scholarly journals ABC Transporter Inhibition Plus Dexamethasone Enhances the Efficacy of Convection Enhanced Delivery in H3.3K27M Mutant Diffuse Intrinsic Pontine Glioma

Neurosurgery ◽  
2019 ◽  
Vol 86 (5) ◽  
pp. 742-751 ◽  
Author(s):  
Vadim Tsvankin ◽  
Rintaro Hashizume ◽  
Hiroaki Katagi ◽  
James E Herndon ◽  
Christopher Lascola ◽  
...  
Keyword(s):  
Abc Transporter ◽  
Kinase Inhibitor ◽  
Mutant Cell ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Pontine Glioma ◽  
Convection Enhanced Delivery ◽  
P Glycoprotein ◽  
Magnetic Resonance Imaging Mri

Abstract BACKGROUND An impermeable blood–brain barrier and drug efflux via ATP-binding cassette (ABC) transporters such as p-glycoprotein may contribute to underwhelming efficacy of peripherally delivered agents to treat diffuse intrinsic pontine glioma (DIPG). OBJECTIVE To explore the pharmacological augmentation of convection-enhanced delivery (CED) infusate for DIPG. METHODS The efficacy of CED dasatinib, a tyrosine kinase inhibitor, in a transgenic H3.3K27M mutant murine model was assessed. mRNA expression of ABCB1 (p-glycoprotein) was analyzed in 14 tumor types in 274 children. In Vitro viability studies of dasatinib, the p-glycoprotein inhibitor, tariquidar, and dexamethasone were performed in 2 H3.3K27M mutant cell lines. Magnetic resonance imaging (MRI) was used to evaluate CED infusate (gadolinium/dasatinib) distribution in animals pretreated with tariquidar and dexamethasone. Histological assessment of apoptosis was performed. RESULTS Continuous delivery CED dasatinib improved median overall survival (OS) of animals harboring DIPG in comparison to vehicle (39.5 and 28.5 d, respectively; P = .0139). Mean ABCB1 expression was highest in K27M gliomas. In Vitro, the addition of tariquidar and dexamethasone further enhanced the efficacy of dasatinib (P < .001). In Vivo, MRI demonstrated no difference in infusion dispersion between animals pretreated with dexamethasone plus tariquidar prior to CED dasatinib compared to the CED dasatinib. However, tumor apoptosis was the highest in the pretreatment group (P < .001). Correspondingly, median OS was longer in the pretreatment group (49 d) than the dasatinib alone group (39 d) and no treatment controls (31.5 d, P = .0305). CONCLUSION ABC transporter inhibition plus dexamethasone enhances the efficacy of CED dasatinib, resulting in enhanced tumor cellular apoptosis and improved survival in H3.3K27M mutant DIPG.

scholarly journals EXTH-46. ARTIFICIAL INTELLIGENCE-BASED IDENTIFICATION OF COMBINED VANDETANIB AND EVEROLIMUS IN THE TREATMENT OF ACVR1-MUTANT DIFFUSE INTRINSIC PONTINE GLIOMA

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii97-ii97
Author(s):  
Diana Carvalho ◽  
Peter Richardson ◽  
Nagore Gene Olaciregui ◽  
Reda Stankunaite ◽  
Cinzia Emilia Lavarino ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Cell Viability ◽  
Xenograft Model ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Pontine Glioma ◽  
Serine Threonine Kinase ◽  
Orthotopic Xenografts ◽  
Extended Survival

