Intravesical Gene Therapy

An evaluation of nadofaragene firadenovec-vncg for the treatment of high-risk BCG-unresponsive non-muscle-invasive bladder cancer

INTRODUCTION

BCG-unresponsive non-muscle invasive bladder cancer (NMIBC) represent a significant therapeutic challenge in the treatment of bladder cancer. Nadofaragene firadenovec, represents a breakthrough in this area, offering a novel approach for the treatment of BCG-unresponsive NMIBC.

AREAS COVERED

This overview explores the historical development of nadofaragene firadenovec, assessing its efficacy and safety, and discusses future NMIBC therapy directions.

EXPERT OPINION

Patients with high grade NMIBC who are BCG unresponsive will have a growing number of treatment alternatives to bladder removal. Nadofaragene firadenovec offers good short-term efficacy but lacks significant durability for most patients. Its strengths include ease of administration and low risk of adverse events. This will need to balance with risk of progression and cost. Furthermore, the likely approval of other agents will require consideration of which therapy to use and for which patient. The need for biomarkers to tailor treatment choices to individual patient needs is becoming more critical. The treatment field is rapidly advancing, with several Phase 3 single-arm trials underway, indicating a potential broader range of treatment options for NMIBC. Further research will be necessary to determine the optimal choice for patients.

Mechanism of action of nadofaragene firadenovec-vncg

Effective bladder-preserving therapeutic options are needed for patients with bacillus Calmette-Guérin unresponsive non-muscle-invasive bladder cancer. Nadofaragene firadenovec-vncg (Adstiladrin®) was approved by the US Food and Drug Administration as the first gene therapy in urology and the first intravesical gene therapy indicated for the treatment of adult patients with high-risk bacillus Calmette-Guérin-unresponsive non-muscle-invasive bladder cancer with carcinoma in situ with or without papillary tumors. The proposed mechanism of action underlying nadofaragene firadenovec efficacy is likely due to the pleiotropic nature of interferon-α and its direct and indirect antitumor activities. Direct activities include cell death and the mediation of an antiangiogenic effect, and indirect activities are those initiated through immunomodulation of the innate and adaptive immune responses. The sustained expression of interferon-α that results from this treatment modality contributes to a durable response. This review provides insight into potential mechanisms of action underlying nadofaragene firadenovec efficacy.

Healthcare Resource Utilization and Cost Burden of BCG-Treated Non-Muscle Invasive Bladder Cancer Patients in Germany: A Retrospective Claims Analysis

Background

Intermediate and high-risk non-muscle-invasive bladder cancer (NMIBC) is typically managed with transurethral resection of the bladder tumour (TURBT) followed by intravesical Bacillus Calmette-Guérin (BCG) immunotherapy; however, NMIBC patients can become refractory or unresponsive to BCG treatment, and/or progress to muscle-invasive bladder cancer (MIBC). Healthcare resource utilization (HCRU) and costs in these patient populations are high.

Methods

A retrospective longitudinal cohort design of adult (≥18 years) patients with bladder cancer and BCG treatment (01/01/2012-31/12/2017) was conducted using data from a representative subset of the German statutory health insurance database. During the follow-up period after last BCG, patients were categorized into subgroups of No further NMIBC treatment, Continuous treatment for NMIBC, or MIBC evidence; HCRU and costs were tabulated for each subgroup and for the entire cohort.

Results

A total of 1049 patients met the study inclusion criteria (mean age, 70.9 years; 84.8% male). Across the different subgroups, patients showing MIBC evidence had more than two times higher hospitalization rates compared to the other subgroups. Overall, the entire BCG-treated cohort's total direct medical cost including hospitalizations, outpatient care and drugs was €33.9 million and €9250 per patient-year. Cost for patients with MIBC evidence was much higher, at €17,983 per patient-year, than patients with No further NMIBC treatment (€6617) and patients with Continuous treatment for NMIBC (€7786). Across the subgroups, hospitalization was the largest driver of cost and contributed the most to cost for those with MIBC evidence.

