Relaxin is a heterodimeric 53 amino acid peptide hormone that induces cardiovascular compliance and reproductive tissue remodeling during pregnancy and parturition. In addition to reproductive organs, the relaxin receptor, RXFP1, is also expressed in the liver, heart, lung, kidney, bone and skin. This broad tissue localization has led to the recognition that relaxin is a pleiotropic hormone with vasodilatory, antifibrotic, tissue remodeling, antiapoptotic, and anti-inflammatory properties in animal models. The efficacy of relaxin has been tested in human clinical trials in diseases ranging from acute and chronic heart failure, to fibrotic diseases of skin, lung, and liver; however, relaxin's short half-life and need for continual intravenous infusion have limited its clinical utility. While the rationale to treat fibrosis and cardiovascular diseases with relaxin remains high, better RXFP1 agonists must be developed that display longer serum half-lives and measurable pharmacodynamic readouts, while maintaining a safety profile commensurate with chronic RXFP1 agonist treatment. We have used Zebra Biologics' proprietary Protein-in-Protein (PiP) antibody technology to insert a single-chain relaxin construct into the complementarity-determining region (CDR) of an immunoglobulin G backbone. This technology has been used previously to engineer proteins and peptides with half-lives of days vs. minutes for the native molecules. A relaxin-PiP, H2-PiP, has now been engineered with an intrinsic potency comparable to recombinant relaxin in cellular assays. The objective of this proposal is to elucidate pharmacokinetic and pharmacodynamic properties of H2-PiP. We hypothesize that this long-acting relaxin-PiP agonist molecule will be a superior antifibrosis drug candidate compared to relaxin, allowing proof-of-concept efficacy and safety assessment with less frequent subcutaneous injections, thus obviating the need for continuous intravenous infusion.We submit a Phase 1 STTR grant application addressing the following Specific Aims (SA): SA1: Pharmacokinetic-pharmacodynamic (PK-PD) analysis of H2-PiP. The goal of SA1 is to determine the half-life and maximal active serum concentration of H2-PiP, and to correlate blood exposure with known pharmacodynamic markers of RXFP1 activation in the context of acute CCl4 toxicity. This correlation will allow us to establish estimates of dose and dose frequency for determining efficacy in models of liver fibrosis. SA2: Efficacy of H2-PiP in mouse models of hepatic fibrosis. The goal of SA2 is to determine the efficacy of H2-PiP in two mouse models of chronic liver fibrosis that display key molecular and histopathological features of human liver fibrosis: 1) CCl4 exposure and 2) high fat diet (HFD) treatment.Successful completion of these studies will set the stage for eventual clinical studies in a range of diseases where tissue fibrosis and hemodynamic pathologies are manifest. Public Health Relevance Statement Narrative Relaxin is a pleiotropic peptide hormone that acts through its GPCR receptor, RXFP1, to elicit vasodilatory, antifibrotic, tissue remodeling, antiapoptotic, anti-inflammatory, and angiogenic responses. Several clinical trials have been conducted with human relaxin to treat fibrosis and heart failure; however, success has been limited due, in part, to the short half-life of this peptide. The goal of this research proposal is to utilize Zebra Biologics' proprietary Protein-in-Protein technology that allows insertion of the relaxin peptide into an IgG backbone to create a long-acting relaxin agonist that can be tested for efficacy in rodent models of liver fibrosis, thus establishing a rationale for eventual clinical testing in human fibrotic diseases where the unmet medical need is high.