Abstract Somatic mutations in ACVR1, encoding the serine/threonine kinase ALK2 receptor, are found in a quarter of children with the currently incurable brain tumour diffuse intrinsic pontine glioma (DIPG). Treatment of ACVR1-mutant DIPG patient-derived models with multiple inhibitor chemotypes leads to a reduction in cell viability in vitro and extended survival in orthotopic xenografts in vivo, though there are currently no specific ACVR1 inhibitors licensed for DIPG. Using an Artificial Intelligence-based platform to search for approved compounds which could be used to treat ACVR1-mutant DIPG, the combination of vandetanib and everolimus was identified as a possible therapeutic approach. Vandetanib, an approved inhibitor of VEGFR/RET/EGFR, was found to target ACVR1 (Kd=150nM) and reduce DIPG cell viability in vitro, but has been trialed in DIPG patients with limited success, in part due to an inability to cross the blood-brain-barrier. In addition to mTOR, everolimus inhibits both ABCG2 (BCRP) and ABCB1 (P-gp) transporter, and was synergistic in DIPG cells when combined with vandetanib in vitro. This combination is well-tolerated in vivo, and significantly extended survival and reduced tumour burden in an orthotopic ACVR1-mutant patient-derived DIPG xenograft model. Based on these preclinical data, three patients with ACVR1-mutant DIPG were treated with vandetanib and everolimus. These cases may inform on the dosing and the toxicity profile of this combination for future clinical studies. This bench-to-bedside approach represents a rapidly translatable therapeutic strategy in children with ACVR1 mutant DIPG.

scholarly journals DIPG-40. TARGETING MASTER REGULATOR DEPENDENCIES IN DIFFUSE INTRINSIC PONTINE GLIOMA (DIPG)

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii294-iii295
Author(s):  
Jovana Pavisic ◽  
Chankrit Sethi ◽  
Chris Jones ◽  
Stergios Zacharoulis ◽  
Andrea Califano
Keyword(s):  
Gene Expression ◽  
Expression Profiles ◽  
Treatment Options ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Low Grade ◽  
Precision Oncology ◽  
Pontine Glioma ◽  
Convection Enhanced Delivery ◽  
Master Regulator

Abstract Diffuse intrinsic pontine glioma (DIPG) remains a fatal disease with no effective drugs to date. Mutation-based precision oncology approaches are limited by lack of targetable mutations and genetic heterogeneity. We leveraged systems biology methodologies to discover common targetable disease drivers—master regulator proteins (MRs)—in DIPG to expand treatment options. Using the metaVIPER algorithm, we interrogated an integrated low grade glioma and GBM gene regulatory network with 31 DIPG-gene expression signatures to identify tumor-specific MRs by differential expression of their transcriptional targets. Unsupervised clustering identified MR signatures of upregulated activity in RRM2/TOP2A in 13 patients, CD3D in 5 patients, and MMP7, TACSTD2, RAC2 and SLC15A1/SLC34A2 in individual patients, all of which can be targeted. Notably, intratumoral administration of etoposide by convection enhanced delivery was effective in murine proneural gliomas in which TOP2 was identified as a MR while RRM2—targetable by drugs such as cladribine—has been shown to be a positive regulator of glioma progression whose knock-down inhibits tumor growth. We also prioritized drugs by their ability to reverse MR-activity signatures using a large drug-perturbation database. Patients clustered by predicted drug sensitivities with distinct groups of tumors predicted to respond to proteasome inhibitors, Thiotepa or Volasertib all of which have early evidence in treating gliomas. We will refine this analysis in a multi-institutional study of >100 patient gene expression profiles to define MR signatures driving known biological/molecular disease subtypes, use DIPG cell lines recapitulating common MR architectures to optimize therapy prioritization, and validate our findings in vivo.

scholarly journals Diffuse intrinsic pontine glioma: current insights and future directions

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Dilakshan Srikanthan ◽  
Michael S. Taccone ◽  
Randy Van Ommeren ◽  
Joji Ishida ◽  
Stacey L. Krumholtz ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Gene Mutations ◽  
Pediatric Brain Tumor ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Pontine Glioma ◽  
Current Standard ◽  
In Vivo Models ◽  
Landscape Models

