Radiotherapy Combined with a Radiosensitizer for Bacillus Calmette-Guérin-unresponsive Non-muscle-invasive Carcinoma In Situ Bladder Cancer: An Open-label, Single-arm, Multicenter, Phase 2 European Organisation for Research and Treatment of Cancer Trial

Radical cystectomy with pelvic lymph node dissection and urinary diversion is the standard of care for patients with bacillus Calmette-Guérin (BCG)-unresponsive non-muscle-invasive bladder cancer (NMIBC). However, many patients are unwilling or unable to undergo such major surgery associated with high morbidity and a negative impact on quality of life. Chemoradiotherapy is an established treatment option for muscle-invasive bladder cancer. However, it has not been investigated adequately in NMIBC until now. The European Organisation for Research and Treatment of Cancer (EORTC) 2235 study (NCT06310369) is designed as a multicenter, prospective, international, phase 2 trial of moderate hypofractionated radiotherapy combined with a radiosensitizer in BCG-unresponsive NMIBC patients with carcinoma in situ (CIS) who are not eligible for or declined to undergo radical cystectomy. Patients who have received nadofaragene firadenovec or TAR-200 are eligible. The primary endpoint is the 6-mo complete response (CR) rate defined by the absence of CIS proven by a control biopsy of the bladder. The secondary endpoints include overall survival, progression-free survival, durability of CR, grade 3-4 adverse events rate, patients' quality of life, and organ preservation rate. PATIENT SUMMARY: Intravesical instillation of bacillus Calmette-Guérin is the standard treatment of non-muscle-invasive, also coined as superficial, bladder cancer. In case the cancer recurs, even superficially, there is no other proven treatment than a radical cystectomy-the surgical removal of the bladder. Although the surgical technique has improved dramatically over the past few years, it remains contraindicated in patients with severe comorbidities. In addition, because it affects the quality of life, patients may reject this option. This study will assess the efficacy of external beam radiotherapy, a robust alternative to surgery in muscle-invasive bladder cancer. Radiotherapy will be administered 5 d a week for 4 wk. It will be associated with a "radiosensitizer," an intravenous or oral drug, during the radiotherapy treatment. The study will measure the proportion of patients remaining recurrence free at 6 mo and thereafter. It will also evaluate the safety of the treatment and its impact on quality of life.

Cost-effectiveness analysis of different treatment modalities in BCG-unresponsive NMIBC

OBJECTIVE

Radical cystectomy (RC) is the standard of care (SOC) in BCG-unresponsive NMIBC and is associated with a significant health-related quality-of-life burden. Recently, promising results have been published on Gemcitabine/Docetaxel, Pembrolizumab, and Hyperthermic Intravesical Chemotherapy (HIVEC) as salvage therapy options trying to increase the rate of bladder preservation. Here, we performed a Cost-Effectiveness-Analysis of those treatment modalities.

PATIENTS AND METHODS

We developed a Markov model from a payer's perspective drawing on clinical data of single-arm trials testing intravesical gemcitabine/docetaxel and pembrolizumab in BCG-unresponsive NMIBC, as well as clinical data from patients receiving hyperthermic intravesical chemotherapy HIVEC (n = 29) as intravesical salvage chemotherapy at our uro-oncological centre in Cologne. Costs were simulated utilising a non-commercial diagnosis-related groups grouper, utilities were derived from comparable cost-effectiveness studies. We used a Monte Carlo simulation to identify the optimal treatment, comparing the incremental cost effectiveness ratios (ICERs) at a willingness-to-pay threshold of €50 000 (euro)/quality-adjusted life year (QALY).

RESULTS

Over a horizon of 10 years, gemcitabine/docetaxel, HIVEC, and pembrolizumab were associated with costs of €48 353, €64 438, and €204 580, as well as a gain of QALYs of 6.16, 6.48, and 6.00, resulting in an ICER of €26 482, €42 567, and €184 533 respectively, in comparison to RC with total costs of €21 871 and a gain of QALYs of 5.01. Monte Carlo simulation identified HIVEC as the treatment of choice under assumption of a WTP of <€50 000.

CONCLUSION

Considering a WTP of <€50 000/QALY, gemcitabine/docetaxel and HIVEC are highly cost-effective therapeutic options in BCG-refractory NMIBC, while RC remains the cheapest option. At its current price, pembrolizumab would only be cost-effective assuming a price reduction of at least 70%.

