Citations

Abstract Bladder cancer is the 9th most diagnosed cancer worldwide with higher incidences reported in Europe and the United States. Here, we evaluate the performance of a novel, commercially available multiplex immunoassay querying for 10 proteins associated with a bladder cancer diagnostic signature (Oncuria®-Detect, Nonagen Bioscience Corp, Los Angeles, CA, US) for the detection of de novo bladder cancer, in a large prospectively collected real world cohort comprised of 995 patients, across seven centers, presenting with hematuria. The results were compared with the patients’ clinical data and final diagnosis as defined by the results of cystoscopy, with a prevalence of bladder cancer of 15.9%. In the test cohort, Oncuria®-Detect detected bladder tumors in 94/109 cancers, giving overall sensitivity of 86.2% and an overall negative predictive value (NPV) of 96.7% with corresponding specificity of 80.2% with favorable performance characteristics in high grade bladder cancer and muscle-invasive bladder cancer. Patient summary: We conducted a large cross-sectional clinical study for detecting de novo bladder cancer with a novel, simple urine test (Oncuria®-Detect), which measures 10 bladder cancer associated proteins in a single voided urine sample. We analyzed urines from 995 patients and demonstrated that the new urine test can detect bladder cancer with a high degree of accuracy, specifically in patients with high grade or high stage disease. In conclusion, the novel Oncuria®-Detect urine test can be used to help detect new bladder cancers. Citation Format: Ian Pagano, Sergei Tikhonenkov, Florence Le Calvez-Kelm, Steve Goodison, Zhen Zhang, Toru Sakatani, Kaoru Murakami, Howard Kim, Riko Lee, Sunao Tanaka, Charles J Rosser, Hideki Furuya. Performance of the Oncuria®-Detect test for the evaluation of patients presenting with hematuria: Results from a real world clinical setting [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A071.

Introduction: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disorder characterized by fibrofatty replacement of myocardial tissue, creating areas of electrical heterogeneity and increasing the risk of ventricular arrhythmias (VAs) and sudden cardiac death (SCD). Catheter ablation is commonly performed in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) for management of ventricular arrhythmias (VAs). Whether catheter ablation affects cardiac function post-procedurally is uncertain. Research Question: Does catheter ablation for ARVC result in acute change in cardiac function? Goals/Aims: To assess the impact of catheter ablation for VAs on cardiac function in the acute post-procedure setting. Methods: This retrospective study included patients with ARVC who underwent catheter ablation for VAs at Mayo Clinic. Cardiac function was assessed on pre- and post-procedure transthoracic echocardiograms (TTEs). Post-procedure TTEs were obtained within 4 weeks after the ablation procedure. Right ventricular (RV) enlargement and systolic dysfunction were evaluated as continuous variables (0=none, 1=mild, 2=mild-moderate, 3=moderate, 4=moderate-severe, 5=severe). Results: The study included 32 patients who underwent a total of 44 ablations. Mean age at the time of ablation was 49±16 years, and 24 (75%) were male. After a mean follow-up duration of 2.6±5.5 days, there was a significant worsening in mean RV dysfunction (1.6±1.5 to 2.0±1.4, P = 0.001). There were no significant changes in mean left ventricular ejection fraction (LVEF), left ventricular (LV) dimensions, and RV size. 6 (14%) patients had a >5% decline in LVEF, and 14 (32%) patients had worsening RV function. Transient inotropic support was required in 4 (9%) patients. Conclusion(s): This study is the first to assess the acute impact of catheter ablation for VAs on cardiac function in ARVC patients. These results underscore the importance of careful post-procedure monitoring and planning of the ablation target in these patients to avoid excessive ablation and therefore impairment in cardiac function.