AbstractDiffuse intrinsic pontine glioma (DIPG) is a lethal pediatric brain tumor and the leading cause of brain tumor–related death in children. As several clinical trials over the past few decades have led to no significant improvements in outcome, the current standard of care remains fractionated focal radiation. Due to the recent increase in stereotactic biopsies, tumor tissue availabilities have enabled our advancement of the genomic and molecular characterization of this lethal cancer. Several groups have identified key histone gene mutations, genetic drivers, and methylation changes in DIPG, providing us with new insights into DIPG tumorigenesis. Subsequently, there has been increased development of in vitro and in vivo models of DIPG which have the capacity to unveil novel therapies and strategies for drug delivery. This review outlines the clinical characteristics, genetic landscape, models, and current treatments and hopes to shed light on novel therapeutic avenues and challenges that remain.

scholarly journals MODL-12. DEVELOPMENT OF A NOVEL IMMUNOCOMPETENT MOUSE MODEL FOR DIFFUSE INTRINSIC PONTINE GLIOMA

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii413-iii413
Author(s):  
Maggie Seblani ◽  
Markella Zannikou ◽  
Katarzyna Pituch ◽  
Liliana Ilut ◽  
Oren Becher ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Mouse Model ◽  
Growth Factor Receptor ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Pontine Glioma ◽  
Time Of Application ◽  
Tumor Associated Antigen ◽  
Sarcoma Virus

Abstract Diffuse intrinsic pontine glioma (DIPG) is a devastating brain tumor affecting young children. Immunotherapies hold promise however the lack of immunocompetent models recreating a faithful tumor microenvironment (TME) remains a challenge for development of targeted immunotherapeutics. We propose to generate an immunocompetent DIPG mouse model through induced overexpression of interleukin 13 receptor alpha 2 (IL13Rα2), a tumor-associated antigen overexpressed by glioma cells. A model with an intact TME permits comprehensive preclinical assessment of IL13Rα2-targeted immunotherapeutics. Our novel model uses the retroviral avian leucosis and sarcoma virus (RCAS) for in vivo gene delivery leading to IL13Rα2 expression in proliferating progenitor cells. Transfected cells expressing IL13Rα2 and PDGFB, a ligand for platelet derived growth factor receptor, alongside induced p53 loss via the Cre-Lox system are injected in the fourth ventricle in postnatal pups. We validated the expression of PDGFB and IL13Rα2 transgenes in vitro and in vivo and will characterize the TME through evaluation of the peripheral and tumor immunologic compartments using immunohistochemistry and flow cytometry. We confirmed expression of transgenes via flow cytometry and western blotting. Comparison of survival dynamics in mice inoculated with PDGFB alone with PDGFB+IL13Rα2 demonstrated that co-expression of IL13Rα2 did not significantly affect mice survival compared to the PDGFB model. At time of application, we initiated experiments to characterize the TME. Preliminary data demonstrate establishment of tumors within and adjacent to the brainstem and expression of target transgenes. Preclinical findings in a model recapitulating the TME may provide better insight into outcomes upon translation to clinical application.

scholarly journals Preclinical and clinical evaluation of German-sourced ONC201 for the treatment of H3K27M-mutant diffuse intrinsic pontine glioma

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Ryan J Duchatel ◽  
Abdul Mannan ◽  
Ameha S Woldu ◽  
Tom Hawtrey ◽  
Phoebe A Hindley ◽  
...  
Keyword(s):  
Biological Activity ◽  
High Resolution Mass Spectrometry ◽  
The United States ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Resonance Spectroscopy ◽  
Pontine Glioma ◽  
Drug Bioavailability ◽  
Proliferation And Apoptosis