Project Terms: Amino Acids ; aminoacid ; Animals ; Anti-Inflammatory Agents ; Anti-Inflammatories ; Anti-inflammatory ; Antiinflammatories ; Antiinflammatory Agents ; antiinflammatory ; Antibodies ; Birth ; Parturition ; Blood ; Blood Reticuloendothelial System ; bone ; Carbon Tetrachloride ; Tetrachloromethane ; tetrachloro-methane ; Cardiovascular Diseases ; cardiovascular disorder ; Cardiovascular system ; Cardiovascular ; Cardiovascular Body System ; Cardiovascular Organ System ; Heart Vascular ; circulatory system ; Choline ; Clinical Research ; Clinical Study ; Clinical Trials ; Collagen ; Diet ; diets ; Disease ; Disorder ; Engineering ; Exhibits ; Extracellular Matrix ; Cell-Extracellular Matrix ; ECM ; Fatty acid glycerol esters ; Fats ; Fibrosis ; Goals ; Half-Life ; Heart ; Heart failure ; cardiac failure ; Congestive Heart Failure ; Cardiac Failure Congestive ; Heart Decompensation ; chronic heart failure ; hemodynamics ; Hormones ; Endocrine Gland Secretion ; Therapeutic Hormone ; Human ; Modern Man ; Immunoglobulin G ; 7S Gamma Globulin ; IgG ; Complementarity Determining Regions ; Complimentarity Determining Region ; Hypervariable Loop ; Hypervariable Regions ; Immunoglobulin Hypervariable Region ; Intravenous infusion procedures ; IV Infusion ; intravenous infusion ; Subcutaneous Injections ; subdermal injection ; Joints ; Kidney ; Kidney Urinary System ; renal ; Liver ; hepatic body system ; hepatic organ system ; Liver diseases ; Hepatic Disorder ; hepatic disease ; hepatopathy ; liver disorder ; Lung ; Lung Respiratory System ; pulmonary ; Inbred BALB C Mice ; BALB C Mouse ; BALB/c ; Mus ; Mice ; Mice Mammals ; Murine ; Pathology ; Peptides ; Drug Kinetics ; Pharmacokinetics ; Pharmacology ; Plasma ; Blood Plasma ; Plasma Serum ; Reticuloendothelial System, Serum, Plasma ; Pregnancy ; Gestation ; Production ; Protein Engineering ; genetic protein engineering ; protein design ; Proteins ; Reagent ; Relaxin ; Research ; Research Proposals ; Safety ; skin disorder ; Cutaneous Disorder ; Dermatoses ; Skin Diseases ; Skin Diseases and Manifestations ; cutaneous disease ; dermal disease ; dermal disorder ; Vertebral column ; Spinal Column ; Spine ; backbone ; Technology ; Testing ; Tissues ; Body Tissues ; Work ; relaxin receptor ; base ; Organ ; Hepatic ; Acute ; Chronic ; Clinical ; Phase ; Biological ; Medical ; Serum ; Blood Serum ; Liver Fibrosis ; fibrotic liver ; hepatic fibrosis ; Agonist ; Centrilobular hepatic necrosis ; Paracentral hepatic necrosis ; centrilobular liver necrosis ; centrilobular necrosis ; Zebra ; Frequencies ; subdermal ; subcutaneous ; experience ; Peptide Hormone Gene ; peptide hormone ; Receptor Protein ; receptor ; success ; Animal Models and Related Studies ; model of animal ; model organism ; Animal Model ; Toxicities ; Toxic effect ; Therapeutic Index ; G Protein-Complex Receptor ; G Protein-Coupled Receptor Genes ; GPCR ; G-Protein-Coupled Receptors ; Intoxication ; reproductive ; Pharmacodynamics ; Modeling ; Property ; response ; Skin ; Pharmaceutical Agent ; Pharmaceuticals ; Pharmacological Substance ; Pharmacologic Substance ; Address ; Dose ; Continuous Intravenous Infusion ; Grant Proposals ; Applications Grants ; Measurable ; Recombinants ; in vivo ; Cellular Assay ; cell assay ; research clinical testing ; Clinical Evaluation ; Clinical Testing ; clinical test ; Rodent Model ; Small Business Technology Transfer Research ; STTR ; Validation ; Pathologic ; Molecular ; Cirrhosis ; cirrhotic ; immunogenicity ; efficacy evaluation ; efficacy analysis ; efficacy assessment ; efficacy examination ; evaluate efficacy ; examine efficacy ; BZLF1 gene ; BZLF1 ; BZLF1 protein ; Epstein-Barr virus BZLF1 protein ; Epstein-Barr virus Zta protein ; ZEBRA protein ; Zta protein ; Zta transcription activator ; Outcome ; mouse model ; murine model ; antibody engineering ; nonalcoholic steatohepatitis ; NASH ; non-alcohol induced steatohepatitis ; non-alcoholic steato-hepatitis ; non-alcoholic steatohepatitis ; nonalcoholic steato-hepatitis ; efficacy testing ; drug candidate ; clinical investigation ; pharmacodynamic biomarker ; pharmacodynamic marker ; reproductive organ ; High Fat Diet ; Growth Factor ; Growth Agents ; Growth Substances ; Proteins Growth Factors ; efficacy study ; Injections ; safety assessment ; pharmacokinetics and pharmacodynamics ; PK/PD ; antifibrotic treatment ; antifibrotic therapy ;
