Efficacy of Intravesical Nadofaragene Firadenovec for Patients With Bacillus Calmette-Guérin-Unresponsive Nonmuscle-Invasive Bladder Cancer: 5-Year Follow-Up From a Phase 3 Trial.

PURPOSE: Nadofaragene firadenovec-vncg is a nonreplicating adenoviral vector-based gene therapy for bacillus Calmette-Guérin (BCG)-unresponsive carcinoma in situ (CIS) with/without high-grade Ta/T1. We report outcomes following 5 years of planned follow-up. MATERIALS AND METHODS: This open-label phase 3 trial (NCT02773849) enrolled patients with BCG-unresponsive nonmuscle-invasive bladder cancer in 2 cohorts: CIS ± Ta/T1 (CIS; n = 107) and Ta/T1 without CIS (Ta/T1 cohort; n = 50). Patients received 75 mL (3 × 1011 vp/mL) nadofaragene firadenovec intravesically once every 3 months with cystoscopy and cytology assessments, with continued treatment offered to those remaining high grade recurrence-free (HGRF). RESULTS: One hundred fifty-seven patients were enrolled from 33 US sites (n = 151 included in efficacy analyses). Median follow-up was 50.8 months (interquartile range 39.1-60.0), with 27% receiving ≥ 5 instillations and 7.6% receiving treatment for ≥ 57 months. Of patients with CIS 5.8% (95% CI 2.2-12.2) were HGRF at month 57, and 15% (95% CI 6.1-27.8) of patients with high-grade Ta/T1 were HGRF at month 57. Kaplan-Meier-estimated HGRF survival at 57 months was 13% (95% CI 6.9-21.5) and 33% (95% CI 19.5-46.6) in the CIS and Ta/T1 cohorts, respectively. Cystectomy-free survival at month 60 was 49% (95% CI 40.0-57.1): 43% (95% CI 32.2-53.7) in the CIS cohort and 59% (95% CI 43.1-71.4) in the Ta/T1 cohort. Overall survival at 60 months was 80% (71.0, 86.0): 76% (64.6-84.5) and 86% (70.9-93.5) in the CIS and Ta/T1 cohorts, respectively. Only 5 patients (4 with CIS and 1 with Ta/T1) experienced clinical progression to muscle-invasive disease. CONCLUSIONS: At 60 months, nadofaragene firadenovec-vncg allowed bladder preservation in nearly half of the patients and proved to be a safe option for BCG-unresponsive nonmuscle-invasive bladder cancer.

Lentiviral interferon: A novel method for gene therapy in bladder cancer.

Interferon alpha (IFNα) gene therapy is emerging as a new treatment option for patients with non-muscle invasive bladder cancer (NMIBC). Adenoviral vectors expressing IFNα have shown clinical efficacy treating bacillus Calmette-Guerin (BCG)-unresponsive bladder cancer (BLCA). However, transient transgene expression and adenoviral immunogenicity may limit therapeutic activity. Lentiviral vectors can achieve stable transgene expression and are less immunogenic. In this study, we evaluated lentiviral vectors expressing murine IFNα (LV-IFNα) and demonstrate IFNα expression by transduced murine BLCA cell lines, bladder urothelium, and within the urine following intravesical instillation. Murine BLCA cell lines (MB49 and UPPL1541) were sensitive to IFN-mediated cell death after LV-IFNα, whereas BBN975 was inherently resistant. Upregulation of interleukin-6 (IL-6) predicted sensitivity to IFN-mediated cell death mediated by caspase signaling, which when inhibited abrogated IFN-mediated cell killing. Intravesical therapy with LV-IFNα/Syn3 in a syngeneic BLCA model significantly improved survival, and molecular analysis of treated tumors revealed upregulation of apoptotic and immune-cell-mediated death pathways. In particular, biomarker discovery analysis identified three clinically actionable targets, PD-L1, epidermal growth factor receptor (EGFR), and ALDHA1A, in murine tumors treated with LV-IFNα/Syn3. Our findings warrant the comparison of adenoviral and LV-IFNα and the study of novel combination strategies with IFNα gene therapy for the BLCA treatment.

Antiadenovirus Antibodies Predict Response Durability to Nadofaragene Firadenovec Therapy in BCG-unresponsive Non-muscle-invasive Bladder Cancer: Secondary Analysis of a Phase 3 Clinical Trial.

