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

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.

Recent advancements in the diagnosis and treatment of non-muscle invasive bladder cancer: Evidence update of surgical concept, risk stratification, and BCG-treated disease

In the management of non-muscle invasive bladder cancer (NMIBC), disease progression and long-term control are determined by the intensity of delivered treatment and surveillance and the cancer cells' biological nature. This requires risk stratification-based postoperative management, such as intravesical instillation of chemotherapy drugs, Bacillus Calmette-Guérin (BCG), and radical cystectomy. Advancements in mechanical engineering, molecular biology, and surgical skills have evolved the clinical management of NMIBC. In this review, we describe the updated evidence and perspectives regarding the following aspects: (1) advancements in surgical concepts, techniques, and devices for transurethral resection of the bladder tumor; (2) advancements in risk stratification tools for NMIBC; and (3) advancements in treatment strategies for BCG-treated NMIBC. Repeat transurethral resection, en-bloc transurethral resection, and enhanced tumor visualization, including photodynamic diagnosis and narrow-band imaging, help reduce residual cancer cells, provide accurate diagnosis and staging, and sensitive detection, which are the first essential steps for cancer cure. Risk stratification should always be updated and improved because the treatment strategy changes over time. The BCG-treated disease concept has recently diversified to include BCG failure, resistance, refractory, unresponsiveness, exposure, and intolerance. A BCG-unresponsive disease is an extremely aggressive subset unlikely to respond to a rechallenge with BCG. Numerous ongoing clinical trials aim to develop a future bladder-sparing approach for very high-risk BCG-naïve NMIBC and BCG-unresponsive NMIBC. The key to improving the quality of patient care lies in the continuous efforts to overcome the clinical limitations of bedside management.

Prognostic Role of Preoperative Neutrophil-To-Lymphocyte Ratio (NLR) and Recurrence at First Evaluation after Bacillus Calmette-Guérin (BCG) Induction in Non-Muscle-Invasive Bladder Cancer

We investigated the prognosis of BCG induction-only treatment and non-complete response (CR) at the first 3-month evaluation and examined factors associated with CR. In total, 209 patients with moderate- and high-risk NMIBC who received BCG induction-only treatment between 2008 and 2020 were retrospectively analyzed. Recurrence-free survival (RFS) and progression-free survival (PFS) were assessed based on the initial NMIBC stage. PFS and associated factors of non-CR compared to CR were also assessed. Initial T1 high-grade (HG) (n = 93) had poorer RFS and PFS after BCG induction-only treatment than Ta low-grade (LG) (p = 0.029, p = 0.002). Non-CR (n = 37) had a different neutrophil-to-lymphocyte ratio (NLR) (2.81 ± 1.02 vs. 1.97 ± 0.92) and T staging from CR (p < 0.001, p = 0.008). T1HG recurrence was associated with a worse PFS compared to non-T1HG (13.7 months vs. 101.7 months, p < 0.001). There was no difference in PFS between T1HG and T1LG. T1 and NLR were predictors of response at 3 months in multivariable analysis (p = 0.004, p = 0.029). NLR was also found to be an associated factor with RFS and PFS of bladder cancer (p < 0.001, p < 0.001). BCG induction-only treatment was effective for high-risk TaLG but not for T1HG. T1HG recurrence at 3 months after BCG induction has a poor prognosis for bladder cancer. Preoperative NLR and T1 were predictors of non-CR, and NLR was also associated with the long-term prognosis of bladder cancer.

A Phase 1 Trial of Durvalumab in Combination with Bacillus Calmette-Guerin (BCG) or External Beam Radiation Therapy in Patients with BCG-unresponsive Non-muscle-Invasive Bladder Cancer: The Hoosier Cancer Research Network GU16-243 ADAPT-BLADDER Study

BACKGROUND

Novel treatments and trial designs remain a high priority for bacillus Calmette-Guerin (BCG)-unresponsive non-muscle-invasive bladder cancer (NMIBC) patients.

OBJECTIVE

To evaluate the safety and preliminary efficacy of anti-PD-L1 directed therapy with durvalumab (D), durvalumab plus BCG (D + BCG), and durvalumab plus external beam radiation therapy (D + EBRT).

