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

Recent Advances in Drug Delivery Strategies for High-Risk BCG-Unresponsive Non-Muscle Invasive Bladder Cancer: A Brief Review from 2018 to 2024

High-risk BCG-unresponsive non-muscle invasive bladder cancer (NMIBC) is a condition that is typically treated with Bacillus Calmette-Guérin (BCG) therapy. Unfortunately, NMIBC is characterized by high recurrence, with a significant percentage of BCG patients ultimately requiring radical cystectomy. As a consequence, the development of effective new therapies to avoid RC has become a rapidly evolving field to address this unmet clinical need. To date, three biologics-Keytruda, Adstiladrin, and Anktiva-have been approved by the FDA, and multiple drug modalities, particularly gene therapies, have shown promising results in clinical trials. Advances in drug delivery strategies, such as targeted delivery, sustained release, and permeabilization of protective layers, are critical in overcoming the challenges posed by therapeutic intervention in bladder cancer. This review focuses on high-risk BCG-unresponsive NMIBC therapies that have been or are currently being investigated in clinical trials, offering a broad overview of the delivery system designs and up-to-date clinical outcomes that have been reported as of July 2024. It aims to inform the development of future drug delivery systems for second-line therapies in high-risk BCG-unresponsive NMIBC.

Bladder-sparing Therapy for Bacillus Calmette-Guérin-unresponsive Non-muscle-invasive Bladder Cancer: International Bladder Cancer Group Recommendations for Optimal Sequencing and Patient Selection

BACKGROUND AND OBJECTIVE

There has been a recent surge in the development of agents for bacillus Calmette-Guérin-unresponsive (BCG-U) non-muscle-invasive bladder cancer (NMIBC). Critical assessment of these agents and practical recommendations for optimal selection of patients and therapies are urgently needed, especially in the absence of randomized trials on bladder-sparing treatment (BST) options.

METHODS

A global committee of bladder cancer experts was assembled to develop recommendations on BST for BCG-U NMIBC. Working groups reviewed the literature and developed draft recommendations, which were then voted on by International Bladder Cancer Group (IBCG) members using a modified Delphi process. During a live meeting in August 2023, voting results and supporting evidence were presented, and recommendations were refined on the basis of meeting discussions. Final recommendations achieved >75% agreement during the meeting, and some were further refined via web conferences and e-mail discussions.

KEY FINDINGS AND LIMITATIONS

There is currently no single optimal agent for patients with BCG-U disease who seek to avoid radical cystectomy (RC). BST selection should be personalized, taking into account individual patient characteristics and preferences, tumor attributes, and efficacy/toxicity data for the agents available. For patients with BCG-U carcinoma in situ (CIS), gemcitabine/docetaxel (GEM/DOCE), nadofaragene firadenovec (NFF), and nogapendekin alfa inbakicept-pmln (NAI) + BCG are recommended; because of its systemic toxicity, pembrolizumab should only be offered after other options are exhausted. For patients with BCG-U papillary-only tumors, GEM/DOCE, NFF, NAI + BCG, single-agent chemotherapy, hyperthermic mitomycin C, and pembrolizumab are recommended. Given the modest efficacy of available options, clinical trial participation is encouraged. For unapproved agents with reported data, IBCG recommendations await the final results of pivotal trials.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The IBCG consensus recommendations provide practical guidance on BST for BCG-U NMIBC.

Efficacy and safety of tislelizumab plus bacillus-calmette guérin with or without chemotherapy as a bladder-sparing treatment for high-risk non-muscle-invasive bladder urothelial cancer: a real-world study

BACKGROUND

Despite adequate transurethral resection of the bladder tumor (TURBT) followed by intravesical bacillus-calmette guérin (BCG), high-risk non-muscle-invasive bladder cancer (HR-NMIBC) is associated with high rates of recurrence and progression. Immune checkpoint inhibitors can improve antitumor activity in bladder cancer, but relevant evidence in HR-NMIBC is limited. Thus, we evaluated the efficacy and safety of the tislelizumab-based combination regimen in HR-NMIBC.

METHODS

A retrospective study included 21 patients diagnosed with HR-NMIBC between July 2020 and September 2022. All patients underwent TURBT followed by combination regimens of tislelizumab plus BCG with or without gemcitabine/cisplatin (GC) chemotherapy. Clinical Data on demographics and characteristics, treatment information, outcomes, and safety were collected and analyzed.