Standardization of the evaluation and surveillance of patients with BCG unresponsive high grade non-muscle invasive bladder cancer clinical trials

There are multiple ongoing and planned clinical trials that are evaluating novel therapies to treat patients with BCG-unresponsive high grade nonmuscle invasive bladder cancer (NMIBC). Importantly, there is considerable variation in surveillance strategies between these clinical trials, specifically with regards to the use of advanced imaging, enhanced cystoscopy, and mandatory biopsies, which could impact landmark efficacy assessments of investigational agents. To present guideline recommendations for the standardization of cystoscopic evaluation, surveillance, and efficacy assessments for patients with BCG-unresponsive NMIBC participating in clinical trials. On September 29, 2023 at the annual meeting of the International Bladder Cancer Network, a breakout session was convened, during which representatives from various disciplines discussed potential guidance statements with opportunity for discussion and comment. A set of statements regarding use of white light and enhanced cystoscopy were developed to help guide a pragmatic approach to surveillance and efficacy assessments of patients in clinical trials. The use of "for cause" and "mandatory" biopsies was also addressed. A standard approach to evaluation of patients within the context of clinical trials is necessary to accurately assess the efficacy of novel agents, especially within single arm trials that lack an appropriate comparator. Additionally, the utilization and timing of mandatory biopsies is critical, as these biopsies may impact both disease evaluations and the determination of duration of response.

A Phase 1b/2 Study of Atezolizumab with or Without Bacille Calmette-Guérin in Patients with High-risk Non-muscle-invasive Bladder Cancer

BACKGROUND

Bacille Calmette-Guérin (BCG) is the standard therapy after transurethral resection of bladder tumour for high-risk non-muscle-invasive bladder cancer (NMIBC). However, post-BCG recurrence/progression occurs frequently, and noncystectomy options are limited.

OBJECTIVE

To evaluate the safety and clinical activity of atezolizumab ± BCG in high-risk BCG-unresponsive NMIBC.

DESIGN, SETTING, AND PARTICIPANTS

This phase 1b/2 GU-123 study (NCT02792192) treated patients with BCG-unresponsive NMIBC who had carcinoma in situ with atezolizumab ± BCG.

INTERVENTION

Patients in cohorts 1A and 1B received atezolizumab 1200 mg IV q3w for ≤96 wk. Those in cohort 1B also received standard BCG induction (six weekly doses) and maintenance courses (three doses weekly starting at month 3) with optional maintenance at 6, 12, 18, 24, and 30 mo.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Coprimary endpoints were safety and 6-mo complete response (CR) rate. Secondary endpoints included 3-mo CR rate and duration of CR; 95% confidence intervals were calculated using the Clopper-Pearson method.

RESULTS AND LIMITATIONS

At data cut-off (September 29, 2020), 24 patients were enrolled (cohort 1A, n = 12; cohort 1B, n = 12), and the recommended BCG dose was 50 mg in cohort 1B. Four patients (33%) had adverse events (AEs) leading to BCG dose modification/interruption. Three patients (25%) in cohort 1A reported atezolizumab-related grade 3 AEs; cohort 1B had no atezolizumab- or BCG-related grade ≥3 AEs. No grade 4/5 AEs were reported. The 6-mo CR rate was 33% in cohort 1A (median duration of CR, 6.8 mo) and 42% in cohort 1B (median duration of CR, not reached [≥12 mo]). These results are limited by the small sample size of GU-123.

CONCLUSIONS

In this first report of the atezolizumab-BCG combination in NMIBC, atezolizumab ± BCG was well tolerated, with no new safety signals or treatment-related deaths. Preliminary results suggested clinically meaningful activity; the combination favoured a longer duration of response.

PATIENT SUMMARY

We studied atezolizumab with and without bacille Calmette-Guérin (BCG) to determine whether this combination was safe and had clinical activity in patients with high-risk noninvasive bladder cancer (high-grade bladder tumours that affect the outermost lining of the bladder wall) that has previously been treated with BCG and is still present or occurred again. Our results suggest that atezolizumab with or without BCG was generally safe and could be used to treat patients unresponsive to BCG.

Emerging treatment landscape of non-muscle invasive bladder cancer

INTRODUCTION

Non-muscle invasive bladder cancer (NMIBC) accounts for 70-75% of all bladder cancers and is a heterogeneous disease characterized by a wide spectrum of recurrences and progression. Adjuvant treatment for intermediate- and high-risk NMIBC is mainly represented by Bacillus Calmette Guerin (BCG). However, 20%-40% of patients develop disease recurrences or persistence following BCG treatment and are classified as "BCG unresponsive' (BCGu), thus representing a therapeutic challenge due to their worse prognosis and unavailability of effective intravesical treatments.

