SBIR-STTR Award

This application “High throughput screen to identify small molecule analgesics targeting nNOS-NOS1AP protein-protein interactions” addresses the critical need for more effective medications to treat pain and, in particular chronic and neuropathic pain. Pain is the single-most common reason Americans access the health care system. Chronic pain affects ~116 million people in the USA. Current pain medications such as NSAIDS, steroids, opiates and gabapentin analogues have documented side effects, are ineffective in neuropathic pain or work only in subsets of patients. Chronic pain results in socioeconomic costs estimated at $560-635 billion annually. Activation of NMDA receptors (NMDAR) induces neuronal cell death and mediates central nervous system sensitization, which is implicated in the development and maintenance of pathological pain. NMDA induced excitotoxicity depends on formation of a multi-protein cascade complex at the receptor. Activation of the NMDAR leads to the recruitment of neuronal nitric oxide synthase (nNOS) by the post-synaptic density 95 protein (PSD95) to the signaling pathways which ultimately leads to neuronal cell death. Peptide disruptors of the NMDAR tripartite complex have been shown to be efficacious in stroke models and may also have fewer side effects than broad NMDAR antagonists. Small molecule inhibitors targeting the complex have potential as effective analgesics without the side effects associated with broad inhibition of NMDAR. A direct downstream effector of the NMDAR complex is nNOS-NOS1AP. A compound inhibiting this complex will likely be efficacious against stroke, neuropathic pain and other chronic neurological diseases precipitated by excitotoxicity. Anagin and its research partners at Indiana University have established a robust, high quality high-throughput assay to identify small molecule disruptors of nNOS-NOS1AP interaction, validated the assay and our approach in a pilot 10,000 compound small molecule library screen. In addition, Anagin has secondary in vitro selectivity and cell-based efficacy assays to perform hit-to-lead compound characterization as well as established collaborations to perform preclinical validation. In this Phase I SBIR program, the team will run an extensive small molecule screen to identify new druggable inhibitors with novel scaffolds that target nNOS-NOS1AP. Anagin will complete a small chemistry effort and initial administration- distribution-metabolism-excretion/toxicity studies to determine which compound series to advance as a lead molecule in a Phase II SBIR program for the treatment of chronic and neuropathic pain.

Public Health Relevance Statement:
Project Narrative Pain is the single-most common reason Americans access the health care system and affects ~116 million people in the U.S.A. Current pain medications such as NSAIDS, steroids, opiates and gabapentin have side effects, are ineffective in neuropathic pain or only work in some of the patients that need pain control. In this SBIR, Anagin will screen a small molecule library and identify new lead compounds that will be effective again pain, especially neuropathic pain, with fewer side effects than current treatments.

Project Terms:
abstracting; Address; Adverse effects; Affect; American; Analgesics; analog; base; Binding; Biochemical; Biological Assay; Biology; Cells; Chemicals; Chemistry; Chronic; chronic neuropathic pain; chronic pain; Collaborations; Complex; cost; density; Development; drug discovery; excitotoxicity; Excretory function; Exhibits; expectation; experience; Finland; Future; gabapentin; Goals; Healthcare Systems; high throughput screening; In Vitro; Indiana; inhibitor/antagonist; interest; Lead; Maintenance; Mediating; medical schools; Metabolism; Modeling; N-Methyl-D-Aspartate Receptors; N-Methylaspartate; Nerve Degeneration; nervous system disorder; Neuraxis; neuron loss; Nitric Oxide Synthase Type I; NMDA receptor antagonist; novel; Opiates; Pain; Pain management; painful neuropathy; Pathologic Processes; Pathway interactions; patient subsets; Patients; Peptides; Pharmaceutical Preparations; Pharmacologic Substance; pharmacophore; Phase; Physiological; pre-clinical; Prodrugs; programs; Property; protein complex; protein phosphatase inhibitor-2; protein protein interaction; Proteins; receptor; Receptor Signaling; Research; Research Personnel; Running; scaffold; screening; Series; Signal Pathway; Small Business Innovation Research Grant; small molecule; small molecule inhibitor; small molecule libraries; socioeconomics; Steroids; stroke; Structure-Activity Relationship; Synapses; Testing; Therapeutic; Toxic effect; treatment program; United States National Institutes of Health; Universities; Validation; Work

