Definition and management of patients with bladder cancer who fail BCG therapy

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.

Sequential treatment with Bacillus Calmette-Güerin (BCG) and mitomycin C administered with Electromotive Drug Administration (EMDA) in patients with high-risk non-muscle invasive bladder cancer after BCG failure

BACKGROUND

Nowadays, there is no standard non-surgical treatment for patients with nonmuscle invasive bladder cancer (NMIBC) in whom Bacillus Calmette-Güerin (BCG) therapy has failed.

OBJECTIVES

To assess the clinical and oncological outcomes of sequential treatment with Bacillus Calmette-Guerin (BCG) and Mitomycin C (MMC) administered with Electromotive Drug Administration (EMDA) in patients with high-risk NMIBC who fail BCG immunotherapy.

MATERIAL AND METHODS

We retrospectively studied patients with NMIBC who failed BCG and received alternating BCG and Mitomycin C with EMDA between 2010 and 2020. Treatment schedule consisted in an induction therapy with 6 instillations (BCG, BCG, MMC + EMDA, BCG, BCG, MMC + EMDA) and a 1-year maintenance. Complete response (CR) was defined as the absence of high-grade (HG) recurrences during follow-up, and progression was defined as the occurrence of muscle invasive or metastatic disease. CR rate was estimated at 3, 6, 12, and 24 months. Progression rate and toxicity were also assessed.

RESULTS

Twenty-two patients were included with a median age of 73 years. Fifty percent of tumors were single, 90% were smaller than 1.5cm, 40% were GII (HG) and 40% were Ta. CR rate was 95.5%, 81% and 70% at 3 and 6 months, 12 months and 24 months, respectively. With a median follow-up of 28.8 months, 6 patients (27%) presented HG recurrence and only 1 patient (4.5%) progressed and ended in cystectomy. This patient died due to metastatic disease. Treatment was well tolerated and 22% of the patients presented adverse effects, being dysuria the most frequent one.

CONCLUSION

Sequential treatment with BCG and Mitomycin C with EMDA achieved good responses and low toxicity in selected patients who did not respond to BCG. Only 1 patient ended in cystectomy and died due to metastatic disease, therefore, cystectomy was avoided in most cases.

FimH confers mannose-targeting ability to Bacillus Calmette-Guerin for improved immunotherapy in bladder cancer

BACKGROUND

Bladder cancer is a common disease worldwide with most patients presenting with the non-muscle-invasive form (NMIBC) at initial diagnosis. Postoperational intravesical instillation of BCG is carried out for patients with high-risk disease to reduce tumor recurrence and progression to muscle invasive disease. However, BCG can also have side effects or be ineffective in some patients because it cannot enter the cancer cells. Thus, to improve the efficacy of BCG immunotherapy is the long-term pursuit of the bladder cancer field.

METHODS

To increase the adhesion of BCG to the urothelium we overexpressed FimH, a mannose binding protein naturally used by uropathogenic Escherichia coli to adhere to human urothelium, onto the surface of BCG. The adhesion/internalization ability of rBCG-S.FimH was examined in mouse bladder by fluorescence microscopy. Preclinical evaluation of antitumor efficacy was carried out in orthotopic mouse models of bladder cancer and in human peripheral blood mononuclear cells. Mechanistic studies were carried out using toll-like receptor 4 (TLR4) knockout mice. Immune cells and cytokines in the serum, tumor and lymph nodes were analyzed by flow cytometry, PCR, ELISA and ELISPOT.

RESULTS

rBCG-S.FimH exhibited markedly improved adhesion and more rapid internalization into urothelial cells than wild-type BCG, resulting in more potent antitumor activity in orthotopic murine models of bladder cancer. To our surprise, rBCG-S.FimH elicited a much more prominent Th1-biased immune response known to be positively correlated with BCG efficacy. Mechanistic studies using TLR4 knockout mouse showed that rBCG-S.FimH could induce enhanced dendritic cell activation and tumor antigen-specific immune response in a TLR4-dependent manner. Furthermore, human peripheral blood mononuclear cells stimulated by rBCG-S.FimH also showed better tumoricidal effects than those using wild-type BCG.

CONCLUSION

rBCG-S.FimH is a novel BCG strain with significantly improved efficacy against bladder cancer. Since intravesical BCG immunotherapy is the first-line treatment for NMIBC, which accounts for more than 70% of all bladder cancer cases, our results provide a compelling rationale for clinical development.

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.

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.

Immunotherapy: a new treatment paradigm in bladder cancer

PURPOSE OF REVIEW

T-cell checkpoint blockade has become a dynamic immunotherapy for bladder cancer. In 2016, atezolizumab, an immune checkpoint inhibitor, became the first new drug approved in metastatic urothelial carcinoma (mUC) in over 30 years. In 2017, nivolumab was also approved for the same indication. This overview of checkpoint inhibitors in clinical trials focuses on novel immunotherapy combinations, predictive biomarkers including mutational load and neoantigen identification, and an evaluation of the future of bladder cancer immunotherapy.

RECENT FINDINGS

Programed cell death protein 1/programed death-ligand 1 (PD-1/PD-L1) checkpoint inhibitors have achieved durable clinical responses in a subset of previously treated and treatment-naïve patients with mUC. The combination of PD-1 and cytotoxic T-lymphocyte antigen 4 (CTLA-4) has successfully improved response rates in multiple malignancies, and combination studies are underway in many tumor types, including bladder cancer, combining T-cell checkpoint blockade with other checkpoint agents and immunomodulatory therapies. Strong tumor responses to checkpoint blockade have been reported to be positively associated with expression of PD-L1 on tumor and tumor-infiltrating immune cells and with increased mutation-associated neoantigen load, which may lead to the development of predictive biomarkers.

