Funded Projects

Although effective, current pharmacotherapies for opioid use disorder (OUD) present serious limitations. For example, methadone, a mu opioid receptor (MOP) full agonist, has significant abuse liability and causes withdrawal after chronic use, while buprenorphine (Bup), an MOP partial agonist and kappa opioid receptor (KOP) antagonist, produces limited respiratory depression and is less effective than methadone in reducing drug use, craving, and relapse. To address the limitation of currently available MATs, this project uses a phased plan that will fast-track the IND development of a next-generation medication for OUD based on small-molecule compounds targeting the nociception opioid receptor (NOP)—with no misuse or dependence liability—that have shown promising efficacy in reducing oxycodone intake in rhesus monkeys trained to self-administer, with efficacies similar to that of buprenorphine. The project’s ultimate goal is to file an IND application for an NOP agonist as a promising new approach to treat illicit and prescription OUD that may offer an alternative to buprenorphine.

This project proposes to develop novel Gpr151 antagonists to facilitate long-term abstinence in opioid-dependent individuals. Gpr151 is an orphan G-protein coupled receptor that is expressed almost exclusively in the medial habenula and co-localizes with ?-opioid receptors to regulate the inhibitory effects of opioids on habenular neurons. Mice with a null mutation in Gpr151 (Gpr151-/- mice) are resistant to the stimulant and rewarding effects of opioids and self-administer lower quantities of oxycodone. Based on this preliminary work, the study will seek to identify Gpr151 antagonists through a variety of methods and optimize them for potency, selectivity, drug metabolism, pharmacokinetics, and brain penetration properties. The study will evaluate effects of those with the most favorable drug-like physiochemical properties on electrophysiological responses of medial habenula to opioid drugs and assess the in vivo efficacy of these novel antagonists in wild-type and Gpr151-/- mice.

Neuropathic pain is a debilitating and complex medical condition for which safe and non-addictive treatment options are urgently needed. This project aims to develop new strategies for treating neuropathic pain by controlling the activity of transmembrane protein 97 (TMEM97), also known as the sigma 2 receptor, which has been shown to relieve pain in an animal model of neuropathic pain. The research aims to develop a new molecule that increases TMEM97 activity and is safe for human use, toward obtaining approval from the U.S. Food and Drug Administration for Phase I clinical testing. 

Addiction to opioids is related to the physiology of the brain’s dopamine-based reward system. As a modulator of dopaminergic systems, the neurotensin 1 receptor (NTR1) should be a molecular target for treating addictive disorders; however, few non-peptide brain penetrant neurotensin modulators have been identified, and orthosteric NTR1 ligands display side effects that have limited their clinical development. This group discovered a series of brain-penetrant NTR1 modulators, including a lead compound SBI-553, with a unique mechanism of action at NTR1. SBI-553 is an orally available, brain penetrant ?-arrestin biased allosteric modulator of NTR1, which shows efficacy in a range of addiction models and circumvents the clinically limiting side effects. While potentially high risk, the activity of SBI-553 has been validated in vitro and in vivo, and the initial safety profiling indicates no issues that would preclude further development. This study will develop SBI-553 as a treatment for opioid use disorder.

An increasing number of Americans use multiple drugs at the same time, and overdose deaths from stimulants have increased. However, there are no available treatments for stimulant use disorder. This project aims to develop new treatment (SBS-518) for cocaine use disorder. Previous research using animal models showed that SBS-518 decreases stimulant self-administration without being rewarding itself. The research will continue the development of SBS-518 toward testing in human research participants.

Although medications for opioid use disorder are effective and available, providers currently lack methods to monitor patients and thus inform improved dosing. This project will develop Strength Band Platform, an innovative artificial intelligence-based digital platform. The wearable device will collect patient physiological characteristics to detect relapse and withdrawal during treatment with medications for opioid use disorder in real-world settings. 

High rates of relapse and overdose deaths pose significant challenges to the treatment of Opioid Use Disorder (OUD). Anti-opioid immunotherapies (i.e., vaccines and monoclonal antibodies) have great potential to reduce long-term opioid use and overdose, with minimal risk of side effects, when used in conjunction with pharmacological treatments and/or behavioral therapies. The ability of an anti-opioid vaccine to induce antibodies that render an opioid less effective, or less rewarding, and protect from accidental overdose could provide an important therapeutic option for patients undergoing treatment for OUD. The goal of this collaborative study is to design, develop, and evaluate vaccines for use in the treatment of opioid use disorder

Even though pain is a nearly universal experience, objective measurements of pain remain difficult. Given that responding to the opioid crisis will require both better ways to manage pain and better ways to detect drug-seeking behavior, finding approaches to objectively measure pain is crucial. The goal of this project is to develop a product that will objectively measure pain using computer vision and machine learning technologies together with tablet-based self-reported pain data from patients for research or clinical purposes. The product will be low cost, involving one or two cameras to record the video and a computer to analyze the video in almost-real time, and will involve software that can be portable to ordinary personal computers and tablets. The project will capture facial expressions related to genuine pain and integrate it with patients’ self-reported pain data, in order to refine the product and create an objective measure of pain intensity that can be used in clinical settings and test its accuracy. This new tool has the potential to help rectify the poor pain outcomes that still plague Americans with opioid addiction, cancer, and other health conditions in many health care settings.

