SBIR-STTR Award

High serum urate levels (hyperuricemia) and subsequent monosodium urate crystal deposition cause gout, the most common inflammatory arthritis in men and postmenopausal women. Gout affects an estimated 9.2 million adults in the United States. Hyperuricemia is also a major complication in patients with tumor lysis syndrome. However, the management of hyperuricemia in gout patients is problematic. Currently, gout patients are treated with small molecule inhibitor urate-lowering drugs. Gout can progress to destructive arthropathy, deposition of monosodium urate (MSU) crystals (tophi), and nephropathy if urate- lowering drugs fail. For those patients, infusion of foreign uricases such as a recombinant fungal uricase (Raburicase) or recombinant mammalian uricase modified with polyethylene glycol (Pegloticase/Krystexxa) is indicated to control hyperuricemia and dissolve the MSU crystals. Unfortunately, the immunogenicity of the administered foreign uricase and the ubiquitous presence of anti-PEG antibodies in the population limit the therapeutic efficacy of Pegloticase/Krystexxa and prevent repeated treatment. We propose to develop a novel immune-escape uricase that is covered with a glycan shield and contains immune escape mutations. We have identified uricase from soil bacteria Terriglobus saanensis with excellent enzyme activity at physiological pH, and that can be expressed and secreted as an active enzyme in yeast and mammalian cells. Using Abzyme's maturation, surface display and secretion platform, a selected uricase will be displayed on yeast cell surfaces, subjected to continuous gene evolution and immune selection pressure. At the end of phase I, it is anticipated that as many as 2 unique functionally-active immune escape uricase variants with a significant reduction in or no binding to anti-uricase polyclonal antibodies will be isolated, expressed, purified, and characterized. In Phase II, the most promising molecules will be evaluated in animal models of induced gout pursuant to the submission of an IND application for the initiation of clinical trials. The novel uricase will offer a number of therapeutic advantages, including the facilitation of large-scale production and reduced immunogenicity.

Public Health Relevance Statement:
Narrative. We have proposed a novel platform to develop uricase genetic variants with the ability to escape immune surveillance for improved treatment of refractory gout. As the result of this project, an innovative "immune escape" engineering approach can be extended to engineer other biologics to reduce immunogenicity for effective treatment of human diseases.

Project Terms:
21+ years old; Adult Human; adulthood; Adult; Affect; Antibodies; Bacteria; Biological Assay; Assay; Bioassay; Biologic Assays; Biological Products; Biologic Products; Biological Agent; biologics; biopharmaceutical; biotherapeutic agent; Cell Culture Techniques; cell culture; cell cultures; Cell Separation; Cell Isolation; Cell Segregation; Cell Separation Technology; cell sorting; Cells; Cell Body; Affinity Chromatography; affinity purification; Clinical Trials; Complication; Diploidy; Diploid; Pharmaceutical Preparations; Drugs; Medication; Pharmaceutic Preparations; drug/agent; Engineering; Enzyme-Linked Immunosorbent Assay; ELISA; enzyme linked immunoassay; Enzymes; Enzyme Gene; Escherichia coli; E coli; E. coli; Evolution; Galactose; D-Galactose; Galactopyranose; Galactopyranoside; Genes; glycosylation; Metabolic Glycosylation; Gout; Immunoglobulin G; 7S Gamma Globulin; IgG; Immune system; Immunologic Surveillance; Immune Surveillance; Immunologic Surveillances; Immunological Surveillance; Immunological Surveillances; Immunosurveillance; arthropathies; Joint Diseases; arthropathic; arthropathy; joint disorder; Kidney Diseases; Nephropathy; Renal Disease; kidney disorder; renal disorder; Libraries; men; Molecular Weight; Mus; Mice; Mice Mammals; Murine; Mutagens; Genotoxins; genotoxic agent; Mutation; Genetic Alteration; Genetic Change; Genetic defect; genome mutation; Patients; Polyethylene Glycols; Macrogols; Polyethylene Oxide; Polyethyleneoxide; Polyoxyethylenes; Polysaccharides; Glycans; pressure; Production; Proteins; Oryctolagus cuniculus; Domestic Rabbit; Rabbits; Rabbits Mammals; Risk; medical schools; medical college; school of medicine; Signal Transduction; Cell Communication and Signaling; Cell Signaling; Intracellular Communication and Signaling; Signal Transduction Systems; Signaling; biological signal transduction; Soil; Stains; Staining method; T-Lymphocyte; T-Cells; thymus derived lymphocyte; Technology; Tumor Lysis Syndrome; United States; Universities; Urate Oxidase; Uricase; Uric Acid; Trioxopurine; Utah; Woman; Yeasts; Generations; Measures; CHO Cells; Chinese Hamster Ovary Cell; abzyme; Catalytic Antibodies; bases; base; improved; Surface; Clinical; Refractory; Phase; Variation; Variant; Physiologic; Physiological; Post-Menopause; Post-menopausal Period; Postmenopausal Period; after menopause; following menopause; past menopause; post-menopausal; postmenopausal; postmenopausal status; Postmenopause; Blood Serum; Serum; Individual; analog; enzyme activity; Letters; Therapeutic; polyclonal antibody; Genetic; Deposition; Deposit; Nature; Immune; Immunes; Crystal Formation; Crystal Deposition; System; Infusion procedures; Infusion; infusions; expression vector; Animal Model; Animal Models and Related Studies; model of animal; novel; Cell surface; Sorting; Hyperuricemia; uricacidemia; Urate; AICDA; AICDA protein; AID gene; AID protein; CDA2 protein; activation-induced deaminase; activation-induced cytidine deaminase; Molecular Interaction; Binding; preventing; prevent; Goat; Caprine Species; Goats Mammals; Data; Mammalian Cell; Mutate; Recombinants; in vivo; Monitor; Gene variant; allele variant; allelic variant; genomic variant; genetic variant; immunogenicity; intervention efficacy; therapeutic efficacy; therapy efficacy; Treatment Efficacy; scale up; Population; innovate; innovative; innovation; human disease; effective treatment; effective therapy; full scale manufacturing; large scale manufacturing; mass production; large scale production; Inflammatory Arthritis; small molecule inhibitor; DNA seq; DNAseq; DNA sequencing