DESIGN, SETTING, AND PARTICIPANTS

A multicenter phase 1 trial was conducted at community and academic sites.

INTERVENTION

Patients received 1120 mg of D intravenously every 3 wk for eight cycles. D + BCG patients also received full-dose intravesical BCG weekly for 6 wk with BCG maintenance recommended. D + EBRT patients received concurrent EBRT (6 Gy × 3 in cycle 1 only).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Post-treatment cystoscopy and urine cytology were performed at 3 and 6 -mo, with bladder biopsies required at the 6-mo evaluation. The recommended phase 2 dose (RP2D) for each regimen was the primary endpoint. Secondary endpoints included toxicity profiles and complete response (CR) rates.

RESULTS AND LIMITATIONS

Twenty-eight patients were treated in the D (n = 3), D + BCG (n = 13), and D + EBRT (n = 12) cohorts. Full-dose D, full-dose BCG, and 6 Gy fractions × 3 were determined as the RP2Ds. One patient (4%) experienced a grade 3 dose limiting toxicity event of autoimmune hepatitis. The 3-mo CR occurred in 64% of all patients and in 33%, 85%, and 50% within the D, D + BCG, and D + EBRT cohorts, respectively. Twelve-month CRs were achieved in 46% of all patients and in 73% of D + BCG and 33% of D + EBRT patients.

CONCLUSIONS

D combined with intravesical BCG or EBRT proved feasible and safe in BCG-unresponsive NMIBC patients. Encouraging preliminary efficacy justifies further study of combination therapy approaches.

PATIENT SUMMARY

Durvalumab combination therapy can be safely administered to non-muscle-invasive bladder cancer patients with the goal of increasing durable response rates.

Can we offer additional BCG therapy for three-month BCG refractory high grade/T1, Tis bladder cancer patients?

Background

We lack tools to predict treatment and survival outcomes in patients receiving additional BCG therapy as a bladder-preserving therapy in high grade/T1, Tis NMIBC patients who showed persistent/recurrent tumors at three-month follow-up.

Objectives

To assess the predictors of additional BCG response in patients who experienced persistent/recurrent tumors at three-month follow-up after BCG induction.

Patients and methods

We retrospectively analyzed database for NMIBC. Between 2000 and 2019, 231 patients with high-grade T1/Tis NMIBC showed persistent/recurrent tumors at 3-month after BCG-induction, refused or were unfit to radical cystectomy (RC) and were offered additional intravesical BCG as bladder-preserving treatment. Predictors of the outcome after additional BCG were studied using univariate and multivariate logistic regression analysis. Kaplan Meier curve was utilized to estimate the recurrence-free survival (RFS) and progression-free survival (PFS). COX regression analysis was performed to identify independent predictors or RFS and PFS.

Results

During a median (range) of 148 (24-224) months, poor response to additional BCG (tumor recurrence and/or progression) was noted in 112 (48.5%) patients. On multivariate logistic regression analysis, 3-month tumor features (persistent T stage, persistent grade and persistent/new CIS) significantly predicted poor response to additional BCG (OR: 3.4, 95%CI: 1.3-10.8, p = 0.021, OR: 2.1, 95%CI: 1.1-4.1, p = 0.02 and OR: 16.6, 95%CI: 4.5-109, p=<0.001, respectively). The mean RFS was 26 (9-152) months with identified 3-month tumor features (persistent T stage and persistent/new CIS) as independent predictors of RFS (HR = 11.5, 95%CI = 2.7-48.3, p = 0.001 and HR = 2.5, 95%CI = 1.5-4.1, p=<0.001, respectively) on multivariate COX regression analysis. In addition, 3-month tumor features (persistent/new CIS, non-papillary shape and bladder neck involvement) were identified to significantly predict PFS (HR = 6.2, 95%CI = 3.4-11.5, p=<0.001 and HR = 2.3, 95%CI = 1.3-4.3 p = 0.001 and HR = 2.1, 95%CI = 1.2-3.8, p=<0.005, respectively).

Conclusions

Three-month tumor features could be utilized as a tool to predict treatment outcomes and survival benefits when additional intravesical BCG is utilized as a bladder-preserving treatment in patients with recurrent/persistent tumors at three-month follow-up.