Abstract Background Diffuse intrinsic pontine glioma (DIPG) is a fatal childhood brainstem tumor for which radiation is the only treatment. Case studies report a clinical response to ONC201 for patients with H3K27M-mutant gliomas. Oncoceutics (ONC201) is only available in the United States and Japan; however, in Germany, DIPG patients can be prescribed and dispensed a locally produced compound—ONC201 German-sourced ONC201 (GsONC201). Pediatric oncologists face the dilemma of supporting the administration of GsONC201 as conjecture surrounds its authenticity. Therefore, we compared GsONC201 to original ONC201 manufactured by Oncoceutics Inc. Methods Authenticity of GsONC201 was determined by high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy. Biological activity was shown via assessment of on-target effects, in vitro growth, proliferation, and apoptosis analysis. Patient-derived xenograft mouse models were used to assess plasma and brain tissue pharmacokinetics, pharmacodynamics, and overall survival (OS). The clinical experience of 28 H3K27M+ mutant DIPG patients who received GsONC201 (2017–2020) was analyzed. Results GsONC201 harbored the authentic structure, however, was formulated as a free base rather than the dihydrochloride salt used in clinical trials. GsONC201 in vitro and in vivo efficacy and drug bioavailability studies showed no difference compared to Oncoceutics ONC201. Patients treated with GsONC201 (n = 28) showed a median OS of 18 months (P = .0007). GsONC201 patients who underwent reirradiation showed a median OS of 22 months compared to 12 months for GsONC201 patients who did not (P = .012). Conclusions This study confirms the biological activity of GsONC201 and documents the OS of patients who received the drug; however, GsONC201 was never used as a monotherapy.

scholarly journals Entrectinib, a TRK/ROS1 inhibitor with anti-CNS tumor activity: differentiation from other inhibitors in its class due to weak interaction with P-glycoprotein

2020 ◽  
Vol 22 (6) ◽  
pp. 819-829 ◽  
Author(s):  
Holger Fischer ◽  
Mohammed Ullah ◽  
Cecile C de la Cruz ◽  
Thomas Hunsaker ◽  
Claudia Senn ◽  
...  
Keyword(s):  
Steady State ◽  
Lipid Membrane ◽  
Kinase Inhibitor ◽  
Ex Vivo ◽  
Intracranial Tumor ◽  
Brain Penetration ◽  
In Vivo Experiments ◽  
P Glycoprotein

Abstract Background Studies evaluating the CNS penetration of a novel tyrosine kinase inhibitor, entrectinib, proved challenging, particularly due to discrepancies across earlier experiments regarding P-glycoprotein (P-gp) interaction and brain distribution. To address this question, we used a novel “apical efflux ratio” (AP-ER) model to assess P-gp interaction with entrectinib, crizotinib, and larotrectinib, and compared their brain-penetration properties. Methods AP-ER was designed to calculate P-gp interaction with the 3 drugs in vitro using P-gp–overexpressing cells. Brain penetration was studied in rat plasma, brain, and cerebrospinal fluid (CSF) samples after intravenous drug infusion. Unbound brain concentrations were estimated through kinetic lipid membrane binding assays and ex vivo experiments, while the antitumor activity of entrectinib was evaluated in a clinically relevant setting using an intracranial tumor mouse model. Results Entrectinib showed lower AP-ER (1.1–1.15) than crizotinib and larotrectinib (≥2.8). Despite not reaching steady-state brain exposures in rats after 6 hours, entrectinib presented a more favorable CSF-to-unbound concentration in plasma (CSF/Cu,p) ratio (>0.2) than crizotinib and larotrectinib at steady state (both: CSF/Cu,p ~0.03). In vivo experiments validated the AP-ER approach. Entrectinib treatment resulted in strong tumor inhibition and full survival benefit in the intracranial tumor model at clinically relevant systemic exposures. Conclusions Entrectinib, unlike crizotinib and larotrectinib, is a weak P-gp substrate that can sustain CNS exposure based on our novel in vitro and in vivo experiments. This is consistent with the observed preclinical and clinical efficacy of entrectinib in neurotrophic tropomyosin receptor kinase (NTRK) and ROS1 fusion-positive CNS tumors and secondary CNS metastases.

scholarly journals 09 Could DLX2 regulation of neural progenitor cell fate contribute to differentiation of diffuse intrinsic pontine glioma (DIPG)?

