This Phase II SBIR proposal will support our ongoing drug discovery program designed to develop and validate small molecule inhibitors of a novel drug target regulating platelet production in humans. The scope of work builds on strong genetic and biochemical evidence linking redox-dependent enzymatic activity of biliverdinIX? reductase (BLVRB) in a previously-uncharacterized regulatory pathway of megakaryocyte development and enhanced platelet production. In silico virtual screening with our novel scoring function led to the identification of ~20 compounds predicted to inhibit the redox activity of BLVRB. Biochemical and cell-based assays validated four of these compounds as potent inhibitors of the enzyme. A complementary crystallographic assay led to the identification of two additional compounds with increased potency towards BLVRB. We will employ medicinal and computational chemistry to optimize our hit compounds to develop lead compounds with improved potency and selectivity for BLVRB. These compounds will be further characterized using in vitro hematopoietic assays and follow up in vivo animal studies to show improved efficacy in comparison to our current hit compounds. Long-term success of this project is predicated on synergistic expertise in computational chemistry, platelet biochemistry, crystallography, and drug discovery. Successful completion of the research proposed in this grant has fundamental relevance to commercial development of a new class of platelet enhancing compounds functioning independently of the known thrombopoietin (TPO)/c-MPL receptor axis. Compound development and target validation provide a highly innovative strategy that would theoretically bypass toxicities associated with direct TPO/c-MPL agonists currently in clinical use (such as platelet activation, thromboembolic complications, and bone marrow fibrosis), while generating first-in-class redox inhibitors for further pre-clinical development. PHS 398/2590 (Rev. 06/09) Page Continuation Format Page
Public Health Relevance Statement: Program Director/Principal Investigator (Last, First, Middle): NESBITT, Natasha M.. PROJECT NARRATIVE/PUBLIC HEALTH RELEVANCE Human blood platelets stop bleeding, and low platelet counts cause life-threatening hemorrhage. Approaches to temporarily correct low platelet counts include platelet transfusions from donors (difficult to obtain and costly), and medications which are known to be associated with platelet activation, blood clotting, worsening platelet counts and bone marrow scarring. The approach taken in this Phase II SBIR grant builds on our efforts to develop a new class of compounds for a highly novel drug target identified in our laboratory that regulates platelet counts in humans. The applicant small business organization Blood Cell Technologies was specifically developed for early stage R&D focusing on commercial development of diagnostics and therapeutics important for human blood diseases. A drug development program targeting a distinct oxidation reduction reaction represents an innovative platelet-enhancing strategy unrelated to previous drug targets. The scope of work builds on strong genetic evidence linking the enzymatic function to enhanced platelet counts in humans, identifies a novel pharmacologic target for development, and represents a new mechanism of action that may have broader implications for redox biology in blood formation. Successful completion of the research has fundamental relevance to commercial development of a new class of compounds that enhance platelet counts in humans. PHS 398/2590 (Rev. 06/09) Page Continuation Format Page
Project Terms: efficacy evaluation; efficacy analysis; efficacy assessment; efficacy examination; evaluate efficacy; examine efficacy; innovation; innovate; innovative; chemotherapy; induced pluripotent stem cell; iPS; iPSC; iPSCs; new therapeutic target; new drug target; new druggable target; new pharmacotherapy target; new therapy target; novel drug target; novel druggable target; novel pharmacotherapy target; novel therapeutic target; novel therapy target; public health relevance; FDA approved; Drug Targeting; small molecule inhibitor; nanomolar; nano-molar; novel drug class; new drug class; preclinical development; pre-clinical development; lead optimization; lead candidate; in vivo evaluation; in vivo testing; blood formation; in silico; virtual screening; virtual screenings; thrombotic complications; thromboembolic complications; thrombosis complications; absorption; Alleles; Allelomorphs; Animals; inhibitor/antagonist; inhibitor; Biliverdine; Biliverdin; Dehydrobilirubin; Ooecyan; Uteroverdine; Biochemistry; Biological Chemistry; Biological Assay; Assay; Bioassay; Biologic Assays; Biology; Blood Cells; Peripheral Blood Cell; Blood coagulation; Blood Clotting; Blood Platelets; Marrow platelet; Platelets; Thrombocytes; Bone Marrow; Bone Marrow Reticuloendothelial System; Cells; Cell Body; Pharmaceutical Chemistry; Medicinal Chemistry; Pharmaceutic Chemistry; Cicatrix; Scars; Clinical Research; Clinical Study; Crystallography; Crystallographies; Pharmaceutical Preparations; Drugs; Medication; Pharmaceutic Preparations; drug/agent; Grant; Hematological Disease; Blood Diseases; Hematologic Diseases; Hematological Disorder; blood disorder; Hemorrhage; Bleeding; blood loss; Human; Modern Man; In Vitro; Laboratories; Lead; Pb element; heavy metal Pb; heavy metal lead; Megakaryocytes; Blood megakaryocyte; Megalokaryocyte; Metabolism; Intermediary Metabolism; Metabolic Processes; Mus; Mice; Mice Mammals; Murine; Myelofibrosis; Bone Marrow Fibrosis; Myelosclerosis; Oxidation-Reduction; Redox; oxidation reduction reaction; Oxidoreductase; Dehydrogenases; Oxidoreductase Gene; Reductases; Drug Kinetics; Pharmacokinetics; Pharmacology; Phenotype; Platelet Activation; Platelet Count measurement; Blood Platelet Count; Blood Platelet Number; Platelet Count; Platelet Number; Production; Program Development; Publications; Scientific Publication; Reagent; Research; research and development; Development and Research; R & D; R&D; Safety; Stress; Structure-Activity Relationship; chemical structure function; structure function relationship; Technology; Thrombocytopenia; Thrombopenia; Thrombopoietin; MGDF; MGDF Factor; Megakaryocyte Colony Stimulating Factor; Megakaryocyte Growth and Development Factor; Myeloproliferative Leukemia Virus Oncogene Ligand; Thrombocytopoiesis-Stimulating Factor; Thrombocytopoietin; c-mpl Ligand; mpl Ligand; Work; Interleukin-11; IL-11; IL11; Businesses; Platelet Transfusion; Blood Platelet Transfusion; Plts; interleukin-11 receptor; IL-11R; base; improved; Clinical; Phase; Biochemical; Link; Chemicals; Excretory function; excretion; Thrombopoiesis; Thrombocytopoiesis; Hematopoietic; hemopoietic; Recovery; Agonist; Therapeutic; Genetic; Exposure to; tool; Diagnostic; Life; programs; meetings; mutant; Receptor Protein; receptor; success; Toxicities; Toxic effect; Phenocopy; novel; validation studies; Bypass; MPLV; Mouse Homolog of Myeloproliferative Leukemia Virus; Myeloproliferative Leukemia Virus Oncogene; TPOR; Thrombopoietin Receptor; MPL gene; Pharmacodynamics; Modeling; Property; computational chemistry; drug development; Enzyme Antagonist; Enzyme Inhibitor; Enzyme Inhibitor Agent; Enzyme Inhibitor Drugs; drug discovery; Pharmaceutical Agent; Pharmaceuticals; Pharmacological Substance; Pharmacologic Substance; Metabolic Pathway; Affinity; Data; Regulatory Pathway; in vivo; Small Business Innovation Research Grant; SBIR; Small Business Innovation Research; Validation; Preparation; Principal Investigator; Characteristics; follow-up; Active Follow-up; active followup; follow up; followed up; followup; Development; developmental; Pathway interactions; pathway; pre-clinical; preclinical; cost; design; designing