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.

International Bladder Cancer Group Consensus Statement on Clinical Trial Design for Patients with Bacillus Calmette-Guérin-exposed High-risk Non-muscle-invasive Bladder Cancer

CONTEXT

A large proportion of patients with non-muscle-invasive bladder cancer (NMIBC) fall in the gap between bacillus Calmette-Guérin (BCG)-naïve and BCG-unresponsive disease. As multiple therapeutic agents move into this gray area, there is a critical need to define the disease state and establish recommendations for optimal trial design.

OBJECTIVE

To develop a consensus on optimal trial design for patients with BCG-exposed NMIBC, defined as high-grade recurrence after BCG treatment that does not meet the criteria for BCG-unresponsive disease.

EVIDENCE ACQUISITION

We conducted a literature review using the Cochrane Library, Medline, and Embase and a review of clinical trials in ClinicalTrials.gov as a basis to generate consensus recommendations for clinical trial design in BCG-exposed NMIBC.

EVIDENCE SYNTHESIS

BCG-exposed NMIBC encompasses BCG resistance (presence of high-grade Ta or carcinoma in situ [CIS] at 3-mo evaluation after induction BCG) and delayed relapse. Randomized controlled trials are required to compare experimental therapies to a control arm receiving additional BCG, although ongoing BCG shortages may impact our ability to follow an optimal trial design. A placebo should be used in combination with BCG if the treatment arm includes BCG plus a study drug. Trials will either need to separate patients with and without CIS into two cohorts, or stratify by the presence of CIS at the time of randomization. If two cohorts are used, the primary endpoint for CIS patients should be complete response within a predetermined time. The primary endpoint in a cohort with Ta/T1 only, or if a single combined cohort is used, should be the duration of event-free survival. Suggested efficacy thresholds and corresponding sample sizes are provided.

CONCLUSIONS

The International Bladder Cancer Group has developed recommendations regarding definitions, endpoints, and clinical trial design for BCG-exposed NMIBC to encourage uniformity among studies in this disease state.

PATIENT SUMMARY

Our consensus provides a precise definition of the disease state for bladder cancer not invading the bladder muscle and exposed to bacillus Calmette-Guérin (BCG) treatment. Clear guidance for conducting optimal clinical trials in this disease setting was established and we believe that this will promote further progress in this field.

Outcomes of Patients with Bacillus Calmette-Guérin (BCG)-Unresponsive Non-Muscle Invasive Bladder Cancer as Defined by the U.S. Food and Drug Administration

BACKGROUND: Limited data are available on the outcomes of patients with non-muscle invasive bladder cancer (NMIBC) unresponsive to intravesical bacillus Calmette-Guérin (BCG), as defined by the United States Food and Drug Administration. OBJECTIVE: To define the outcomes of patients with BCG-unresponsive NMIBC. METHODS: This was a retrospective, single-institution observational cohort study. Records of patients managed at our institution for BCG-unresponsive NMIBC between 2005 and 2020 were reviewed and clinical outcomes evaluated. RESULTS: The study included 149 patients. Management was with initial radical cystectomy in 60 patients (40%) and initial bladder-sparing therapy (BST) in 89 patients (60% ). Overall survival was greater among patients undergoing RC than BST (HR 1.83, 95% CI 1.04–3.22, p = 0.036), potentially due to patient selection, as no significant difference was noted for metastasis-free or cancer-specific survival. Patients opting for initial BST had high rates of treatment failure, with estimated 5-year cystectomy-free survival of only 42% . Patients who received additional lines of BST after a subsequent failure were at increased risk of having ≥pT3 or pN+ disease at cystectomy (42% for ≥2 lines BST, versus 18% for 1 line BST and 15% for initial cystectomy, p = 0.038). CONCLUSION: Among patients who underwent initial BST for BCG-unresponsive NMIBC, rates of treatment failure were very high. Patients who underwent delayed cystectomy after ≥2 lines of BST had elevated rates of extravesical disease. Our observations emphasize the importance of recent and ongoing clinical trials in this clinical space.