2018 ◽  
Vol 45 (S3) ◽  
pp. S16-S16
Author(s):  
M Nevin ◽  
X Song ◽  
S Japoni ◽  
J Zagozewski ◽  
Q Jiang ◽  
...  
Keyword(s):  
Cell Fate ◽  
Neural Progenitor Cell ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Gabaergic Interneuron ◽  
Acid Decarboxylase ◽  
Pontine Glioma ◽  
Double Knockout ◽  
Promoter Sequences

Introduction: Diffuse intrinsic pontine glioma (DIPG) is refractory to therapy. The identification of histone H3.1/H3.3 K27M mutations in most DIPG has provided new insights. The DLX homeobox genes are expressed in the developing forebrain. The Dlx1/Dlx2 double knockout (DKO) mouse loses tangential GABAergic interneuron migration to the neocortex. We have identified genes that encode glutamic acid decarboxylase (GAD) enzymes as direct targets of DLX1/DLX2. In DIPG patients with H3.3 K27M mutations there is decreased Dlx2 and increased expression of the myelin transcription factor, Myt1. Methods and Results: We used bioinformatics approaches and chromatin immunoprecipitation (ChIP) assays to identify Olig2, Nkx2.2 and Myt1 promoter sequences as candidate DLX2 targets in vivo. DNA binding specificity was confirmed. The functional consequences of Dlx2 co-expression with reporter constructs of ChIP-isolated promoter fragments of Olig2 and Nkx2.2 demonstrated repression of gene targets in vitro. qPCR showed increased Olig2 and Nkx2.2 expression in the DKO forebrain. Stable transfection of a murine DIPG cell line with Dlx2 resulted in increased Gad1 and Gad2 and decreased Olig2 and Nkx2.2 expression. Of significance, we demonstrated decreased expression of H3.3 K27M and restoration of H3.3 K27 tri-methylation (me3). Conclusions: DLX transcription factors promote GABAergic interneuron and concomitant inhibition of oligodendroglial differentiation in neural progenitors by repression of a suite of genes including Olig2 and Nkx2.2. Restoration of H3 K27me3 expression in DIPG provides a promising lead towards exploration of differentiation as a therapeutic strategy for DIPG.

Acquired Extramedullary Resistance to Dasatinib Due to Selection of Philadelphia-Positive Lymphoblast Clone Harboring a T315I BCR-ABL Gene Mutation: Reversal by Dose Escalation and Hydroxyurea.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4579-4579
Author(s):  
Tuija Lundan ◽  
Franz Gruber ◽  
Martin Hoglund ◽  
Bengt Simonsson ◽  
Sakari Knuutila ◽  
...  
Keyword(s):  
Dose Escalation ◽  
Low Dose ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Mutant Cell ◽  
Skin Lesions ◽  
Fish Analysis ◽  
Imatinib Resistance

Abstract Most patients with advanced Philadelphia-positive (Ph+) hematologic malignancies develop resistance to imatinib. Acquired resistance to imatinib is commonly a result of selection for subclones bearing point-mutations in the catalytic kinase domain of BCR-ABL. Dasatinib (BMS-354825), a dual-specific SRC/ABL kinase inhibitor, has shown activity in imatinib-resistant Ph+ diseases both in vitro and in vivo. Preliminary data also indicate efficacy in patients. Based on laboratory evidence, dasatinib appears to inhibit all known BCR-ABL mutant clones, with the exception of T315I, a gatekeeper mutation conferring resistance to several kinase inhibitors. Here we describe a Ph+ ALL patient, who initially developed imatinib resistance (hematologic) possibly due to BCR-ABL amplification (FISH). His disease relapsed as extensive extramedullary tumors bearing wild-type BCR-ABL. He received dasatinib 70 mg BID as part of the BMS CA180–015 study and achieved a very good partial remission. After 5 months of therapy, the disease relapsed as a solitary axillary tumor and several small palmar skin lesions. He also had blasts in the CSF indicative of neuroleukemia. Bone marrow remained in cytogenetic remission. FISH analysis of the tumor revealed 2–3 copies of BCR-ABL as previously. A highly sensitive, quantitative, mutation-specific PCR (Gruber F, ASH 2004) showed the presence of the T315I mutation, which was confirmed by sequencing. A very low level of T315I transcript was also detected in the blood. Dasatinib dose was escalated to 100 mg BID, and low-dose hydroxyurea 500 mg BID was initiated to putatively enhance the access of dasatinib in the CSF sanctuary. He also received two doses of i.t. therapy (methotrexate, cytarabine). Patient’s symptoms (confusion, headache) related to neuroleukemia resolved rapidly, skin lesions disappeared and axillary tumor decreased in size. He is currently symptom-free and has no signs of active ALL. The favorable response to dasatinib dose escalation and low-dose hydroxyurea was unexpected. Preclinical data on T315I mutant cell lines would argue against a significant concentration dependence in kinase inhibition by dasatinib. Putatively, targets other than BCR-ABL may be of importance in particular in Ph+ ALL (e.g. Src, Lyn), and this effect may account for the response. Similar off-target activity of hydroxyurea is utilized in clinical trials to overcome resistance to multidrug HIV therapy - a setting resembling current treatment of Ph+ malignancies with kinase inhibitors.