Background: About one in five adults at age 40 will develop heart failure (HF) during their lifetime. Risk factors for HF (e.g., hypertension, etc.) alter cardiomyocytes structure and function resulting in HF. At the cellular level, these changes consist of mis/over-expression of genes that regulate cardiac identity (e.g., CamK2d, PKC, etc). The current paradigm for treating HF is pharmacological intervention or surgery; however, with few exceptions, the condition worsens with time. We are proposing a paradigm-shift for treating HF from a drug-centric system to a molecular approach that would reverse hypertrophy and adverse remodeling. Methods: A cardiac targeting peptide (CTP) was generated and linked by disulfide bond to miRNA106a, which was then introduced into a HF mouse model to measure its ability to reverse multiple heart failure parameters. CTP-miRNA106a was also introduced into a human cardiac cell line, followed by multiple analyses including Western Blot, qPCR, FACS, immunofluorescence all used to identify mechanism(s) utilized by CTP-miRNA106a to reverse HF characteristics. Results: Bio-distribution studies showed CTP delivered its miRNA106a cargo specifically to the heart within 30 mins, followed by clearance of CTP from the heart to the kidneys and liver by 3-5hrs post systemic drug injection. MiRNA106a persisted in cardiomyocytes until day 7 (latest tested time-point). CTP-miRNA106a reversed Ang2/Iso induced hypertrophy in 90% of the experimental mice ( Fig1 ). We also identified two potential HF intracellular signaling mechanisms (PLCb1/PKC/IP3 and NfkB) targeted by CTP-miRNA106a that could benefit both types of HF, HFrEF and HFpEF. PLCβ1 is a direct target for miRNA106a while the Nfkb pathway is indirectly targeted by decreased Camk2d (an miRNA106a target) signaling to IκBα. NfkB activity is quelled by miRNA106a. Conclusions: Our approach utilizes the function of miRNA106a to downregulate genes involved in cardiac hypertrophy and inflammation through the PLCb1 and CamKIId/Nfkb pathways. Most importantly, using a CTP-miRNA106a, we show delivery of miRNA106a cargo is specific to cardiomyocytes both in vitro and in vivo and that once delivered, many HF parameters including hypertrophy are reversed.

Abstract Glioblastoma (GBM), the most common and deadly primary brain tumor, exerts profound local and systemic immunosuppressive effects through a variety of mechanisms. Tumor-derived extracellular vesicles (EVs) are increasingly appreciated as critical mediators of these effects. In surveying the tumor-immune microenvironment in samples of ultrasonic aspirate collected during surgical resection of GBM (n=13), we identified several key immunomodulatory markers expressed across a range of myeloid cell populations. Particularly, we found TIGIT, classically understood as a T cell inhibitory protein, expressed across a range of myeloid cell populations in patient samples, including in myeloid-derived suppressor cells (MDSCs, 46.84±16.78% of total monocytic MDSCs). Using EVs collected from patient-derived cell lines, we were able to recapitulate these effects upon co-culture with monocytes derived from the peripheral blood of healthy donors (n=7). Furthermore, Induced MDSCs significantly inhibit T cells proliferation (70.97±8.454%, compared to control 19.4±5.71; p<0.03), concomitant with a surge in Th2 immune responses via TIGIT/CD155 axis. This effect was reversed after TIGIT silencing, indicating a TIGIT-dependent immune suppression in the GBM microenvironment. Our study indicates EV-induced TIGIT upregulation in myeloid cells as a crucial immunosuppressive mechanism in glioblastoma, with potential therapeutic applications.

Abstract Standard of care (SOC) for ndGBM begins with maximal safe resection followed by adjuvant radiotherapy and temozolomide, and maintenance temozolomide. IGV-001 is an autologous biologic-device combination immunotherapy for the treatment of ndGBM that consists of autologous GBM tumor cells and an antisense oligonucleotide against IGF-1R mRNA, irradiated and administered via biodiffusion chambers implanted in the abdomen. In a phase 1b study, IGV-001 was well tolerated without unexpected adverse events in subjects with ndGBM. Multiple efficacy signals were observed, including significant improvements in progression-free survival (PFS), overall survival (OS), radiographic evidence of tumor response, and changes in immune response biomarkers. Here, we present early safety data from the phase 2b randomized, multicenter, double-blind, placebo-controlled study (NCT04485949) designed to assess efficacy and safety of IGV-001 in subjects with ndGBM across 20 sites in the United States. After surgical resection, subjects were randomized 2:1 and treated with IGV-001 or placebo followed by SOC. The primary outcome is PFS, defined as the time from randomization to first progression, as determined by blinded central radiology review, or death. Secondary outcomes include OS, defined as the time from randomization to death due to any cause, and safety. As of May 22, 2024, 99 subjects were randomized and 95 implanted with IGV-001 or placebo plus SOC. A total of 39/45 (86.7%) subjects had sufficient follow-up time after initiated treatment with concurrent radiation and temozolomide. Nine of 72 randomized (12.5%) discontinued treatment, including 7 who stopped during the SOC treatment period. None ceased treatment for adverse events, protocol deviations, or death. A total of 11/72 (15.3%) randomized subjects discontinued the study after randomization. A review of blinded safety data did not show any emerging risk and supports no change to the benefit-risk profile of IGV-001 versus placebo. Updated data will be presented.

