Funded Projects

Inhaled nitrous oxide, N₂O, is used in emergency departments in Europe to treat pain associated with sickle cell disease as well as for labor, painful fractures, and to manage serious gynecological pain. It is not a viable therapeutic option for home use for reasons such as poor dosing control, potential inhalation equipment issues, and variability in patient ventilation and lung absorption. This project seeks to optimize, characterize, and develop an oral formulation of N₂O that could be used by patients at home for unpredictable and severe episodes of pain associated sickle cell disease. Once developed, the new oral formulation of N₂O will be evaluated to determine whether it or an optimized version is ready for more clinical testing.

Taxanes are among the most effective chemotherapeutic agents and are frequently used in the treatment of early stage and metastatic breast cancer. However, they are known to produce a pain condition known as Chemotherapy-Induced Peripheral Neuropathic Pain (CIPNP). CIPNP is one of the primary reasons a patient receives a limited dose of taxane. No diagnostic tool exists to identify patients that will develop CIPNP in response to taxane therapy. Biomarker signatures associated with taxane-induced neuropathic pain will be developed to: 1) identify patients at risk for developing debilitating taxane neuropathic pain before chemotherapy is initiated; and 2) to identify patients already on treatment who are at risk of developing neuropathic pain and need dosing adjustments to prevent CIPNP symptoms. This biomarker signature will be used to detect CIPNP-susceptible patients early and personalize their taxane therapy to minimize CIPNP while optimizing the therapeutic taxane dosing.

Oral cancer pain is debilitating and difficult to treat, in part because even the most effective available pain remedies are limited by side effects. Opioid-based pain medications have several side effects including dependence and tolerance, in which the body gets used to a medicine so that either more medicine is needed or different medicine is needed. Another side effect is hyperalgesia, in which people taking opioids become more sensitive to certain painful stimuli and may misuse the drugs and risk addiction. This project will evaluate lab-made versions of cannabinoid molecules known to block pain signals in nerve cells, but which cannot enter the brain to cause neurological side effects. The research aims to advance promising versions of the molecules to testing in human research participants.

MNK-eIF4E signaling is activated in nociceptors upon exposure to pain or peripheral nerve injury, promoting cytokines and growth factors and increasing nociceptor excitability, which leads to neuropathic pain. Genetic or pharmacological inhibition of MNK signaling blocks and reverses nociceptor hyperexcitability as well as behavioral signs of neuropathic pain. A clinical phase drug for cancer shows strong specificity as an MNK inhibitor but requires optimization because MNK inhibition in the central nervous system (CNS) may lead to depression, an unacceptable side effect for a neuropathic pain drug. The research team plans a targeted medicinal chemistry and screening campaign directed at generating a MNK-inhibitor-based neuropathic pain treatment with the goal of restricting its CNS penetration while retaining potency, specificity, and in vivo bioavailability and efficacy.

There is increasing evidence that satellite glial cells (SGCs) surrounding neurons in the dorsal root ganglia modulate sensory processing and are important for chronic pain. Tissue inhibitor of metalloproteinase 3 (TIMP3) signaling occurs in SGCs and has unique plethoric functions in inhibiting matrix metalloproteinases, the tumor necrosis factor-?-converting enzyme, and the vascular endothelial growth factor receptor 2, all of which have been implicated in inflammation and pain. This study will test the hypothesis that expression of TIMP3 in SGCs is critical for the neuroimmune homeostasis in sensory ganglia, as well as for the development of pain, and therefore could be a novel therapeutic target for acute and chronic pain. Given the expression of TIMP3 in human SGCs and the strong validation of multiple small molecules targeting TIMP3 signaling, including FDA-approved drugs, in various animal models of pain and in cultured human SGCs, the successful completion of this research project has a high likelihood of rapid translation into therapeutic testing in inflammatory pain conditions that are a risk for opioid abuse.

This project will establish a rapid research pipeline for linking plant-derived compounds to nociception (pain) and to G Protein-Coupled Receptors (GPCRs) and ion channels in the druggable human genome. As more than 80% of these membrane proteins are conserved in the C. elegans nematodes, the study will screen for compounds and genes affecting nociception as well as to identify novel ligand-receptor pairs using this model organism. The study will test which understudied GPCRs and ion channels are involved in nociception as well as attraction or repulsion behaviors. This research has the potential to reveal novel ligand-receptor pairs that could serve as new entry points for improved or alternative pain treatments.

