Triple negative breast cancer (TNBC) has few treatments, and patients have a poor prognosis. Checkpointinhibitors (e.g., anti-PD-1 antibodies) represent a promising new therapeutic strategy, and two recent clinicaltrials demonstrate that TNBC patients may benefit. However, only a fraction of patients responded indicating thatadditional combination therapy with anti-PD-1 is needed. Strand Therapeutics developed a synthetic self-replicating mRNA (repRNA) for use with anti-PD-1. We achieve tumor-directed expression by encapsulating anddirectly injecting the in vitro transcribed repRNA with our fully developed lipid nanoparticle (LNP) into the tumor.The entire repRNA manufacturing process is done in vitro, giving us advantages over virus-based approachesthat require mammalian cell culture. Once in the tumor microenvironment (TME), the repRNAs express a potentengineered form of the interleukin 12 (IL-12) fusion protein (IL-12-lumican) to stimulate the anti-tumor activity ofNK cells and CD8 T cells in TNBC lesions. The IL-12-lumican fusion protein reduces the risk of systemic toxicityand enhanced activity by retaining IL-12 within the TME via a collagen-binding domain (lumican). In addition,repRNA expression and replication have advantages over the short expression duration of modified RNA(modRNA), and repRNA stimulates various pattern recognition receptors such as TLRs, RIG-I, and MDA-5 toupregulate type-I interferon. Furthermore, Strand Therapeutics' proprietary LNP not only efficiently deliversmRNA to cells but also uniquely synergizes with the repRNA to induce oncolytic effects (immunogenic cell death).These additional inflammatory cues facilitate turning a "cold" TME to one that will respond to anti-PD-1 therapy.In this proposal, we will determine whether tumoral injection of repRNA IL-12-lumican can effectively overcomeinsufficient immune activation in the TME and augment responses to anti-PD-1 therapy in TNBC. In Aim 1 wewill demonstrate that in TNBC cells repRNAs have more sustained transgene expression and greater type I IFNinduction than modRNAs. In Aim 2 we will demonstrate that repRNAs in human cell line-derived xenograft (CDX)and patient-derived xenografts (PDX) have greater sustained expression than modRNAs. In Aim 3 we willdemonstrate efficacy and superiority of repRNA IL-12-lumican over modRNA IL-12-lumican treatment (incombination with anti-PD-1) in vivo in syngeneic mouse models of TNBC and ex vivo in primary explants fromTNBC patients. These studies will provide proof of concept data that Strand Therapeutics' approach using self-replicating mRNA encoding IL-12 in combination with PD-1 antibody blockade is effective at reducing TNBCtumor volume. PROJECT NARRATIVE
Strand Therapeutics is developing a novel and exciting new replicating RNA (repRNA) therapy for triple negative
breast cancer (TNBC). Lipid nanoparticles deliver repRNAs directly to the tumor microenvironment (TME) which
sustainably express cytokines to increase TME immunogenicity and ultimately, the efficacy of anti-PD-1 therapy. Interferon-alpha ; (IFN) α ; (IFN)-α ; (IFN)α ; Alferon ; IFN Alpha ; IFN α ; IFN-α ; IFNa ; IFNα ; Interferon Alfa-n3 ; Interferon-α ; Leukocyte Interferon ; Lymphoblast Interferon ; Lymphoblastoid Interferon ; Alphavirus ; Alpha Virus ; Group A Arboviruses ; Cell Culture Techniques ; cell culture ; Cell Line ; CellLine ; Strains Cell Lines ; cultured cell line ; Cells ; Cell Body ; Clinical Trials ; Collagen ; Combined Modality Therapy ; Multimodal Therapy ; Multimodal Treatment ; combination therapy ; combined modality treatment ; combined treatment ; multi-modal therapy ; multi-modal treatment ; Cues ; Engineering ; Enzyme-Linked Immunosorbent Assay ; ELISA ; Flow Cytometry ; Flow Cytofluorometries ; Flow Cytofluorometry ; Flow Microfluorimetry ; Flow Microfluorometry ; flow cytophotometry ; Human ; Modern Man ; Immunotherapy ; Immune mediated therapy ; Immunologically Directed Therapy ; immune therapeutic approach ; immune therapeutic interventions ; immune therapeutic regimens ; immune therapeutic strategy ; immune therapy ; immune-based therapies ; immune-based treatments ; immuno therapy ; In Vitro ; Interferon Type I ; Interferons ; IFN ; Natural Killer Cells ; Cytotoxic cell ; K lymphocyte ; NK Cells ; Kinetics ; Luciferases ; Luciferase Immunologic ; melanoma ; Malignant Melanoma ; Mus ; Mice ; Mice Mammals ; Murine ; Patients ; Risk ; RNA ; Non-Polyadenylated RNA ; RNA Gene Products ; Ribonucleic Acid ; RNA-Directed RNA Polymerase ; EC 2.7.7.48 ; RNA Replicase ; RNA-Dependent RNA Polymerase ; Messenger RNA ; mRNA ; Stains ; Staining method ; Genetic Transcription ; Gene Transcription ; RNA Expression ; Transcription ; Virus ; cytokine ; Measures ; Interleukin-12 ; Edodekin Alfa ; IL-12 ; IL12 ; NKSF ; Natural Killer Cell Stimulatory Factor ; lumican ; Paclitaxel ; Anzatax ; Asotax ; Bristaxol ; Paclitaxel (Taxol) ; Praxel ; Taxol ; Taxol A ; Taxol Konzentrat ; Chimeric Proteins ; Chimera Protein ; Fusion Protein ; base ; improved ; Encapsulated ; Reporter Genes ; Ensure ; Lesion ; Binding Proteins ; Ligand Binding Protein ; Ligand Binding Protein Gene ; Protein Binding ; bound protein ; CD8-Positive T-Lymphocytes ; CD8 Cell ; CD8 T cells ; CD8 lymphocyte ; CD8+ T cell ; CD8+ T-Lymphocyte ; CD8-Positive Lymphocytes ; T8 Cells ; T8 Lymphocytes ; Therapeutic ; Inflammatory ; Reporter ; Tumor Volume ; Heterograft ; Heterologous Transplantation ; Xenograft ; Xenotransplantation ; xeno-transplant ; xeno-transplantation ; Xenograft procedure ; meetings ; synergism ; Induction Therapy ; NEOADJ ; Neoadjuvant ; Neoadjuvant Treatment ; Neoadjuvant Therapy ; complete response ; In complete remission ; novel ; Human Cell Line ; response ; Molecular Interaction ; Binding ; RNA replication ; PD 1 ; PD-1 ; PD1 ; programmed cell death 1 ; programmed death 1 ; sle2 ; systemic lupus erythematosus susceptibility 2 ; programmed cell death protein 1 ; Tumor Load ; Tumor Burden ; Data ; breast tumor cell ; Breast Cancer Cell ; Mammalian Cell ; in vivo ; Oncolytic ; Pathologic ; Adjuvant ; Development ; developmental ; Pattern recognition receptor ; triple-negative invasive breast carcinoma ; TNBC ; triple-negative breast cancer ; tumor microenvironment ; cancer microenvironment ; immunogenicity ; manufacturing process ; transgene expression ; chemotherapy ; mouse model ; murine model ; tumor ; novel therapeutic intervention ; new therapeutic approach ; new therapeutic intervention ; new therapeutic strategies ; new therapy approaches ; novel therapeutic approach ; novel therapeutic strategies ; novel therapy approach ; standard of care ; Regimen ; immune activation ; Immune Cell Activation ; adaptive immunity ; Breast Cancer cell line ; Breast tumor cell line ; Breast Cancer Patient ; Breast Tumor Patient ; 4T1 ; programmed cell death ligand 1 ; B7-H1 ; B7H1 ; CD274 ; PD-L1 ; PDL-1 ; PDL1 ; Programmed Cell Death 1 Ligand 1 ; Programmed Death Ligand 1 ; programmed cell death protein ligand 1 ; systemic toxicity ; patient subsets ; patient subgroups ; patient subpopulations ; patient subtypes ; in vivo imaging system ; IVIS SpectrumCT ; IVIS imaging ; IVIS optical imaging ; IVIS spectral imaging ; IVIS spectrum ; IVIS system ; Immune checkpoint inhibitor ; Checkpoint inhibitor ; immune check point inhibitor ; anti-PD1 antibodies ; PD-1 antibody ; PD1 antibody ; anti-PD-1 Ab ; anti-PD-1 antibodies ; anti-PD-1 monoclonal antibodies ; anti-PD1 Ab ; anti-PD1 monoclonal antibodies ; anti-programmed cell death protein 1 antibodies ; anti-PD1 therapy ; PD-1 antibody therapy ; PD-1 therapy ; PD1 antibody therapy ; PD1 based treatment ; aPD-1 therapy ; aPD-1 treatment ; aPD1 therapy ; aPD1 treatment ; anti-PD-1 therapy ; anti-PD-1 treatment ; anti-PD1 treatment ; anti-programmed cell death 1 therapy ; anti-programmed cell death protein 1 therapy ; programmed cell death protein 1 therapy ; immunogenic cell death ; immunogenic apoptosis ; anti-tumor immune response ; antitumor immune response ; Injections ; anti-PD-1 ; aPD-1 ; aPD1 ; anti programmed cell death 1 ; anti-PD1 ; anti-programmed cell death protein 1 ; antiPD-1 ; antiPD1 ; αPD-1 ; αPD1 ; patient response ; patient specific response ; responsive patient ; imager ; nanoparticle delivery ; nano particle delivery ; nanoparticle delivered ; lipid nanoparticle ; PD-L1 blockade ; PDL1 blockade ; anti-PD-L1 blockade ; pembrolizumab ; Keytruda ; patient derived xenograft model ; PDX model ; Patient derived xenograft ; Prognosis ;