Abstract BACKGROUND Lynch syndrome is caused by pathogenic germline variants in the DNA mismatch repair (MMR) genes, predisposing individuals to malignancies, including glioblastoma (GBM). MMR-deficient tumors are resistant to monofunctional alkylators such as temozolomide but not to bifunctional alkylators such as the nitrosourea lomustine. Anti-programmed cell death protein 1 (PD1) immune checkpoint inhibitor (ICI) pembrolizumab represents another treatment option, which is approved by the United States Food and Drug Administration (FDA) for the treatment of mismatch repair deficient cancers. METHODS We present a patient with multifocal GBM and Lynch syndrome who experienced rapid progression following standard-of-care chemoradiation, followed by durable responses to lomustine and then to pembrolizumab. RESULTS A 58-year-old man with Lynch syndrome (MSH2 mutation) and prior history of colon cancer presented with seizures. Magnetic resonance imaging (MRI) brain identified right frontal and left parietal masses. Right frontal tumor was resected; pathology was consistent with GBM, IDH wildtype, MGMT-unmethylated. Both lesions were treated with radiation therapy (60 Gy, 30 fractions) with concurrent and adjuvant temozolomide. After two cycles of adjuvant temozolomide, his left parietal tumor progressed and was subtotally resected, followed by four cycles of lomustine (stopped due to myelotoxicity). He remained progression-free for 15 months. Surveillance MRI identified new enhancement involving the left frontal lobe, left periventricular white matter, and right internal auditory canal, concerning for leptomeningeal dissemination. MRI spine identified no additional lesions. Cerebrospinal fluid cytology was negative for tumor cells on two occasions. Patient was treated with pembrolizumab. He remains on treatment with stable disease four months after ICI initiation and 31 months after GBM diagnosis. CONCLUSIONS Patients with MMR-deficient GBM resist standard chemoradiation. Alternatives such as nitrosourea or ICI therapy may achieve durable responses. While data is insufficient to administer these agents as upfront therapy in this specific setting, both should be considered as options for recurrent disease.

Abstract Glioblastoma (GBM) presents as a highly aggressive and malignant brain tumor with limited treatment options. Despite the availability of existing therapies, the invasive characteristics of GBM frequently result in tumor recurrence and poor prognosis. We previously developed a B-cell-based therapy (BVax) that has shown promising results in its ability to induce therapeutic responses in preclinical models of GBM. Our research revealed potency of BVax can be attributed to its robust antigen-presenting capability, cognate antigen specificity with T cells, and ability to generate tumor-reactive antibodies. The present study aims to characterize the unique antigenic reactivity of BVax-derived antibodies by evaluating their immunological effects and therapeutic potential in both murine models and GBM patient-specific samples. Leveraging CD45.1 and CD45.2 congenic mouse models, we first revealed that BVax preferentially migrated to glioma-bearing brains upon intravenous injection, resulting in a CD38+CD20-CD19+ plasmablast phenotype. To further characterize the reactivity of BVax-derived immunoglobulins (Ig), we utilized proteomic analysis and identified preferential targets of Gelsolin, Fibronectin, Versican, Fibrinogen, and collagen type IV alpha, commonly associated with cell motility and the extracellular matrix. Microdialysis data confirmed the increased presence of many of these BVax-derived Igs-recognized antigens in tumor regions compared to normal brain regions in GBM patients. Utilizing purified BVax-derived antibodies from patient specimen, in vitro cell motility assays demonstrated a significant prevention of the invasion and migration of cell lines from patient derived xenograft (PDX). In this study, we concluded that BVax elicits antitumor activity through targeted migration to tumor-bearing regions, differentiation into plasmablasts, and robust secretion of specific Igs that retain the ability to inhibit functionalities associated with cell invasion and migration. Here, we present the first in-depth study that characterizes GBM patients’ antibody reactivity, specifically a subset of inflammatory B cells (BVax) with therapeutic effects that offer an indication for a new direction of immunotherapies.

Abstract While serial sampling of glioma tissue is rarely performed before recurrence, cerebrospinal fluid (CSF) can be acquired serially to evaluate candidate monitoring and pharmacodynamic biomarkers in patients with gliomas. However, the impact of key variables to consider in longitudinal CSF, including anatomical location and post-surgical changes, remains unknown. To that end, pre- versus post-resection intracranial CSF samples from patients with gliomas were obtained at early (1-16 days; n=20) or delayed (86-153 days; n=11) timepoints, as well as lumbar-versus-intracranial glioma CSF samples (n=14). Using aptamer-based proteomics, we identified significant differences in the glioma CSF proteome between lumbar, subarachnoid, and ventricular CSF. Indeed, intracranial CSF in paired lumbar/intracranial samples had nearly 1600 unique aptamers, regardless of which intracranial location was compared to the paired lumbar CSF, including in enrichment style analyses that evaluated the overlap between protein states. Importantly, resection had a significant, evolving longitudinal impact on the CSF proteome, with subsets of proteins associated with early versus delayed post-resection changes, many of which were enriched for inflammatory-related pathways. Interestingly, despite increased contamination from surgical debris, enrichment for plasma-associated proteins decreased with resection (FDR: 0.000), suggesting that a portion of the baseline glioma panel could be derived from plasma-originating analytes due to blood-brain barrier disruption. Despite these challenges, our data still revealed preliminary candidate monitoring biomarkers, such as brevican, that increased with progression (example patient: fold-change of 3.58x and 2.08x through lomustine and bevacizumab, respectively), but not pseudoprogression (Fold change less than 1.5). Serial intracranial CSF samples suggested the early potential for disease monitoring and evaluation of pharmacodynamic impact of targeted therapies, including bevacizumab and pembrolizumab. In conclusion, our available data to date suggest that the intracranial glioma CSF proteome provides an abundant and evolving source of candidate biomarkers to longitudinally discern the impact of resection and systemic treatments.