Multi-country clinical practice patterns, including use of biomarkers, among physicians’ treatment of BCG-unresponsive non-muscle invasive bladder cancer (NMIBC)

Background

Intravesical bacillus Calmette-Guérin (BCG) fails in a considerable proportion of non-muscle invasive bladder cancer (NMIBC) patients despite treatment per recommended protocol. This real-world study aimed to understand the current patterns of treatment and disease management for the broad BCG-unresponsive NMIBC patient population, alongside collecting sufficient data on patients who do not undergo cystectomy.

Methods

This was a multicenter, retrospective survey of physicians treating BCG-unresponsive NMIBC patients. Data were collected in eight countries – France, Germany, Spain, Italy, United Kingdom, United States, China, and Japan – between January and May 2019. The study consisted of a short online physician survey and a retrospective chart review of eligible BCG-unresponsive NMIBC patients. Physicians abstracted chart data for the last 10 (five patients in Japan) eligible BCG-unresponsive NMIBC patients meeting the inclusion criteria, and the data were analysed for all countries combined using descriptive statistics. Country-specific analyses were also carried out, as appropriate.

Results

Overall, 508 physicians participated in the study. Almost one-quarter (22.9%) of physicians’ current NMIBC patient caseload was BCG-unresponsive, whereby BCG therapy was no longer considered an option. Half of physicians (49.4%) did not regularly use biomarker tests in their practice, with particularly few physicians undertaking biomarker testing in Spain and Japan. Biomarker testing varied considerably, with the proportions of physicians selecting ‘none’ ranging from 11.4% in China to 70.3% in Japan. Physicians reported transurethral resection of the bladder tumor (TURBT) and BCG as the most common current treatments received by their patients. Chemotherapy and anti-PD-L1 treatment options were considered impactful new therapies by 94.7% and 90.0% of physicians surveyed in this study, respectively.

Conclusions

The most common treatments received by patients in this study were TURBT and BCG. Emerging new treatments are driven by exploring biomarkers, but in real-world clinical practice only half of physicians or fewer regularly tested their NMIBC patients for biomarkers; PD-1/PD-L1 was the most common biomarker test used. Most physicians reported that, in addition to chemotherapy, anti-PD-L1 was an impactful new therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-022-00959-z.

Novel and emerging approaches in the management of non-muscle invasive urothelial carcinoma

Non-muscle invasive bladder cancer (NMIBC) has traditionally been managed with transurethral resection followed by intravesical chemotherapy and/or bacillus Calmette-Guerin (BCG) in a risk-adapted manner. These tumors commonly recur and can progress potentially to lethal muscle invasive disease. A major unmet need in the field of NMIBC is bladder preserving therapy for recurrent high-grade NMIBC after adequate intravesical BCG therapy. The current gold standard treatment for these BCG-unresponsive patients is radical cystectomy, which is associated with considerable morbidity and mortality, particularly in older and frailer patients. It is therefore critical to provide alternative treatment options with acceptable oncological outcomes. In this review we explore novel bladder-sparing treatment options including combination intravesical therapy, enhanced instillation methods, immunotherapy, gene therapy, targeted therapy, photodynamic therapy and BCG variants across the spectrum of NMIBC disease states, ranging from low grade BCG-naïve patients through to high-grade BCG-unresponsive NMIBC.

Bacillus Calmette-Guérin-unresponsive non-muscle invasive bladder cancer outcomes in patients without radical cystectomy

BACKGROUND

Bacillus Calmette-Guérin (BCG)-unresponsive non-muscle invasive bladder cancer (NMIBC) is a newly defined subtype that is unlikely to benefit from BCG rechallenge. Radical cystectomy is currently recommended for BCG-unresponsive NMIBC; however, a certain proportion of these patients can be managed with treatments other than that. Herein, we conducted a multicenter retrospective study to analyze the clinical outcomes of BCG-unresponsive NMIBC patients who did not receive radical cystectomy.

METHODS

Of the 141 BCG-unresponsive NMIBC patients, 94 (66.7%) received treatment except radical cystectomy. Survival outcomes were calculated from the date of diagnosis using the Kaplan-Meier method and compared using the log-rank test. Prognostic factors were identified using the multivariate Cox regression model. This group was further classified into three groups according to the number of risk factors, and survival outcomes were compared.