AREAS COVERED

We provide an overview of completed and ongoing clinical trials assessing the role of innovative immunological and target agents in patients with BCGu and BCG naive (BCGn) NMIBCs. New treatment options are emerging, demonstrating promising clinical activity, namely, pembrolizumab, atezolizumab, oportuzumab monatox, nadofaragene firadenovec, and N-803.

EXPERT OPINION

The increasing number of newer therapeutic agents for patients with NMIBC poses challenges regarding the choice of the most suited treatment option for each patient and the best treatment sequence, given their diverse mechanisms of action and varying degrees of activity. Tailored treatment approaches are advocated, based on a deeper comprehension of disease features, available therapies, patient's characteristics, and consequently, on the identification and validation of prognostic and predictive biomarkers.

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.

Checkpoint inhibitors in BCG-unresponsive nonmuscle invasive bladder cancer: can they help spare the bladder?

Intravesical BCG therapy has been for years, the standard of care in nonmuscle-invasive bladder cancer. But upon recurrence/relapse, radical cystectomy is imposed, due to the paucity of other therapeutic options. Immunotherapy has been revolutionizing cancer treatment, and its indications continue to broaden. It has been approved for the treatment of advanced urothelial cancer of the bladder, mainly as a second-line therapy. Its activity is being studied in nonmuscle-invasive bladder cancer that is not responsive to BCG; we herein report the trials investigating these checkpoint inhibitors (pembrolizumab, nivolumab, atezolizumab, durvalumab and avelumab) in this particular setting.

Adverse events of hyperthermic intravesical chemotherapy for non-muscle invasive bladder cancer patients

INTRODUCTION

Non-muscle invasive bladder cancer (NMIBC) is one of the most frequent neoplasms in Denmark. Treatment of high-risk NMIBC usually consists of transurethral resection of bladder (TUR-B) followed by intravesical Bacillus Calmette-Guérin (BCG) instillations. Unfortunately, some patients are BCG-unresponsive and will relapse over time. Radical cystectomy is the recommended salvage treatment following BCG-failure or BCG-intolerance. However, not all patients are candidates for surgery and thus, in need of other treatment. This study investigates the adverse events of Hyperthermic Intravesical Chemotherapy (HIVEC) treatment.

METHODS

Twenty-three high-risk NMIBC patients, who were BCG-unresponsive or had contraindications for BCG, received HIVEC with Mitomycin C. Prior to each instillation, patients were interviewed by a nurse, using a systematic questionnaire regarding the adverse events. Patients were followed with cytology and cystoscopy every fourth month. The primary outcome was adverse event related to the HIVEC treatment.

RESULTS

In general, the adverse events were mild to moderate and often self-limiting. The most common adverse events were urinary frequency (23.6%), incontinence (19.4%) and urinary tract pain (12.2%).

CONCLUSION

In the current study, we found that HIVEC was a well-tolerated treatment. HIVEC might be a feasible option for patients, who experienced BCG-failure or BCG-intolerance and could potentially postpone or avoid radical cystectomy.

New immunotherapy treatments in non-muscle invasive bladder cancer

Non-muscle invasive bladder cancer (NMIBC) is a highly heterogeneous disease that hides classes of patients who behave significantly differently under a favorable overall prognosis facade. Individual risk stratification and good decision making improve the patient outcomes. To date, radical cystectomy remains the treatment of choice in particularly aggressive subsets of disease, also due to the lack of proven alternative bladder-sparing strategies.Cancer immunotherapy, by inhibiting the PD-1/PD-L1axis, has shown durable efficacy in the treatment of advanced and metastatic unresectable urothelial carcinoma, and is studied with great interest in early disease settings. The updated data of the KEYNOTE-057 study have recently promoted the United States (US) Food and Drug Administration (FDA) approval of pembrolizumabin patients with CIS-containing BCG-unresponsive NMIBC. This significant step forward paves the way to a new window of therapeutic opportunities, while underlining new needs and questions to be addressed.

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.

How Should I Manage a Patient with Tumor Recurrence Despite Adequate Bacille Calmette-Guérin?