Conclusion

The overall cost burden of this BCG-treated cohort of 1049 patients is high (€38 million whereof 4.1 million are indirect costs) over a mean follow-up of 3.9 years; economic burden is especially substantial for patients who fail BCG treatment and those who progress.

Nadofaragene Firadenovec: First Approval

Nadofaragene firadenovec (nadofaragene firadenovec-vncg; Adstiladrin^®) is a non-replicating adenoviral vector-based gene therapy developed by Ferring Pharmaceuticals for the treatment of high-risk Bacillus Calmette-Guérin (BCG)-unresponsive non-muscle invasive bladder cancer (NMIBC). Nadofaragene firadenovec constitutes vector DNA that encodes for interferon (IFN)-α2b and is the first approved gene therapy in bladder cancer. The production of IFN-α2b by transfected urothelial cells is associated with anticancer activity, including immunostimulatory, antiangiogenic and apoptotic effects. In December 2022, nadofaragene firadenovec received its first global approval in the USA for the treatment of high-risk BCG-unresponsive NMIBC with carcinoma in situ (CIS) with or without papillary tumours in adults. This article summarizes the milestones in the development of nadofaragene firadenovec leading to this first approval for this indication.

Novel intravesical therapeutics in the treatment of non-muscle invasive bladder cancer: Horizon scanning

Introduction

Non-muscle-invasive bladder cancer (NMIBC) is a common and heterogeneous disease; many patients develop recurrent or progress to muscle-invasive disease. Intravesical drug therapy is a pillar in the current management of NMIBC; notwithstanding, Mitomycin C (MMC) and Bacillus Calmette-Guérin (BCG) have numerous limitations including international supply issues, and local and systemic toxicity. Here we review novel intravesical therapeutic options and drug delivery devices with potential for clinical use in the treatment of NMIBC.

Methods

PubMed, ClinicalTrials.gov and Cochrane Library searches were undertaken. Systematic reviews, meta-analyses, randomised controlled trials, single-arm clinical trials and national/international conference proceedings were included.

Results

Novel intravesical drugs, including chemotherapeutic agents, immune checkpoint inhibitors, monoclonal antibodies and gene therapies, have demonstrated varying efficacy in the treatment of NMIBC. Current evidence for the majority of treatments is mostly limited to single-arm trials in patients with recurrent NMIBC. Various novel methods of drug delivery have also been investigated, with encouraging preliminary results supporting the intravesical delivery of hyperthermic MMC and MMC hydrogel formulations.

Conclusions

Novel therapeutic agents and drug delivery systems will be important in the future intravesical management of NMIBC. As our understanding of the molecular diversity of NMIBC develops, molecular subtyping will become fundamental in the personalisation of intravesical treatments. Further randomised studies are urgently required to investigate the efficacy of novel intravesical treatments and novel regimens, in comparison to current standards-of-care, particularly in the context of international BCG shortages.

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.

Clinical therapies and nano drug delivery systems for urinary bladder cancer

Bladder cancer is the 10^th most commonly occurring malignancy worldwide with a 75% of 5-year survival rate, while it ranks 13^th among the deaths occurring due to cancer. The majority of bladder cancer cases are diagnosed at an early stage and 70% are of non-invasive grade. However, 70% of these cases develop chemoresistance and progress to the muscle invasive stage. Conventional chemotherapy treatments are unsuccessful in curbing chemoresistance, bladder cancer progression while having an adverse side effect, which is mainly due to off-target drug distribution. Therefore, new drug delivery strategies, new therapeutics and therapies or their combination are being explored to develop better treatments. In this regard, nanotechnology has shown promise in the targeted delivery of therapeutics to bladder cancer cells. This review discusses the recent discovery of new therapeutics (chemotherapeutics, immunotherapeutic, and gene therapies), recent developments in the delivery of therapeutics using nano drug delivery systems, and the combination treatments with FDA-approved therapies, i.e., hyperthermia and photodynamic therapy. We also discussed the potential of other novel drug delivery systems that are minimally explored in bladder cancer. Lastly, we discussed the clinical status of therapeutics and therapies for bladder cancer. Overall, this review can provide a summary of available treatments for bladder cancer, and also provide opportunities for further development of drug delivery systems for better management of bladder cancer.