A recent phase 3 trial of intravesical nadofaragene firadenovec reported a promising complete response rate for patients with bacillus Calmette-Guérin-unresponsive non-muscle-invasive bladder cancer. This study examined the ability of antiadenovirus antibody levels to predict the durability of therapeutic response to nadofaragene firadenovec. A standardized and validated quantitative assay was used to prospectively assess baseline and post-treatment serum antibody levels among 91 patients from the phase 3 trial, of whom 47 (52%) were high-grade recurrence free at 12 mo (responders). While baseline titers did not predict treatment response, 3-mo titer >800 was associated with a higher likelihood of durable response (p = 0.026). Peak post-treatment titers >800 were noted in 42 (89%) responders versus 26 (59%) nonresponders (p = 0.001; assay sensitivity, 89%; negative predictive value, 78%). Moreover, 22 (47%) responders compared with eight (18%) nonresponders had a combination of peak post-treatment titers >800 and peak antibody fold change >8 (p = 0.004; assay specificity, 82%; positive predictive value, 73%). A majority of responders continued to have post-treatment antibody titers >800 after the first 6 mo of therapy. In conclusion, serum antiadenovirus antibody quantification may serve as a novel predictive marker for nadofaragene firadenovec response durability. Future studies will focus on large-scale validation and clinical utility of the assay. PATIENT SUMMARY: This study reports on a planned secondary analysis of a phase 3 multicenter clinical trial that established the benefit of nadofaragene firadenovec, a novel intravesical gene therapeutic, for the treatment of patients with bacillus Calmette-Guérin (BCG)-unresponsive high-risk non-muscle-invasive bladder cancer. Prospective assessment of serum anti-human adenovirus type-5 antibody levels of patients in this trial indicated that a combination of post-treatment titers and fold change from baseline can predict treatment efficacy. While this merits additional validation, our findings suggest that serum antiadenovirus antibody levels can serve as an important predictive marker for the durability of therapeutic response to nadofaragene firadenovec.

Intravesical nadofaragene firadenovec gene therapy for BCG-unresponsive non-muscle-invasive bladder cancer: a single-arm, open-label, repeat-dose clinical trial.

BACKGROUND: BCG is the most effective therapy for high-risk non-muscle-invasive bladder cancer. Nadofaragene firadenovec (also known as rAd-IFNa/Syn3) is a replication-deficient recombinant adenovirus that delivers human interferon alfa-2b cDNA into the bladder epithelium, and a novel intravesical therapy for BCG-unresponsive non-muscle-invasive bladder cancer. We aimed to evaluate its efficacy in patients with BCG-unresponsive non-muscle-invasive bladder cancer. METHODS: In this phase 3, multicentre, open-label, repeat-dose study done in 33 centres (hospitals and clinics) in the USA, we recruited patients aged 18 years or older, with BCG-unresponsive non-muscle-invasive bladder cancer and an Eastern Cooperative Oncology Group status of 2 or less. Patients were excluded if they had upper urinary tract disease, urothelial carcinoma within the prostatic urethra, lymphovascular invasion, micropapillary disease, or hydronephrosis. Eligible patients received a single intravesical 75 mL dose of nadofaragene firadenovec (3 × 1011 viral particles per mL). Repeat dosing at months 3, 6, and 9 was done in the absence of high-grade recurrence. The primary endpoint was complete response at any time in patients with carcinoma in situ (with or without a high-grade Ta or T1 tumour). The null hypothesis specified a complete response rate of less than 27% in this cohort. Efficacy analyses were done on the per-protocol population, to include only patients strictly meeting the BCG-unresponsive definition. Safety analyses were done in all patients who received at least one dose of treatment. The study is ongoing, with a planned 4-year treatment and monitoring phase. This study is registered with ClinicalTrials.gov, NCT02773849. FINDINGS: Between Sept 19, 2016, and May 24, 2019, 198 patients were assessed for eligibility. 41 patients were excluded, and 157 were enrolled and received at least one dose of the study drug. Six patients did not meet the definition of BCG-unresponsive non-muscle-invasive bladder cancer and were therefore excluded from efficacy analyses; the remaining 151 patients were included in the per-protocol efficacy analyses. 55 (53·4%) of 103 patients with carcinoma in situ (with or without a high-grade Ta or T1 tumour) had a complete response within 3 months of the first dose and this response was maintained in 25 (45·5%) of 55 patients at 12 months. Micturition urgency was the most common grade 3-4 study drug-related adverse event (two [1%] of 157 patients, both grade 3), and there were no treatment-related deaths. INTERPRETATION: Intravesical nadofaragene firadenovec was efficacious, with a favourable benefit:risk ratio, in patients with BCG-unresponsive non-muscle-invasive bladder cancer. This represents a novel treatment option in a therapeutically challenging disease state. FUNDING: FKD Therapies Oy.

