Funded Projects

Low back pain (LBP) is one of the most common reasons for all physician visits in the U.S. The financial costs associated with the care of LBP are staggering. The treatments for chronic low back pain (cLBP) are far from satisfactory, and opioids are often prescribed with varying degrees of success. This study builds on prior work suggesting that auricular transcutaneous vagus nerve stimulation (tVNS), a non-invasive therapeutic, can significantly reduce symptoms of chronic pain and common comorbidities of chronic pain, such as depression and anxiety. This proposal aims to investigate the treatment effect and underlying mechanism of tVNS on chronic low back pain. Patients with chronic low back pain will be randomized to either real or sham tVNS treatment for 1 month, with a 3-month follow-up. This study, if successful, could provide new treatment options for chronic low back pain and reduce the use of opioid analgesics in chronic pain management.

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.

There is a need to develop a mu-opioid receptor (MOR) treatment with enhanced therapeutic effects and reduced undesirable effects. Recently, several highly selective and potent MOR modulators have been identified as novel leads for opioid use disorder treatment. They all showed more promising pharmacological profiles compared to other known drugs in this category. The current proposal will focus on further development of these leads for preclinical IND-enabling studies and dynamic drug discovery and development pipeline construction. This project plans to further validate therapeutic profiles of the current leads with self-administration and pharmacokinetic studies and expand the small-molecule library to build a dynamic drug discovery and development pipeline. Preclinical IND-enabling studies on the identified lead(s) will be conducted, and in vivo pharmacokinetics and pharmacodynamics profiles of the new hits will be compared with current leads to define the next generation of lead compound(s).

Naltrexone (NTX) has proven to be an important, safe, and effective therapy for helping patients overcome opioid use disorders (OUD) and for preventing overdose. Unfortunately, the therapeutic potential of NTX has been blunted by poor adherence. To combat this issue, a system must be developed to deliver NTX for longer durations than currently available and with a more patient-friendly format. To address this problem, we will develop a long-acting and bioabsorbable NTX subcutaneous implant for the treatment of OUD. The proposed research will (a) determine the optimal chemical preparation of NTX inside the implant, (b) optimize the composition and porosity of the drug delivery substrate, and (c) refine the surgical procedure and instrumentation to be used during implantation. Once the safety and efficacy of this novel NTX implant is established, we will conduct the necessary clinical trials. The proposed study is highly relevant to and complementary of other efforts, either in consideration or already deployed to stem the tide of the lingering opioid crisis. If successful, this solution has the potential to enhance health, lengthen life, and reduce illness and disability for those suffering from OUD.

Opioids have been significantly over-prescribed and are associated with numerous deaths, resulting in the nation’s current opioid crisis. The FDA recently approved the ?2 adrenergic agonist lofexidine as a non-addictive, non-opioid treatment for opioid use disorder (OUD), but there is a continued, urgent need to develop additional pharmacological alternatives to address both pain and OUD. The psychoactive, natural product, Mitragyna speciosa (kratom), has triggered significant interest in this space because Mitragynine, its main alkaloid, can interact with both mu opioid and ?2 receptors, offering a totally new approach for treating OUD. This project involves the synthesis and research of a series of Mitragynine analogs to better understand the pharmacological mechanisms that underlie Mitragynine’s opioid and adrenergic activities. If successful, this project will result in templates for the design of novel opioid receptor ligands. This advance would greatly improve the knowledge of interactions of these structurally novel compounds with opioid receptors and facilitate the development of these ligands as treatments for OUD.

Deaths from opioid overdose continue to rise; from 2015 to 2016, there was a 28 percent increase in the number of fatal overdoses. Currently available pharmacotherapies include MOR agonists (e.g., buprenorphine) and antagonists (e.g., naloxone), all of which suffer from specific and clear limitations. To address some of the key limitations, Intra-Cellular Therapies Inc (ITI) is developing ITI-333, a novel compound with high-affinity activity at mu opiate (MOP), 5-HT2A, and D1 receptors, that lacks abuse liability and thus offers great promise for the treatment of opioid use disorders. This proposal is for a 2-year UG3 program, including a first-in-human, single ascending dose (SAD) study to assess the safety, tolerability, and pharmacokinetics of ITI-333 in healthy volunteers. This study will then be repeated in a single-center in-patient study with the goal of determining a maximally- tolerated dose (MTD) and completed with human abuse liability and functional pharmacology studies. Together, the researchers believe this clinical development plan will inform further development of ITI-333 and the selection of a cogent Phase 3 clinical path toward FDA approval as a medication for the treatment of OUD.