RESULTS

Among the 21 patients with HR-NMIBC, the median age was 63 years (range 39-85), with the majority of patients with stage T1 (16/21, 76.19%). The median treatment of tislelizumab was 5 cycles (range 1-12) and the median number of BCG instillations was 12 times (range 2-19). Of the 21 patients, 15 (71.43%) received combination chemotherapy with GC, with a median treatment of 2 cycles (range 0-7); others did not. Overall, after the median follow-up of 25 months (range 7-31), the estimated 2-year bladder recurrence-free survival rate was 78.64% (95% confidence intervals [CIs], 50.79-91.83%), 2-year cystectomy-free survival rate was 83.00% (95% CI 53.53-94.59%), and 2-year disease-free survival rate was 73.39% (95% CI 46.14-88.36%). Sixteen stage T1 patients achieved a distant metastasis-free survival rate of 95.45% (95% CI 71.87-99.34%) at 2 years. Fourteen (66.67%) patients experienced at least one treatment related-AEs (TRAEs), with 9.52% (2/21) of grade 3-4. Grade ≥ 3 TRAEs were hypophysitis (1/21, 4.76%) and myasthenia (1/21, 4.76%). No treatment-related deaths were observed.

CONCLUSIONS

The study demonstrated promising clinical benefits and a manageable safety profile of tislelizumab-based combination regimen as a bladder-sparing treatment of HR-NMIBC.

The combination of immune checkpoint inhibitors and antibody-drug conjugates in the treatment of urogenital tumors: a review insights from phase 2 and 3 studies

With the high incidence of urogenital tumors worldwide, urinary system tumors are among the top 10 most common tumors in men, with prostate cancer ranking first and bladder cancer fourth. Patients with resistant urogenital tumors often have poor prognosis. In recent years, researchers have discovered numerous specific cancer antigens, which has led to the development of several new anti-cancer drugs. Using protein analysis techniques, researchers developed immune checkpoint inhibitors (ICIs) and antibody-conjugated drugs (ADCs) for the treatment of advanced urogenital tumors. However, tumor resistance often leads to the failure of monotherapy. Therefore, clinical trials of the combination of ICIs and ADCs have been carried out in numerous centers around the world. This article reviewed phase 2 and 3 clinical studies of ICIs, ADCs, and their combination in the treatment of urogenital tumors to highlight safe and effective methods for selecting individualized therapeutic strategies for patients. ICIs activate the immune system, whereas ADCs link monoclonal antibodies to toxins, which can achieve a synergistic effect when the two drugs are combined. This synergistic effect provides multiple advantages for the treatment of urogenital tumors.

Novel Delivery Systems and Pharmacotherapeutic Approaches for the Treatment of Non-muscle-invasive Bladder Cancer

BACKGROUND AND OBJECTIVE

Therapeutic options for patients with non-muscle-invasive bladder cancer (NMIBC) have traditionally been limited to intravesical immunotherapy or chemotherapy. A considerable number of new options have been investigated in recent years. Our aim was to review the efficacy and toxicity of novel therapeutic options (results already reported or currently under investigation) for patients with NMIBC.

METHODS

We assessed the efficacy of various novel therapeutic options by examining key endpoints in diverse settings, including recurrence, progression, overall survival, disease-specific survival, and complete response. We identified the principal advantages and limitations for each option. Safety was predominantly evaluated as the incidence of grade ≥3 adverse events. Our investigation focused on evidence from scientific articles and congress abstracts published in English within the past 5 yr.

KEY FINDINGS AND LIMITATIONS

To date, pembrolizumab, nadofaragene firadenovec, and the combination of BCG with N-803 have received US Food and Drug administration approval for the treatment of BCG-unresponsive carcinoma in situ of the bladder (with or without papillary tumours). Five phase 3 trials are recruiting BCG-naïve patients with high-risk NMIBC. There is increasing interest in an ablative rather than an adjuvant approach for patients with intermediate-risk NMIBC.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Novel drugs and device-assisted drug delivery systems are on the verge of changing the treatment of NMIBC. Novel intravesical options seem to have the same efficacy with fewer adverse events in comparison to systemic therapies.