Transcriptomics uncovers substantial variability associated with alterations in manufacturing processes of macrophage cell therapy products.

Gene expression plasticity is central for macrophages' timely responses to cues from the microenvironment permitting phenotypic adaptation from pro-inflammatory (M1) to wound healing and tissue-regenerative (M2, with several subclasses). Regulatory macrophages are a distinct macrophage type, possessing immunoregulatory, anti-inflammatory, and angiogenic properties. Due to these features, regulatory macrophages are considered as a potential cell therapy product to treat clinical conditions, e.g., non-healing diabetic foot ulcers. In this study we characterized two differently manufactured clinically relevant regulatory macrophages, programmable cells of monocytic origin and comparator macrophages (M1, M2a and M0) using flow-cytometry, RT-qPCR, phagocytosis and secretome measurements, and RNA-Seq. We demonstrate that conventional phenotyping had a limited potential to discriminate different types of macrophages which was ameliorated when global transcriptome characterization by RNA-Seq was employed. Using this approach we confirmed that macrophage manufacturing processes can result in a highly reproducible cell phenotype. At the same time, minor changes introduced in manufacturing resulted in phenotypically and functionally distinct regulatory macrophage types. Additionally, we have identified a novel constellation of process specific biomarkers, which will support further clinical product development.

Development of Large-Scale Downstream Processing for Lentiviral Vectors.

The interest in lentiviral vectors (LVs) has increased prominently for gene therapy applications, but few have reached the later stages of clinical trials. The main challenge has remained in scaling up the manufacturing process for the fragile vector to obtain high titers for in vivo usage. We have previously scaled up the LV production to iCELLis 500, being able to produce up to 180 L of harvest material in one run with perfusion. The following challenge considers the purification and concentration of the product to meet titer and purity requirements for clinical use. We have developed a downstream process, beginning with clarification, buffer exchange, and concentration, by tangential flow filtration. This is followed by a purification step using single membrane-based anion exchange chromatography and final formulation with tangential flow filtration. Different materials and conditions were compared to optimize the process, especially for the chromatography step that has been the bottleneck in lentiviral vector purification scale-up. The final infectious titer of the lentiviral vector product manufactured using the optimized scale-up process was determined to be 1.97 × 109 transducing units (TU)/mL, which can be considered as a high titer for lentiviral vectors.

Preclinical Proof-of-Concept, Analytical Development, and Commercial Scale Production of Lentiviral Vector in Adherent Cells.

The therapeutic efficacy of a lentiviral vector (LV) expressing the herpes simplex virus thymidine kinase (HSV-TK) was studied in an immunocompetent rat glioblastoma model. Intraperitoneal ganciclovir injections (50 mg/kg/day) were administered for 14 consecutive days, resulting in reduced tumor volumes as monitored by MRI. Survival analyses revealed a significant improvement among the LV-expressing HSV-TK (LV-TK)/ganciclovir-treated animals when compared to non-treated control rats. However, a limiting factor in the use of LV has been the suboptimal small-scale production in flasks. Our aim during the translation phase, prior to entering the final pre-clinical and early clinical phases, was to develop a scalable, robust, and disposable manufacturing process for LV-TKs. We also aimed to minimize future process changes and enable production upscaling to make the process suitable for larger patient populations. The upstream process relies on fixed-bed iCELLis technology and transient plasmid transfection. This is the first time iCELLis 500 commercial-scale bioreactor was used for LV production. A testing strategy to determine the pharmacological activity of LV-TK drug product by measuring cell viability was developed, and the specificity of the potency assay was also proven. In this paper we focus on upstream process development while showing analytical development and the proof-of-concept of LV-TK functionality.