RESULTS

Multivariate analyses identified low estimated glomerular filtration rate (< 45 ml/min/1.73 m²) and large tumor size (≥ 30 mm) before BCG induction as independent poor prognostic factors for progression-free survival and overall survival, while the latter was also an independent factor for cancer-specific survival. The presence of variant histology was an independent poor prognostic factor for overall survival. The high-risk non-cystectomy group showed a significantly poor prognosis for progression-free survival (hazard ratio: 7.61, 95% confidence interval: 2.11-27.5), cancer-specific survival (10.4, 0.54-70.02), and overall survival (8.28, 1.82-37.7).

CONCLUSIONS

Our findings suggest that patients with renal impairment and large tumors should undergo radical cystectomy if the complications and intentions of the patients allow so.

Vaccines Against Tuberculosis: Problems and Prospects (Review)

Despite the efforts of the global medical and scientific community, tuberculosis remains the leading cause of death from infectious diseases. The expectation of success associated with the development of new anti-TB drugs was not justified, and the attention of researchers was largely drawn to the creation of new mycobacterial strains for vaccination against tuberculosis. The proposed review contains current information on the existing vaccine strains and the development of new, genetically engineered strains for the prevention of tuberculosis and the prevention and treatment of other diseases. The review includes relevant information on the correlation between BCG vaccination and the frequency and severity of COVID-19 infection.

Emerging intravesical therapies for the management of bacillus Calmette-Guérin (BCG)-unresponsive non-muscle-invasive bladder cancer: Charting a path forward

Management of patients with bacillus Calmette-Guérin (BCG)-unresponsive, high-risk, non-muscle-invasive bladder cancer (NMIBC) presents a formidable clinical challenge that requires urologists to weigh the competing risks of progression during further intravesical therapy vs. the morbidity of radical cystectomy. The prognosis of high-risk NMIBC recurring after BCG depends on the adequacy of prior BCG, timing of recurrence, and tumor histology. The standard of care is currently radical cystectomy, as effective salvage intravesical therapy has not been established. The development of bladder-sparing treatments has been hampered to date by inconsistent definitions of BCG failure and difficulties in identifying appropriate control treatments in clinical trials. Despite these limitations, the spectrum of salvage therapy is expanding to include enhanced intravesical chemo-, gene, and immuno-therapies. In this review, we provide an overview of these emerging agents in the context of our current understanding of BCG failure and the unique considerations for clinical trial design in this disease state.

Bacillus Calmette-Guérin Salvage Therapy: Definitions and Context

High-risk non-muscle invasive bladder cancer is marked by frequent disease recurrences and risk of stage progression, contributing to high surveillance, treatment-related costs, and patient anxiety. Although the mainstay of high-risk non-muscle invasive bladder cancer clinical management remains transurethral resection followed by intravesical bacillus Calmette-Guérin (BCG), patients who develop BCG-unresponsive disease have few salvage options outside of a radical cystectomy with pelvic lymphadenectomy. This article provides a historical context relevant to the development of the BCG-unresponsive definition, an overview of current clinical trial expectations, and an introduction to this issue of Urologic Clinics.

Identification of Candidates for Salvage Therapy: The Past, Present, and Future of Defining Bacillus Calmette-Guérin Failure

Disease progression and recurrence are common among patients on Bacillus Calmette-Guérin (BCG) therapy, and options for bladder-preserving subsequent therapy remain limited. Ongoing efforts to develop better second-line bladder-sparing therapies rely on clinical trials of patients deemed to have failed management with BCG. This article describes historical definitions of BCG failure, as well as recent efforts to better delineate and refine the clinical criteria for identifying individual patients who will not benefit from further intravesical BCG therapy. It also reviews guidance from the most recent expert consensus panels and professional association guidelines regarding which patients should not receive additional BCG therapy.

Intravesical BCG: where do we stand? Past, present and future

High and intermediate risk non-muscle invasive bladder cancer poses a real challenge for treatment. Approximately 70% of bladder cancer presents as non-muscle invasive and 20–25% will progress to muscle invasive disease. Recurrences occur in up to 70% but treatment options are limited. Intravesical bacillus Calmette–Guérin is still considered the bladder sparing treatment of choice despite its well documented pitfalls. This review considers how bacillus Calmette–Guérin has become the recommended treatment, its benefits and risks and the alternative options for treatment.