Abstract Glioblastoma is the most common malignant primary brain tumor and is universally fatal. Treatment involves maximal safe resection with adjuvant chemoradiation. Poor prognosis in glioblastoma is multifactorial, and local and systemic immunosuppression is an important factor. Extracellular vesicles (EVs) are small, membrane-bound particles released by cells into the external environment. They play a key role in intercellular communication. In glioblastomas, EVs regulate immunosuppression through induction of myeloid-derived suppressor cells (MDSCs) in a process dependent on the PD-1/PD-L1 and IL-6 axes. Primary cilia are microtubule-based organelles that play crucial roles in various cellular processes and signal transduction cascades. We recently showed that primary cilia modulate IL-6 expression and consequently, MDSC induction. Comparative proteomic analysis of EVs derived from human glioblastoma cells devoid of cilia showed loss of ICAM-1 expression compared to control glioblastoma cells. ICAM-1 (Intercellular Adhesion Molecule-1) is a cell surface glycoprotein that mediates cell-cell adhesion and immune responses. In this study, we showed that depletion of primary cilia in human glioblastoma cells result in increased PD-L1 but loss of IL-6 and ICAM-1. RNAi-meidated loss of ICAM-1 was synergistic with primary cilia depletion in preventing MDSC inductionn normal human monocytes exposed to glioblastoma-derived EVs. Exogenous IFN-g was sufficient to restore IL-6 levels and MDSC induction despite loss of primary cilia and ICAM-1 suggesting that primary cilia act upstream of IFN-g, IL-6 and ICAM-1 in glioblastoma-mediated MDSC induction. This study is the first to connect primary cilia signal transduction to IL-6 and ICAM-1 expression and to MDSC induction. The evidence suggests a potential parallel primary cilia regulatory cascade independent of the PD-L1 axis that controls tumor-mediated immunosuppression. These results may inform novel therapeutic strategies aimed at increasing efficacy of immunotherapy in the glioblastoma and other neoplastic processes.

Abstract BACKGROUND Patients with meningiomas that have progressed after surgery and/or radiation have limited treatments. Loss of NF2 and CDKN2A/B are common in higher-grade meningiomas and promote meningioma progression. We evaluated the efficacy of abemaciclib, a cyclin-dependent kinase (CDK) 4/6 inhibitor, as part of Alliance A071401, a genomically-driven phase II trial in recurrent or progressive meningiomas. METHODS Eligible patients (pts) with grade 2/3 tumors and NF2 mutations or CDK pathway alterations were treated with abemaciclib 200 mg orally twice daily. Two co-primary endpoints were used: progression-free survival at 6 months (PFS6) and response rate (RR); the trial would be declared positive if either endpoint was met. Twenty-four evaluable pts provided ≥85% power to detect a PFS6 ≥41.5% (vs. null 15%; alpha=0.02), and ≥89% power to detect RR ≥20% (vs. null 2.5%; alpha=0.021). RESULTS Of 83 pts screened while the abemaciclib arm was open between September 15, 2021 and October 3, 2022, 36 eligible pts received abemaciclib. The observed PFS6 rate in the first 24 evaluable pts was 54% (95% CI 33-75%), thus the study met PFS6 endpoint. Of all 35 evaluable pts, median PFS was 7.6 months (95% CI 3.6-17.1 months), estimated 6-month PFS was 55% (95% CI 40-75%) and estimated 6-month OS was 88% (95% CI 77-100%). No objective responses were observed. Of the 36 pts who started treatment, two had a grade 4 adverse event at least possibly related to treatment which included ALT elevation(1), AST elevation(1) and vomiting(1). Patients with NF2 alterations (n=24) had favorable PFS6 outcomes (58%, 95% CI 37-78%) compared to those with CDK (n=4, 25%, 95% CI 1-81%) and CDK+NF2 alterations (n=7, 29% 95% CI 4-71%), (Fisher’s Exact p=0.036). CONCLUSIONS Abemaciclib was well-tolerated and resulted in improved PFS6, meeting the trial’s co-primary endpoint. Abemaciclib warrants further investigation for the treatment of patients with progressive meningiomas.