Current medications for chronic pain are largely ineffective and rely heavily on opioids, one contributor to the nation’s opioid crisis. The endocannabinoid system that consists of cannabinoid receptors (CB1R and CB2R) and their endogenous ligands is a natural pathway in the human body and has emerged as an alternative target for developing new pain medications with few side effects. Current molecules that bind to CB1R in the brain and spinal cord have psychoactive side effects, limiting their therapeutic use for treating chronic pain. This study aims to develop new molecules to bind to CB1R tightly and selectively, are metabolically stable, and are also unable to enter the brain.

The medication monomethyl fumarate, approved for treating multiple sclerosis, has pain-relieving properties, but it also has side effects that affect the digestive tract and decrease levels of white blood cells, a problem known as leukopenia. This project will limit the availability of monomethyl fumarate to areas in the central nervous system associated with pain. Targeting the delivery of this drug to pain-related regions may improve its safety profile for treating neuropathic pain.

Many non-opioid drugs target G Protein-Coupled Receptors (GPCRs), a family of proteins involved in many pathophysiological processes including pain, fail during clinical trials for unknown reasons. A recent study found GPCRs not only function at the surface of nerve cells but also within a cell compartment called the endosome, where their sustained activity drives pain. This study will build upon this finding and test whether the clinical failure of drugs targeting plasma membrane GPCRs is related to their inability to target and engage endomsomal GPCRs (eGPCRs). This study will use stimulus-responsive nanoparticles (NP) to encapsulate non-opioid drugs and selectively target eGPCR dyads to investigate how eGCPRs generate and regulate sustained pain signals in neuronal subcellular compartments. This study will also validate eGCPRs as therapeutic targets for treatment of chronic inflammatory, neuropathic and cancer pain. Using NPs to deliver non-opioid drugs, individually or in combinations, directly into specific compartments in nerve cells could be a potential strategy for new pain therapies.

Neuropathic pain is characterized by neuronal hyperexcitability and spontaneous activity, properties associated with activity of hyperpolarization-activated, cyclic nucleotide-regulated (HCN1-4) channels, the source of the pacemaker current, Ih. Inhibition of HCN1-mediated Ih elicits marked antihyperalgesia in multiple animal models of neuropathic pain, including models for direct nerve injury and chemotherapy-induced peripheral neuropathy, and does so with little or no disruption to either normal pain processing or baseline behaviors and activities. The overall objective is to develop a peripherally restricted HCN1 inverse-agonist as a therapeutic for neuropathic pain. Researchers have generated a novel small molecule that combines an antihyperalgesic HCN1 inhibitor with a motif that controls distribution and membrane presentation and is a potential non-opioid antihyperalgesic treatment for peripheral neuropathic pain.

Patients with severe, intractable chronic pain primarily receive treatment with opioids, and non-opioid treatment options are urgently needed. These patients may be candidates for treatment using other types of pain medications administered via intrathecal injection—that is, injection directly into the fluid-filled space between the membranes surrounding the brain and spinal cord. Intrathecal injection requires much lower medication doses than systemic administration. Centrexion Therapeutics Corporation seeks to develop CNTX-3100, a highly selective and highly potent novel small molecule that activates the nociception receptor (NOPr), for intrathecal administration using a pump approved by the U.S. Food and Drug Administration. In animal studies, such NOPr agonists had powerful analgesic effects when delivered directly to the spinal cord by intrathecal administration. CNTX-3100 has ideal properties for intrathecal delivery and in animal studies provided pain relief and a safety profile that was superior to intrathecally administered morphine. This project will scale up the drug, develop a formulation that ensures a stable product for intrathecal delivery, and conduct preclinical toxicity studies to prepare for a Phase 1 clinical trial.

Complex regional pain syndrome is one of the most disabling and difficult-to-treat chronic pain conditions. This project seeks to develop a novel, biological treatment for the condition using injected human bone marrow cells. that can form and repair skeletal tissues and control nervous and immune system activity. The research will determine the dose and source of clinical-grade bone marrow cells needed, toward the goal of submitting an Investigational New Drug Application to the U.S. Food and Drug Administration that will enable further clinical study.

Chronic pain severely reduces the quality of life and ability to work for millions of Americans. Because misuse of opioids for chronic pain treatment contributes to opioid addiction and opioid overdose, there is an urgent need to study novel non-opioid mechanisms, targets, and treatment strategies for chronic pain. Many ion channels control the flow of electrical signals in peripheral sensory neurons and are thus key targets for understanding and treating chronic pain. This project will conduct detailed studies to identify major ion channel-related molecular activities, targets, and treatment strategies for chronic pain. In particular, this research will explore the role of a specific ion channel (lysosomal mechanosensitive ion channel, orTmem63A) in neuropathic pain resulting from nerve injury.