SUMMARY

Recent clinical evidence suggests that mUC is susceptible to T-cell checkpoint blockade. A global effort is underway to achieve higher response rates and more durable remissions, accelerate the development of immunotherapies, employ combination therapies, and test novel immune targets.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Efficacy and safety of a new device for intravesical thermochemotherapy in non-grade 3 BCG recurrent NMIBC: a phase I-II study

PURPOSE

We report for the first time the activity and safety of Unithermia(®) (Elmedical Ltd, Hod-Hasharon, Israel), a novel device for administration of MMC-C with hyperthermia (HT), that employs conductive heating, in a series of non-grade 3 non-muscle-invasive bladder cancer (NMIBC) that failed Bacillus Calmette-Guerin (BCG).

METHODS

Patients with non-grade 3 NMIBC recurring after at least a full induction course of BCG were eligible for this phase I-II prospective single-arm study. Six weekly instillations with Unithermia(®) were scheduled following complete TUR. Primary end points were treatment safety and response rate (RR), and the latter defined as the absence of any unfavourable outcome at 12 months. Any grade 3 and/or muscle-invasive (T > 1) recurrence was considered disease progression. Kaplan-Meier estimation of the time to recurrence and progression, cancer-specific survival and overall survival was taken as secondary end points.

RESULTS

Thirty-four eligible patients entered the study between January 2009 and April 2011. RR was documented in 20/34 (59%). Among the 14/34 (41%) non-responders, four developed G3 disease, one developed carcinoma in situ, and one progressed to muscle-invasive bladder cancer, with an overall 18% progression rate at 1 year. At a median follow-up of 41 months, recurrence and progression rates were 35.3 and 23.5%, respectively. Toxicity did not go beyond grade 2 except in five cases.

CONCLUSIONS

Initial experience with MMC-HT with Unithermia(®) showed an interesting activity and safety profile in non-grade 3 NMIBC recurring after BCG, suggesting a role as second-line therapy in this selected subgroup of NMIBC.

Immunotherapy and Radiation - A New Combined Treatment Approach for Bladder Cancer?

Recently, immunotherapy with checkpoint inhibitors has been showing promise in clinical trials for stage IV bladder cancer. Herein, we review the literature regarding the role for radiation therapy, the role for immunotherapy, and the potential synergy of these treatments combined in bladder cancer. There is ample pre-clinical data in a number of different tumor models, coupled with a growing body of clinical evidence in melanoma and other malignancies to suggest combining radiation and immunotherapy could lead to substantial advances in treatment outcomes for bladder cancer. Yet, these data for bladder cancer remain at the pre-clinical stage, and further study is needed.

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

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

Surveillance and treatment of non-muscle-invasive bladder cancer in the USA

Seventy percent of newly diagnosed bladder cancers are classified as non-muscle-invasive bladder cancer (NMIBC) and are often associated with high rates of recurrence that require lifelong surveillance. Currently available treatment options for NMIBC are associated with toxicities that limit their use, and actual practice patterns vary depending upon physician and patient characteristics. In addition, bladder cancer has a high economic and humanistic burden in the United States (US) population and has been cited as one of the most costly cancers to treat. An unmet need exists for new treatment options associated with fewer complications, better patient compliance, and decreased healthcare costs. Increased prevention of recurrence through greater adherence to evidence-based guidelines and the development of novel therapies could therefore result in substantial savings to the healthcare system.

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

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

Radical cystectomy for BCG failure: has the timing improved in recent years?

OBJECTIVE

• To analyse if there is a trend in recent years towards performing radical cystectomy (RC) before muscle invasion or extravesical spread after failure of bacille Calmette-Guérin (BCG) for high grade Ta/T1 bladder cancer. Although BCG is indicated for prophylaxis after endoscopic tumour resection there is still a risk of progression.

PATIENTS AND METHODS

• A retrospective analysis of our RC database (1992-2008) was performed to identify patients who underwent RC after receiving BCG. • Relevant clinical and pathological data for the patients with clinical stage Ta, T1 and/or Tis at initial transurethral resection of bladder tumour were analysed. • Pathological stage and survival for patients undergoing RC from 2003 to 2007 (group 2) were compared with those for patients operated between 1992 and 2002 (group 1).

RESULTS

• A total of 152 patients were included (75 in group 2 and 77 in group 1). Both groups were similar in T-stage before BCG initiation, number of BCG cycles received and time interval to RC. • There was no change in the proportion of patients undergoing RC with ≥ pT2 bladder cancer in recent years (P= 0.5). • Fifty-two percent of group 2 and 43% of group 1 had ≥ pT2 BC. The 5-year survival was similar.

CONCLUSIONS

• Despite concerns about delay in performing RC for patients failing one or more courses of BCG we have not observed a trend towards a lower pathological stage for patients undergoing RC after BCG. • A high proportion of patients have muscle-invasive bladder cancer; more than 10% have lymph node metastasis.

Investigational therapies for non-muscle invasive bladder cancer

IMPORTANCE OF THE FIELD

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

AREAS COVERED IN THE REVIEW

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

WHAT THE READER WILL GAIN

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

TAKE HOME MESSAGE

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