PATIENT SUMMARY

We reviewed new therapy options for non-muscle-invasive bladder cancer. Two agents (pembrolizumab and nadofaragene firadenovec) have been approved to date. Ongoing trials are assessing direct delivery of drugs in solution into the bladder. This route seems to have similar efficacy and fewer side effects than intravenous immunotherapy.

Breaking Barriers: Modulation of Tumor Microenvironment to Enhance Bacillus Calmette-Guérin Immunotherapy of Bladder Cancer

The clinical management of bladder cancer continues to present significant challenges. Bacillus Calmette-Guérin (BCG) immunotherapy remains the gold standard of treatment for non-muscle invasive bladder cancer (NMIBC), but many patients develop recurrence and progression to muscle-invasive disease (MIBC), which is resistant to BCG. This review focuses on the immune mechanisms mobilized by BCG in bladder cancer tumor microenvironments (TME), mechanisms of BCG resistance, the dual role of the BCG-triggered NFkB/TNFα/PGE2 axis in the regulation of anti-tumor and tumor-promoting aspects of inflammation, and emerging strategies to modulate their balance. A better understanding of BCG resistance will help develop new treatments and predictive biomarkers, paving the way for improved clinical outcomes in bladder cancer patients.

Treatment patterns and prognosis in patients with Bacillus Calmette-Guérin-exposed high-risk non-muscle invasive bladder cancer: a real-world data analysis

PURPOSE

The International Bladder Cancer Group designated the subgroup that is resistant to Bacillus Calmette-Guérin (BCG) but does not meet the criteria for BCG-unresponsive NMIBC as "BCG-exposed high-risk NMIBC" to guide optimal trial design. We aimed to investigate the treatment patterns and prognoses of patients with BCG-exposed NMIBC.

METHODS

We conducted a retrospective chart review of 3283 patients who received intravesical BCG therapy for NMIBC at 14 participating institutions between January 2000 and December 2019. Patients meeting the criteria for BCG-exposed and BCG-unresponsive NMIBC, as defined by the Food and Drug Administration and International Bladder Cancer Group, were selected. To compare treatment patterns and outcomes, high-risk recurrence occurring more than 24 months after the last dose of BCG was defined as "BCG-treated NMIBC." In addition, we compared prognoses between BCG rechallenge and early cystectomy in patients with BCG-exposed NMIBC.

RESULTS

Of 3283 patients, 108 (3.3%), 150 (4.6%), and 391 (11.9%) were classified as having BCG-exposed, unresponsive, and treated NMIBC, respectively. BCG-exposed NMIBC demonstrated intermediate survival curves for intravesical recurrence-free and progression-free survival, falling between those of BCG-unresponsive and treated NMIBC. Among patients with BCG-exposed NMIBC, 48 (44.4%) received BCG rechallenge, which was the most commonly performed treatment, and 19 (17.6%) underwent early cystectomy. No significant differences were observed between BCG rechallenge and early cystectomy in patients with BCG-exposed NMIBC.

CONCLUSIONS

The newly proposed definition of BCG-exposed NMIBC may serve as a valuable disease subgroup for distinguishing significant gray areas, except in cases of BCG-unresponsive NMIBC.

Bladder sparing by short-course radiotherapy combined with toripalimab in high-risk/extremely high-risk non-muscle invasive bladder cancer (HOPE-04): study protocol for a single-arm, prospective, phase II trial

INTRODUCTION

Radical cystectomy remains the standard treatment for intravesical Bacille Calmette-Guerin (BCG) unresponsive non-muscle invasive bladder cancer (NMIBC) because potential bladder-preserving therapies are not well established. Combination of radiotherapy with programmed death-1 (PD-1) antibody may offer an optional bladder preservation treatment for high-risk/extremely high risk NMIBC. Hence, the current study aims to investigate the safety and efficacy of short-course radiotherapy (5×5 Gy) and toripalimab (PD-1 antibody) as a novel bladder sparing treatment in this population.

METHODS AND ANALYSIS

HOPE-04 is an open-label, single-arm, phase II study, designed to evaluate the safety and efficacy of short-course radiotherapy and toripalimab in patients with high-risk/extremely high risk NMIBC. Fifty-five patients with pathological and imaging diagnosed NMIBC with or without BCG treatment will be recruited. Radiotherapy of 5×5 Gy will be given to the whole bladder followed by a focal tumour bed boost and concomitant administration of toripalimab of 240 mg intravenous infusion every 21 days for 12 cycles (about 1 year). The primary endpoints are disease-free survival and safety. The secondary endpoint is overall survival. Additional indicators include implementation rate of salvage surgery and quality of life.