Intravesical immunotherapy with bacille Calmette-Guérin (BCG) vaccine is the main treatment for non-muscle-invasive bladder cancer (NMIBC), with proven effects on reducing recurrence, progression, and death from NMIBC. However, it is not effective in all patients, and recurrence after adequate BCG therapy can frequently lead to progression to more life-threatening disease. This point-counterpoint review considers how to treat a healthy 60-yr-old patient with T1 high-grade NMIBC fitting the new definition of BCG-unresponsive disease, that is, persistent high-grade disease at 6-12mo, despite an adequate course of induction and maintenance with BCG. PATIENT SUMMARY: When T1 high-grade non-muscle-invasive bladder cancer is persistent or recurs shortly after a full course of bacille Calmette-Guérin (BCG) plus maintenance, further BCG is not likely to work; this meets the new definition of a "BCG unresponsive" disease. For this situation, the safest (curative) option is removal of the bladder. If that is not an accepted alternative, then a clinical trial or combination intravesical chemotherapy or hyperchemotherapy may be another option.

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.

Current clinical trials in non-muscle invasive bladder cancer

BACKGROUND

The treatment options for non-muscle invasive bladder cancer (NMIBC) remain limited. Bacillus Calmette-Guerin (BCG) was the last major breakthrough in bladder cancer therapy almost 4 decades ago. There have been improvements in the understanding of immune therapies and cancer biology, leading to the development of novel agents. This has led to many clinical trials that are currently underway to find the next generation of therapies for NMIBC.

METHOD

We reviewed clinicaltrials.org and pubmed.gov to find the recently completed and ongoing clinical trials in NIMBC. Included in this review are clinical trials that are currently active and trials that were completed in and after 2014.

RESULT

Many trials with BCG-naive and BCG-unresponsive/recurrent/refractory/failure patients with NMIBC are either currently underway or have been recently completed. A wide variety of novel therapeutic agents are being investigated that range from cytotoxic agents to immunomodulatory agents to targeted molecular therapies. Other approaches include cancer vaccines, gene therapies, and chemoradiation potentiation agents. Novel drug-delivery methods are also being tested.

CONCLUSION

This comprehensive update of current trials provides researchers an overview of the current clinical trial landscape for patients with NMIBC.

An open label, single-arm, phase II multicenter study of the safety and efficacy of CG0070 oncolytic vector regimen in patients with BCG-unresponsive non-muscle-invasive bladder cancer: Interim results

OBJECTIVES

CG0070 is a replication-competent oncolytic adenovirus that targets bladder tumor cells through their defective retinoblastoma pathway. Prior reports of intravesical CG0070 have shown promising activity in patients with high-grade non-muscle invasive bladder cancer (NMIBC) who previously did not respond to bacillus Calmette-Guérin (BCG). However, limited accrual has hindered analysis of efficacy, particularly for pathologic subsets. We evaluated interim results of a phase II trial for intravesical CG0070 in patients with BCG-unresponsive NMIBC who refused cystectomy.

PATIENTS AND METHODS

At interim analysis (April 2017), 45 patients with residual high-grade Ta, T1, or carcinoma-in-situ (CIS) ± Ta/T1 had evaluable 6-month follow-up in this phase II single-arm multicenter trial (NCT02365818). All patients received at least 2 prior courses of intravesical therapy for CIS, with at least 1 being a course of BCG. Patients had either failed BCG induction therapy within 6 months or had been successfully treated with BCG with subsequent recurrence. Complete response (CR) at 6 months was defined as absence of disease on cytology, cystoscopy, and random biopsies.

RESULTS

Of 45 patients, there were 24 pure CIS, 8 CIS + Ta, 4 CIS + T1, 6 Ta, 3 T1. Overall 6-month CR (95% CI) was 47% (32%-62%). Considering 6-month CR for pathologic subsets, pure CIS was 58% (37%-78%), CIS ± Ta/T1 50% (33%-67%), and pure Ta/T1 33% (8%-70%). At 6 months, the single patient that progressed to muscle-invasive disease had Ta and T1 tumors at baseline. No patients with pure T1 had 6-month CR. Treatment-related adverse events (AEs) at 6 months were most commonly urinary bladder spasms (36%), hematuria (28%), dysuria (25%), and urgency (22%). Immunologic treatment-related AEs included flu-like symptoms (12%) and fatigue (6%). Grade III treatment-related AEs included dysuria (3%) and hypotension (1.5%). There were no Grade IV/V treatment-related AEs.

CONCLUSIONS

This phase II study demonstrates that intravesical CG0070 yielded an overall 47% CR rate at 6 months for all patients and 50% for patients with CIS, with an acceptable level of toxicity for patients with high-risk BCG-unresponsive NMIBC. There is a particularly strong response and limited progression in patients with pure CIS.