Level of evidence: Not applicable for this multicentre audit.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The development of interferon-based gene therapy for BCG unresponsive bladder cancer: from bench to bedside

BACKGROUND AND PURPOSE

BCG unresponsive bladder cancer is an inherently resistant disease state for which the preferred treatment is radical cystectomy. To date, no effective intravesical therapies exist for patients who possess these resistant tumors. For this reason, many research groups are actively investigating/testing novel therapeutic agents to aid in bladder preservation for this patient population. This review article describes our 15-year experience developing and testing IFN-based gene therapy.

METHODS

A comprehensive review was performed of all studies pertaining to IFN-based gene therapy for non-muscle invasive bladder cancer from 2003 to 2018.

RESULTS AND CONCLUSIONS

Over the past two decades, gene therapy has evolved into a powerful tool in our fight against cancer. After overcoming the initial barriers associated with gene delivery to the bladder, we have made significant strides forward in developing this novel therapeutic strategy for the treatment of this inherently resistant disease state. Our results to date are very encouraging; however, much work lies ahead to better understand and optimize this novel approach for treating non-muscle invasive bladder.

Intravesical Radiofrequency-Induced Chemohyperthermia for Carcinoma in Situ of the Urinary Bladder: A Retrospective Multicentre Study

Objective:

To examine the effect of intravesical radiofrequency-induced chemohyperthermia (RF-CHT) in carcinoma in-situ (CIS) patients overall and split according to previously received therapy.

Methods:

CIS patients that underwent an induction and maintenance phase of≥6 RF-CHT instillations, and had either pathology or cystoscopy plus cytology available at 6 months of follow-up were retrospectively included. Complete response (CR), recurrences, cystectomy-free rate, overall survival (OS), and adverse events were evaluated. Analysis was performed for overall, bacillus Calmette-Guérin (BCG)-unresponsive, other BCG-treated, and treatment naïve patients.

Results:

Patients (n = 150) had a mean of 17.5, 9.2, or 0 previous BCG instillations in the BCG-unresponsive (n = 50), other BCG-treated (n = 46, missing n = 4), and treatment naïve groups (n = 47, missing n = 3), respectively. After 6 months, a CR of 46.0%, 71.7%, and 83.0% was found (p < 0.001). Subsequent 2-year recurrence rates were 17.4%, 27.3%, and 12.8%, respectively. The overall cystectomy-free rate and OS at mean follow-up (35.8 months) were 78.5% and 78.0%, respectively. These were 71.4% vs. 84.1% vs. 86.7% (cystectomy-free rate, p = 0.006) and 76.0% vs. 69.6% vs. 87.2% (OS, p = 0.06) for BCG-unresponsive vs. other BCG-treated vs. treatment naïve patients. Progression to muscle-invasive disease was seen in 13.3% of patients. Patients stopped induction or maintenance RF-CHT instillations due to adverse events in respectively 13.4% and 17.8%.

Conclusions:

Intravesical RF-CHT showed good results in both treatment naïve and BCG-treated CIS patients, avoiding the need for cystectomy in 78.5% of cases for at least 3 years with a modest risk of progression. Thus, RF-CHT proves an alternative to cystectomy in selected high-risk patients.

BCG - old workhorse, new skills

Bacille Calmette-Guérin (BCG), the only tuberculosis (TB) vaccine in clinical practice, has limitations in efficacy, immunogenicity and safety. Much current TB vaccine research focuses on engineering live mycobacteria to interfere with phagosome biology and host intracellular pathways including apoptosis and autophagy, with candidates such as BCG Δzmp1, BCG ΔureC::hly, BCG::ESX-1^Mmar, Mtb ΔphoP ΔfadD26, Mtb ΔRD1 ΔpanCD and M. smegmatis Δesx-3::esx-3(Mtb) in the development pipeline. Correlates of protection in preclinical studies include increased central memory CD4⁺ T cells and recruitment of antigen-specific T cells to the lungs, with mucosal vaccination found to be superior to parenteral vaccination. Finally, recent studies suggest beneficial non-specific effects of BCG on immunity, which should be taken into account when considering these vaccines for BCG replacement.