EXTH-58. THERAPEUTIC HDAC INHIBITION IN HYPERMUTANT DIFFUSE INTRINSIC PONTINE GLIOMA

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi176-vi176
Author(s):  
Alyssa Noll ◽  
Matt Biery ◽  
Carrie Myers ◽  
Danyelle Paine ◽  
Ye Zheng ◽  
...  
Keyword(s):  
Tumor Regression ◽  
Hdac Inhibitors ◽  
Cancer Cell Line ◽  
Residual Tumor ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Cross Resistance ◽  
Pontine Glioma ◽  
Dismal Prognosis

Abstract Diffuse intrinsic pontine glioma (DIPG) continues to carry a dismal prognosis despite a growing understanding of its epigenetic regulation. While generally reclassified as diffuse midline glioma, H3 K27M-mutant (DMG), a subgroup of DIPGs do not harbor the classic histone mutation, with a further subset exhibiting a hypermutant phenotype. To evaluate whether hypermutant DIPG shares transcriptional vulnerabilities with H3K27M-mutant DMG, we screened a biopsy-derived treatment-naive PMS2 mutant DIPG model (PBT-24FH) for sensitivity to a panel of HDAC inhibitors (HDACi). In vitro evaluation of cell viability revealed the low nanomolar IC50 of quisinostat (50nM) and romidepsin (2nM). Dose-dependent increases in H3 acetylation and c-PARP were confirmed by western blot. Despite romidepsin’s superior potency in vitro, quisinostat demonstrated greater efficacy in an in vivo PBT-24FH flank study. 42 days following drug initiation, quisinostat-treated mice displayed dramatic tumor regression (mean volume= 33mm3, n= 7) compared to mice treated with romidepsin (mean volume= 669mm3, n= 7)(p= 0.005), or vehicle (mean volume= 990mm3, n= 6)(p< 0.001). Immunohistochemistry of quisinostat-treated tumors revealed few residual tumor cells displaying a low proliferative index. To evaluate cross-resistance, romidepsin-treated mice (mean volume= 1158mm3, n= 2) were switched to quisinostat treatment and displayed swift tumor regression (mean volume after 25 days of quisinostat= 419mm3), emphasizing quisinostat’s in vivo cytotoxic effect against both large tumors and tumors previously treated by another HDACi. To evaluate quisinostat’s effect on other hypermutant tumors, we tested HCT-116, a colon cancer cell line bearing a biallelic MLH1 deletion and observed similar cytotoxicity. We also aim to repeat these studies utilizing additional pediatric hypermutant high grade glioma models. Transcriptomic and proteomic investigations are underway to identify the mechanism of action underlying quisinostat-induced cytotoxicity. Ultimately, we are the first to demonstrate in vivo efficacy of the HDACi quisinostat against hypermutant DIPG, supporting further investigation and clinical advancement.

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