated are recently increasing due to the development of new drugs. Although agents like mitomycin C and BCG are routinely used, there is a need for more potent and/or less-toxic agents. In this scenario, a new perspective is represented by P-MAPA (Protein Aggregate Magnesium-Ammonium Phospholinoleate-Palmitoleate Anhydride), developed by Farmabrasilis (non-profit research network). This study detailed and characterized the mechanisms of action of P-MAPA based on activation of mediators of Toll-like Receptors (TLRs) 2 and 4 signaling pathways and p53 in regulating angiogenesis and apoptosis in an animal model of NMIBC, as well as, compared these mechanisms with BCG treatment.

RESULTS

Our results demonstrated the activation of the immune system by BCG (MyD88-dependent pathway) resulted in increased inflammatory cytokines. However, P-MAPA intravesical immunotherapy led to distinct activation of TLRs 2 and 4-mediated innate immune system, resulting in increased interferons signaling pathway (TRIF-dependent pathway), which was more effective in the NMIBC treatment. Interferon signaling pathway activation induced by P-MAPA led to increase of iNOS protein levels, resulting in apoptosis and histopathological recovery. Additionally, P-MAPA immunotherapy increased wild-type p53 protein levels. The increased wild-type p53 protein levels were fundamental to NO-induced apoptosis and the up-regulation of BAX. Furthermore, interferon signaling pathway induction and increased p53 protein levels by P-MAPA led to important antitumor effects, not only suppressing abnormal cell proliferation, but also by preventing continuous expansion of tumor mass through suppression of angiogenesis, which was characterized by decreased VEGF and increased endostatin protein levels.

CONCLUSIONS

Thus, P-MAPA immunotherapy could be considered an important therapeutic strategy for NMIBC, as well as, opens a new perspective for treatment of patients that are refractory or resistant to BCG intravesical therapy.

Mycobacteria emulsified in olive oil-in-water trigger a robust immune response in bladder cancer treatment

The hydrophobic composition of mycobacterial cell walls leads to the formation of clumps when attempting to resuspend mycobacteria in aqueous solutions. Such aggregation may interfere in the mycobacteria-host cells interaction and, consequently, influence their antitumor effect. To improve the immunotherapeutic activity of Mycobacterium brumae, we designed different emulsions and demonstrated their efficacy. The best formulation was initially selected based on homogeneity and stability. Both olive oil (OO)- and mineral oil-in-water emulsions better preserved the mycobacteria viability and provided higher disaggregation rates compared to the others. But, among both emulsions, the OO emulsion increased the mycobacteria capacity to induce cytokines’ production in bladder tumor cell cultures. The OO-mycobacteria emulsion properties: less hydrophobic, lower pH, more neutralized zeta potential, and increased affinity to fibronectin than non-emulsified mycobacteria, indicated favorable conditions for reaching the bladder epithelium in vivo. Finally, intravesical OO-M. brumae-treated mice showed a significantly higher systemic immune response, together with a trend toward increased tumor-bearing mouse survival rates compared to the rest of the treated mice. The physicochemical characteristics and the induction of a robust immune response in vitro and in vivo highlight the potential of the OO emulsion as a good delivery vehicle for the mycobacterial treatment of bladder cancer.

Bacillus Calmette-Guérin (BCG) Treatment Failures with Non-Muscle Invasive Bladder Cancer: A Data-Driven Definition for BCG Unresponsive Disease

Objective: To create the first data-driven definition for those unlikely to benefit from further BCG treatment.

Materials and Methods: The database created for the Phase 2 BCG-Interferon-α 2B (IFN) study was queried and BCG failure patients were identified (n = 334). Full study protocols have previously been published. Separate models were constructed for analysis of patients with any CIS (pure or concomitant) and pure papillary disease. Variables considered included age, gender, stage, grade, tumor size and focality (for papillary only), number of prior BCG courses, and prior BCG failure interval.

Results: Patients with recurrent CIS within 6 months of their most recent prior BCG course (HR 2.56, p <  0.01) and ≥2 prior BCG failures (HR 1.54, p <  0.01) responded worst to repeat intravesical therapy. Those with CIS recurrence at 6–12 months did not differ from those recurring within 6 months (HR = 0.88, p = 0.71). Patients with recurrent papillary disease within 6 months (HR 1.82, p = 0.02), ≥2 BCG failures (HR 1.54, p = 0.03), and multifocal disease (HR 2.05, p <  0.01) responded worst to therapy. Patients with T1 disease remained disease free in 38% of cases (24–51% 95% CI) at 2 years with low rates of progression.

Conclusions: Patients who fail two courses of BCG with either persistent or recurrent multifocal papillary disease within 6 months or CIS within 12 months of their prior BCG should be considered BCG unresponsive. Recurrent T1 disease respond reasonably well to another course with low progression rates but further investigation is warranted.