SBIR-STTR Award

Glioblastoma (GBM) is the most lethal form of adult brain cancers with a median survival of <15 months despite aggressive standard chemoradiation. GBM are formed by GBM stem-like cells (GSCs) - a major contributor to tumor recurrence and a natural focus for therapeutic development. There are two main reasons responsible for treatment failure: 1) high intra- and inter-tumor cellular and molecular heterogeneity with multiple subclones possessing distinct genetic determinants; 2) GSCs exhibit multiple redundant signaling pathways requiring simultaneous targeting of overlapping pathways. We have invented and biologically validated a novel tandem computational platform, GeneRep-nSCORE that integrates large-scale gene expression profiles with genomic changes to identify common founding alterations or master regulators of GSCs that span a large number, if not all, GSC subclones within and across GBM tumors. We discovered such a core set of four common master regulators in GCSs that are outstanding targets for clinical development. Expression of these four factors was sufficient to reprogram normal astrocytes to GSCs, whereas their depletion profoundly abrogated GSCs, and thus tumor development in vivo, in all eight lines of patient-derived GSCs of varied genetic and molecular backgrounds examined to date. The goal of this application is to develop a customized set of Adeno-associated virus (AAV)-based genetic tools to target the whole spectrum of GSCs (Phase I) for the purpose of delivering targeting constructs to deplete the four common master regulators responsible for malignant transformation and proliferation in GSCs (Phase II). The specific objectives of this proposal are: (i) using directed evolution and available combinatorial AAV capsid library, and for the first time, introducing a dynamic mode of administration of a library reagent over the time course of tumor progression, to greatly increase the probability of identifying novel AAV variants specifically targeting slow-, and fast-cycling GSCs in patient-derived xenograft models (PDX) (Phase I); (ii) To design and validate a panel of AAV vectors that express shRNAs targeting core master regulators of GSCs to identify leads for preclinical testing; (iii) To optimize modes of viral delivery, pharmacokinetics and pharmacodynamics parameters, and safety and toxicity in normal and PDX treated with lead targeting AAV cassettes; and (iv) Based on these results, tools and basic DMPK data created, to conduct preclinical efficacy studies in PDX treated with lead targeting AAV cassettes either alone or in combination with standard chemoradiotherapy (Phase II) to prepare for an investigative new drug application for clinical testing in patients with GBM, and for commercial development of this novel technology.

Project Terms:
Address; adeno-associated viral vector; Adult; Apoptotic; Astrocytes; base; Biological; Biological Assay; Biology; Capsid; CD44 gene; Cell surface; Cells; chemoradiation; clinical application; clinical development; Clinical Trials; Collaborations; combinatorial; computerized tools; Custom; Data; Dependovirus; design; Development; Directed Molecular Evolution; DNA cassette; Drug Kinetics; efficacy study; Environment; Exhibits; Expression Profiling; Florida; Flow Cytometry; Gene Expression; gene therapy; Genetic; Genetic Determinism; Genomics; Glioblastoma; Goals; Heterogeneity; improved; In Vitro; in vivo; in vivo evaluation; Individual; Injections; Inter-tumoral heterogeneity; interdisciplinary approach; knock-down; Lead; lead optimization; Libraries; Malignant - descriptor; Malignant neoplasm of brain; Modeling; Molecular; mouse model; new technology; novel; novel therapeutics; Pathway interactions; Patients; Pharmacodynamics; Phase; Platelet Factor 4; Population; Population Heterogeneity; pre-clinical; preclinical efficacy; Preclinical Testing; Probability; Process; programs; Radiation; Reagent; Recurrence; Regimen; research clinical testing; Safety; Serotyping; Signal Pathway; small hairpin RNA; Specificity; Stem cells; stem-like cell; Systems Biology; Technology; therapeutic development; Time; tool; Toxic effect; transduction efficiency; Treatment Failure; tumor; tumor progression; tumorigenesis; Universities; Variant; vector; Viral; Viral Vector; Xenograft Model; Xenograft procedure;