ETHICS AND DISSEMINATION

This trial has been approved by the Ethics Committee of West China Hospital, Sichuan University. Trial findings will be disseminated via peer reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

Chinese Ethics Committee of Registering Clinical Trials (ChiCTR2200059970).

Integrating novel immunotherapeutic approaches in organ-preserving therapies for bladder cancer

Bladder cancer (BC) is a prevalent malignancy with significant morbidity and mortality. Over the years, the landscape of bladder cancer treatment has witnessed notable advancements, particularly in the realm of immunotherapy. Immunotherapy has emerged as a promising adjunct to organ-preserving approaches, harnessing the immune system's potential to target and eliminate cancer cells. Organ preservation strategies offer viable alternatives to radical cystectomy to avoid the morbidities associated with radical surgery, as well as to respond to the needs of patients unfit for or who have refused surgery. However, the challenge lies in achieving durable disease control while minimizing treatment-related toxicities. This review highlights the significance of immune checkpoint inhibitors, such as anti-programmed cell death 1 (PD-1)/programmed cell death 1 ligand 1 (PD-L1) antibodies, in the treatment of localized bladder cancer. The clinical efficacy of immune checkpoint inhibitors, as both neoadjuvant and adjuvant therapies in combination with radiation or chemotherapy, is discussed. Moreover, the potential of immunotherapies beyond immune checkpoint inhibition, including combinations with bacillus Calmette-Guérin (BCG) instillations and/or investigational gene therapies, is explored. Furthermore, the predictive value of the tumour immune microenvironment for the success of these strategies is examined. Understanding the complex interplay between tumour immunity and therapeutic interventions can aid in identifying predictive biomarkers and tailoring personalized treatment strategies. Further research and clinical trials are warranted to optimize the use of immunotherapy in conjunction with organ-preserving therapies, potentially leading to enhanced patient outcomes and quality of life.

Optimizing outcomes for high-risk, non-muscle-invasive bladder cancer: The evolving role of PD-(L)1 inhibition

Transurethral resection of bladder tumor followed by intravesical Bacillus Calmette-Guérin (BCG) is the standard of care in high-risk, non-muscle-invasive bladder cancer (NMIBC). Although many patients respond, recurrence and progression are common. In addition, patients may be unable to receive induction + maintenance due to intolerance or supply issues. Therefore, alternative treatment options are urgently required. Programmed cell death (ligand) 1 (PD-[L]1) inhibitors show clinical benefit in phase 1/2 trials in BCG-unresponsive NMIBC patients. This review presents the status of PD-(L)1 inhibition in high-risk NMIBC and discusses future directions. PubMed and Google scholar were searched for articles relating to NMIBC immunotherapy and ClinicalTrials.gov for planned and ongoing clinical trials. Preclinical and early clinical studies show that BCG upregulates PD-L1 expression in bladder cancer cells and, when combined with a PD-(L)1 inhibitor, a potent antitumor response is activated. Based on this mechanism, several PD-(L)1 inhibitors are in phase 3 trials in BCG-naïve, high-risk NMIBC in combination with BCG. Whereas PD-(L)1 inhibitors are well characterized in patients with advanced malignancies, the impact of immune-related adverse events (irAE) on the benefit/risk ratio in NMIBC should be determined. Alternative routes to intravenous administration, like subcutaneous and intravesical administration, may facilitate adherence and access. The outcomes of combination of PD-(L)1 inhibitors and BCG in NMIBC are highly anticipated. There will be a need to address treatment resources, optimal management of irAEs and education and training related to use of this therapy in clinical practice.

Immune Checkpoint Inhibitor Toxicity Management in Non-muscle-invasive Bladder Cancer: What Urologists Need To Know

Immune checkpoint inhibitors (ICIs) have emerged as a treatment option for non-muscle-invasive bladder cancer. Urologists need to be aware of the indications for ICI treatment in this setting and the systemic toxicities associated with these agents. We provide a brief overview of the most common treatment-related adverse events reported in the literature and summarize guidelines for their management. PATIENT SUMMARY: Immunotherapy is now being used as a treatment option for bladder cancer that does not invade the bladder muscle. Urologists need to become comfortable in recognizing and managing adverse effects associated with immunotherapy drugs.