Inhibition of urothelial carcinoma through targeted type I interferon-mediated immune activation.

Type I interferon (IFN-I) has potent anti-tumor effects against urothelial carcinoma (UC) and may be an alternative treatment option for patients who do not respond to Bacillus Calmette-Guerin. However, the mechanisms that mediate the IFN-I-stimulated immune responses against UC have yet to be elucidated. Herein, we evaluated the anti-tumor mechanisms of IFN-I in UC in human patients and in mice. Patient tumors from a Phase I clinical trial with adenoviral interferon-α (Ad-IFNα/Syn3) showed increased expression of T cell and checkpoint markers following treatment with Ad-IFNα/Syn3 by RNAseq and immunohistochemistry analysis in 25% of patients. In mice, peritumoral injections of poly(I:C) into MB49 UC tumors was used to incite an IFN-driven inflammatory response that significantly inhibited tumor growth. IFN-I engaged both innate and adaptive cells, seen in increased intratumoral CD8 T cells, NK cells, and CD11b+Ly6G+ cells, but tumor inhibition was not reliant on any one immune cell type. Nonetheless, poly(I:C)-mediated tumor regression and change in the myeloid cell landscape was dependent on IL-6. Mice were also treated with poly(I:C) in combination with anti-PD-1 monoclonal antibody (mAb) to assess for additional benefit to tumor growth and animal survival. When used in combination with anti-PD-1 mAb, IFN-I stimulation prolonged survival, coinciding with inhibition of angiogenesis and enriched gene signatures of metabolism, extracellular matrix organization, and MAPK/AKT signaling. Altogether, these findings suggest IFN-I's immune-driven antitumor response in UC is mediated by IL-6 and a collaboration of immune cells, and its use in combination with checkpoint blockade therapy can increase clinical benefit.

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 rAd-IFNα/Syn3 for Patients With High-Grade, Bacillus Calmette-Guerin-Refractory or Relapsed Non-Muscle-Invasive Bladder Cancer: A Phase II Randomized Study.

Purpose Many patients with high-risk non-muscle-invasive bladder cancer (NMIBC) are either refractory to bacillus Calmette-Guerin (BCG) treatment or may experience disease relapse. We assessed the efficacy and safety of recombinant adenovirus interferon alfa with Syn3 (rAd-IFNα/Syn3), a replication-deficient recombinant adenovirus gene transfer vector, for patients with high-grade (HG) BCG-refractory or relapsed NMIBC. Methods In this open-label, multicenter (n = 13), parallel-arm, phase II study ( ClinicalTrials.gov identifier: NCT01687244), 43 patients with HG BCG-refractory or relapsed NMIBC received intravesical rAd-IFNα/Syn3 (randomly assigned 1:1 to 1 × 1011 viral particles (vp)/mL or 3 × 1011 vp/mL). Patients who responded at months 3, 6, and 9 were retreated at months 4, 7, and 10. The primary end point was 12-month HG recurrence-free survival (RFS). All patients who received at least one dose were included in efficacy and safety analyses. Results Forty patients received rAd-IFNα/Syn3 (1 × 1011 vp/mL, n = 21; 3 × 1011 vp/mL, n = 19) between November 5, 2012, and April 8, 2015. Fourteen patients (35.0%; 90% CI, 22.6% to 49.2%) remained free of HG recurrence 12 months after initial treatment. Comparable 12-month HG RFS was noted for both doses. Of these 14 patients, two experienced recurrence at 21 and 28 months, respectively, after treatment initiation, and one died as a result of an upper tract tumor at 17 months without a recurrence. rAd-IFNα/Syn3 was well tolerated; no grade four or five adverse events (AEs) occurred, and no patient discontinued treatment because of an adverse event. The most frequently reported drug-related AEs were micturition urgency (n = 16; 40%), dysuria (n = 16; 40%), fatigue (n = 13; 32.5%), pollakiuria (n = 11; 28%), and hematuria and nocturia (n = 10 each; 25%). Conclusion rAd-IFNα/Syn3 was well tolerated. It demonstrated promising efficacy for patients with HG NMIBC after BCG therapy who were unable or unwilling to undergo radical cystectomy.