Glioblastoma (GBM) is the most lethal form of adult brain cancers with a median survival of <15 months despite aggressive standard chemoradiation. GBM are formed by GBM stem-like cells (GSCs) - a major contributor to tumor recurrence and a natural focus for therapeutic development. There are two main reasons responsible for treatment failure: 1) high intra- and inter-tumor cellular and molecular heterogeneity with multiple subclones possessing distinct genetic determinants; 2) GSCs exhibit multiple redundant signaling pathways requiring simultaneous targeting of overlapping pathways. We have invented and biologically validated a novel tandem computational platform, GeneRep-nSCORE that integrates large-scale gene expression profiles with genomic changes to identify common founding alterations or master regulators of GSCs that span a large number, if not all, GSC subclones within and across GBM tumors. We discovered such a core set of four common master regulators in GCSs that are outstanding targets for clinical development. Expression of these four factors was sufficient to reprogram normal astrocytes to GSCs, whereas their depletion profoundly abrogated GSCs, and thus tumor development in vivo, in all eight lines of patient-derived GSCs of varied genetic and molecular backgrounds examined to date. The goal of this application is to develop a customized set of Adeno-associated virus (AAV)-based genetic tools to target the whole spectrum of GSCs (Phase I) for the purpose of delivering targeting constructs to deplete the four common master regulators responsible for malignant transformation and proliferation in GSCs (Phase II). The specific objectives of this proposal are: (i) using directed evolution and available combinatorial AAV capsid library, and for the first time, introducing a dynamic mode of administration of a library reagent over the time course of tumor progression, to greatly increase the probability of identifying novel AAV variants specifically targeting slow-, and fast-cycling GSCs in patient-derived xenograft models (PDX) (Phase I); (ii) To design and validate a panel of AAV vectors that express shRNAs targeting core master regulators of GSCs to identify leads for preclinical testing; (iii) To optimize modes of viral delivery, pharmacokinetics and pharmacodynamics parameters, and safety and toxicity in normal and PDX treated with lead targeting AAV cassettes; and (iv) Based on these results, tools and basic DMPK data created, to conduct preclinical efficacy studies in PDX treated with lead targeting AAV cassettes either alone or in combination with standard chemoradiotherapy (Phase II) to prepare for an investigative new drug application for clinical testing in patients with GBM, and for commercial development of this novel technology.

Public Health Relevance Statement:
Glioblastoma (GBM) is the most lethal form of adult human brain cancers. The goal of this proposal is to develop a customized set of viral vectors specifically targeting GBM stem-like cells. These novel viral vectors will express targeting constructs to deplete common master regulators responsible for malignant transformation and proliferation of these GBM stem cells such as tumor control and survival can be improved.

Project Terms:
Address; adeno-associated viral vector; Adult; Apoptotic; Astrocytes; base; Biological; Biological Assay; Biology; Capsid; CD44 gene; Cell surface; Cells; chemoradiation; clinical application; clinical development; Clinical Trials; Collaborations; combinatorial; computational platform; computerized tools; Custom; Data; Dependovirus; design; Development; Directed Molecular Evolution; DNA cassette; efficacy study; Environment; Exhibits; Expression Profiling; Florida; Flow Cytometry; Gene Expression; gene therapy; Genetic; Genetic Determinism; Genomics; Glioblastoma; Goals; Heterogeneity; improved; In Vitro; in vivo; in vivo evaluation; Individual; Injections; Inter-tumoral heterogeneity; interdisciplinary approach; knock-down; Lead; lead optimization; Libraries; Malignant - descriptor; Malignant neoplasm of brain; Modeling; Molecular; mouse model; new technology; novel; novel therapeutics; Pathway interactions; Patients; pharmacokinetics and pharmacodynamics; Phase; Platelet Factor 4; Population; Population Heterogeneity; pre-clinical; preclinical efficacy; Preclinical Testing; Probability; Process; programs; Radiation; Reagent; Recurrence; Regimen; research clinical testing; Safety; Serotyping; Signal Pathway; small hairpin RNA; Specificity; Stem cells; stem-like cell; Systems Biology; Technology; therapeutic development; Time; tool; Toxic effect; transduction efficiency; Treatment Failure; tumor; tumor progression; tumorigenesis; Universities; Variant; vector; Viral; Viral Vector; Xenograft Model; Xenograft procedure