To address the need for novel therapeutics for opioid use disorder (OUD), this research group identified ghrelin as an endogenous regulator of the mesocorticostriatal circuit, which contributes to the enhanced motivational attributes of addictive drugs and drug-associated cues. Ghrelin binds to the growth hormone secretagogue receptor 1? (GHS1?R) to transduce several physiological and behavioral processes, including the reward-related effects of opioid agonists. Systemic administration of a GHS1?R antagonist/inverse agonist dose-dependently attenuated self-administration of the addictive opioid analgesic oxycodone as well as oxycodone-seeking. This project proposes to employ a suite of validated rodent OUD models to define the preclinical profile for PF5190457, a selective GHS1?R antagonist/inverse agonist. PF5190457’s abuse liability, ability to suppress withdrawal and relapse-like behaviors, drug metabolism and pharmacokinetics, and brain penetrability in rats will be assessed. Phase 1 clinical studies in non–treatment seeking OUD participants will follow to assess the safety and tolerability of PF5190457.

Methadone is useful in the treatment of opioid dependence; however, methadone misuse and methadone-related fatalities have increased. Ensysce has created two complementary, novel technologies that can be applied to methadone. Their Trypsin Activated Abuse Protection (TAAP™) prodrugs are “enzyme-activated” to release clinically effective opioid drugs only when taken orally and exposed to the correct physiologic conditions, such as exposure to trypsin in the small bowel. Their multi-pill abuse resistance (MPAR™) feature involves in situ bioregulation of opioid delivery from the TAAP™ systems, enabling control over oral multi-dose pharmacokinetic profiles. It is envisaged that an R-methadone-TAAP™ prodrug would demonstrate similar reduced addiction liability as with other opioid-TAAP products. The objective of this proposal is to develop an R-methadone-TAAP™/MPAR™ drug through Phase 1 clinical studies and to translate R-methadone-TAAP™/MPAR™ results into humans, to ultimately reduce the misuse and oral overdose potential of methadone.

Naltrexone (NTX) has been proven as an important, safe, and effective therapy in helping patients overcome opioid addition and in preventing overdose. Unfortunately, the therapeutic potential of NTX has been blunted by poor adherence. To combat this issue, a system must be developed to deliver NTX for longer durations than are currently available with a more patient-friendly format. The goal of this research is to optimize and scale up our laboratory PLGA-based microparticle formulations of NTX delivery (either 2 months or 7–10 days) and bridge it to a Phase 1 clinical trial. This innovation will result in a more patient-friendly format consisting of less painful injections and improved release kinetics. PLGA-based drug delivery systems have been used successfully in a number of small-molecule products and are the most widely utilized and studied biocompatible polymer systems in controlled release. Thus, the regulatory and development hurdles with the FDA will be lower than with other novel excipients or technologies. The significance of this research and product development is that the final outcome of this project will ultimately provide a new, readily viable, essential tool to help patients overcome opioid dependence.

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.

Deaths from opioid overdose continue to rise; from 2015 to 2016, there was a 28 percent increase in the number of fatal overdoses. Currently available pharmacotherapies include MOR agonists (e.g., buprenorphine) and antagonists (e.g., naloxone), all of which suffer from specific and clear limitations. To address the main deficits in these treatments, the researchers will develop and optimize medications with longer duration of action that prevent and reverse the effects of opioids in a manner that is not surmounted by increasing doses of agonist. Their pilot studies in monkeys show that the pseudo irreversible MOR selective antagonist methocinnamox (MCAM) decreases heroin but not cocaine self-administration, decreases choice for remifentanil in a food/drug choice procedure, and reverses—as well as protects against—respiratory depression by heroin, with a single injection being effective for a week or longer. Bringing a medication like this to marketable fruition could significantly improve the treatment of OUD and save lives by providing insurmountable extended protection after rescue from overdose, including from ultra-potent fentanyl analogs.

The adverse effects of morphine and other mu-opioid receptor (MOR) agonists are linked to the ?-arrestin pathway, while analgesia is tied to the G-protein pathway. Pathway specific or “biased” drug development can target G-protein specific agonists that avoid the negative consequences of ?-arrestin signaling activation and produce analgesia. Highly “biased” MOR agonists have promise as effective analgesics but devoid of opioid-induced adverse effects. Preclinical studies compared two compounds, MEB-1166 and MEB-1170, against Oliceridine and morphine. Both compounds displayed no respiratory depression, even at high doses, while morphine and Oliceridine significantly reduced respiratory function. In contrast to morphine, neither MEB-1166 nor MEB-1170 produced conditioned place preference, suggesting an absence of abuse liability. This study will characterize the pharmaceutical and pharmacological profiles and perform liability studies for these compounds.