This application, "Development of novel small molecule analgesics modulating the nNOS-NOS1AP protein- protein interaction," addresses the critical need for more effective medications to treat chronic neuropathic pain affecting ~116 million people in the United States. Current pain medications such as NSAIDS, steroids, opiates and gabapentin analogs have documented and often severe side effects, are poorly effective in neuropathic pain and provide adequate relief only in limited subsets of patients. Because of its high prevalence and poor treatment options, chronic pain results in socioeconomic costs estimated at $560-635 billion annually in the US. Activation of NMDA receptors (NMDARs) mediates central nervous system sensitization, which is implicated in the development and maintenance of neuropathic pain. NMDA-mediated central sensitization depends on formation of a multi-protein cascade complex at the receptor that includes post-synaptic density 95 protein (PSD95), neuronal nitric oxide synthase (nNOS) and NOS1 adaptor protein (NOS1AP). A peptide disruptor of the NMDAR multi-protein complex is efficacious in preclinical stroke and pain models and is currently in clinical trials for ischemic stroke. Small molecule inhibitors targeting this complex have the potential to be effective analgesics without the side effects associated with broad inhibition of NMDARs. A direct downstream effector of the NMDAR complex is nNOS-NOS1AP. A compound inhibiting this complex will likely be efficacious against neuropathic pain, stroke and chronic neurological diseases precipitated or exacerbated by excessive NMDAR activity. In the funded Phase I SBIR program, our team ran an extensive small molecule high-throughput screen to identify inhibitors of the nNOS-NOS1AP protein-protein interaction. After confirmation of activity, selectivity and initial administration-distribution-metabolism-excretion/toxicity (ADME/T) studies on the top leads, we chose two drug-like, selective nNOS-NOS1AP inhibitors with distinct scaffolds for in vivo studies. Both inhibitors are efficacious in pain models. We initiated a small chemistry effort on one chemical series, identifying regions for selectivity and potency. In the current proposal, a traditional drug medicinal chemistry approach will be used to design and develop novel analogs with improved pharmacokinetic properties and potency compared to the parent compounds. Anagin and its research partners at AMRI and Indiana University will advance at least one series through early lead optimization studies. In addition to improving potency and ADME/T properties, we will demonstrate that the best analogs are acting on the intended target in cells, validate their activity in two preclinical pain models and assess their safety profile in key behavioral in vivo models. Compounds that do not meet our set criteria will not be advanced. We anticipate that our lead compound would have a better therapeutic index than current pain medications. We have a team of business, chemistry, biology and in vivo scientific experts in place to advance these series towards lead optimization and into the clinic for the treatment of chronic neuropathic pain.

Thesaurus Terms:
Adaptor Signaling Protein; Address; Adverse Effects; Affect; American; Analgesics; Analog; Base; Behavioral; Binding; Biochemical; Biological Assay; Biology; Brain; Businesses; Cells; Central Sensitization; Chemicals; Chemistry; Chronic Neurologic Disease; Chronic Neuropathic Pain; Chronic Pain; Clinic; Clinical Trials; Complex; Cost; Density; Design; Development; Drug Kinetics; Drug Targeting; Efficacy Testing; Excretory Function; Exhibits; Formalin; Freund's Adjuvant; Funding; Gabapentin; Goals; Grant; Healthcare Systems; High Prevalence; High Throughput Screening; Hyperalgesia; Improved; In Vitro; In Vivo; In Vivo Model; Indiana; Inhibitor/Antagonist; Ischemic Stroke; Lead; Lead Optimization; Lead Series; Ligation; Maintenance; Manuscripts; Mediating; Membrane; Metabolism; Modeling; Mouse Model; Multiprotein Complexes; N-Methyl-D-Aspartate Receptors; N-Methylaspartate; Nerve Degeneration; Neuraxis; Neurons; Neuropsychiatry; Nitric Oxide Synthase Type I; Non-Steroidal Anti-Inflammatory Agents; Nos1 Gene; Novel; Opioid; Pain; Pain Behavior; Pain Management; Pain Model; Painful Neuropathy; Parents; Pathologic Processes; Patient Subsets; Patients; Penetration; Peptides; Persistent Pain; Pharmaceutical Chemistry; Pharmaceutical Preparations; Phase; Plasma; Pre-Clinical; Pre-Clinical Model; Prevent; Programs; Property; Protein Protein Interaction; Proteins; Receptor; Recruit; Research; Role; Safety; Safety Study; Scaffold; Sciatic Nerve; Series; Signal Pathway; Signal Transduction; Small Business Innovation Research Grant; Small Molecule; Small Molecule Inhibitor; Socioeconomics; Steroids; Stroke; Stroke Model; Structure-Activity Relationship; Synapses; Therapeutic; Therapeutic Index; Tool; Toxic Effect; Treatment Efficacy; Triage; United States; Universities; Ventilatory Depression; Work;