Postoperative pain is a major contributor to the current opioid epidemic. Novel objective measures capable of personalizing pain care will enhance medical precision in prevention and treatment of postoperative pain. This project seeks to discover and validate a novel biosignature of the human pain experience, based on underlying IL-1 family cytokine activity and associated brain endogenous opioid function, that is readily quantifiable and clinically translatable to prevention and treatment of postoperative pain states. Specific aims will assess whether the novel biosignature will predict 1) experimentally induced pain during an experimental nociceptive pain challenge; 2) postoperative pain states with accuracy >75%, accounting for a wide range of variance in the human pain experience; and 3) postoperative pain states in an expanded clinically enriched sample.

Neuropathic pain conditions are exceedingly difficult to treat, and novel non-opioid analgesics are desperately needed. Receptomic and unbiased transcriptomic approaches recently identified the orphan G-protein coupled receptor (oGPCR), GPR160, as a major oGPCR whose transcript is significantly increased in the dorsal horn of the spinal cord (DH-SC) ipsilateral to nerve injury, in a model of traumatic nerve-injury induced neuropathic pain caused by constriction of the sciatic nerve in rats (CCI). De-orphanization of GPR160 led to the identification of cocaine- and amphetamine-regulated transcript peptide (CARTp) as a ligand which activates pathways crucial to persistent pain sensitization. This project will test the hypothesis that CARTp/GPR160 signaling in the spinal cord is essential for the development and maintenance of neuropathic pain states. It will also validate GPR160 as a non-opioid receptor target for therapeutic intervention in neuropathic pain, and characterize GPR160 coupling and downstream molecular signaling pathways underlying chronic neuropathic pain.

We propose to develop a safe and effective nonopioid analgesic to treat neuropathic pain that targets an isoform of the voltage-gated sodium ion channel, NaV1.7. Voltage-gated sodium channels are involved in the transmission of nociceptive signals from their site of origin in the peripheral terminals of DRG neurons to the synaptic terminals in the dorsal horn. NaV1.7 is the most abundant tetrodotoxin-sensitive sodium channel in small diameter myelinated and unmyelinated afferents, where it has been shown to modulate excitability and set the threshold for action potentials. Development of systemic NaV1.7 inhibitors has been complicated by the challenge of achieving selectivity over other NaV isoforms expressed throughout the body. We have discovered a series of potent, state-independent NaV1.7 inhibitors that exhibit >1000-fold selectivity over other human isoforms. Work conducted under this program will support advancement of a lead candidate into clinical development as a therapeutic for neuropathic pain.

Chemotherapy-induced peripheral neuropathy (CIPN) is detected in 64% of cancer patients during all phases of cancer. CIPN can result in chemotherapy dose reduction or discontinuation, and can also have long-term effects on the quality of life. Taxanes (like Paclitaxel) may cause structural damage to peripheral nerves, resulting in aberrant somatosensory processing in the peripheral and/or central nervous system. Dorsal root ganglia (DRG) sensory neurons as well as neuronal cells in the spinal cord are key sites in which chemotherapy induced neurotoxicity occurs. T-type Ca2+ channels are critical determinants of increased neuronal excitability and neurotransmission accompanying persistent neuropathic pain. Though Cav3.2 has been targeted clinically with small molecule antagonists, no drugs targeting these channels have advanced to phase II human clinical trials. This proposal aims to explore multicomponent reaction products, for the rapid identification of potent and selective T-type Ca2+ channel antagonists. The work proposed here is the first step in developing non-opioid pain treatments for CIPN. The team anticipates success against paclitaxel-induced chronic pain will translate into other chronic pain types as well, but CIPN provides focus for early stage proof-of-concept.

Chronic post-traumatic headache (PTH) is highly debilitating, poorly understood, and difficult to treat. This project aims to identify proteins located in the membrane of certain neurons that are critical for the development, maintenance, and/or resolution of PTH. These proteins may be targets for novel treatment approaches that are nonaddictive and have minimal side effects.