Funded Projects

There are no FDA-approved medications for stimulant use disorders, and therapies for opioid use disorders remain suboptimal in ways that are now a focus of national attention. Thus, there is a clear need to identify new targets and explore new approaches for addiction medication development. Several lines of evidence suggest that PTPRD (receptor type protein tyrosine phosphatase D) may be a promising target for development of pharmacotherapeutics to treat not only stimulant use disorders but opioid use disorders as well. This research will focus on improving existing PTPRD ligands, identifying their effects on the dopamine and opioid systems, and moving the best novel, patentable PTPRD ligands toward human studies. If successful, this project will generate novel, well-tolerated, and bioavailable PTPRD ligands that display in vitro potency, selectivity and stability, and in vivo modulation of both cocaine and opioid-mediated reward at doses that present no significant toxicity.

The current studies are designed to examine a novel approach to treating OUD, namely use of a vaccine (OXY-KLH) targeted against oxycodone, one of the most commonly misused prescription opioids, and a vaccine (M-KLH) targeted against heroin/morphine. The researchers will evaluate the safety, immunogenicity, and preliminary efficacy of OXY-KLH and M-KLH. Overall, the proposed studies will provide a great deal of information about the safety and potential efficacy of the vaccines in reducing the addiction liability of opioids, which will be administered in a controlled laboratory setting. If the outcomes of the proposed studies with OXY-KLH and M-KLH are favorable, development of the bivalent vaccine (OXY-KLH plus M-KLH) that will target oxycodone and heroin will proceed. The long-term goal of this research is to develop a multivalent vaccine directed against oxycodone, heroin, and other relevant opioids.

Several abuse-deterrent opioid products (primarily formulations) are currently marketed or in clinical development, but they fall short of being resistant to abuse. Rather than abuse-deterrent formulations, this project, in partnership with Ensyce Biosciences, has created two complementary, novel technologies that control the release of known opioids. One technology delivers prodrugs — drugs that are not active until they have been exposed to the right conditions within the body, at which point they are gradually converted into active drugs, making them difficult to tamper with and reducing the potential for misuse. Another technology makes it so that taking increasing numbers of pills inhibits the process of converting prodrug into active drug, reducing the potential for overdose. This project aims to refine the development of these two technologies and work to combine them, and to translate promising animal results into human use.

The expansion of opioid prescribing in recent years to better treat pain has markedly increased their usage and availability and fueled an epidemic of abuse. Up to 80 percent of addicts reported initiating their habit through prescriptions drugs. Decreasing opioid prescriptions would lower opioid exposure, with fewer people receiving the drugs and less drug available for diversion. Study investigators have identified a novel target in the brain, distinct from any of the traditional opioid receptors capable of mediating potent analgesia without the reward behavior and side effects seen with traditional opioids. They targeted this site with a series of arylepoxamides and have identified a clinical candidate (MP1000) and backup compound. MP1000 is a potent analgesic in a range of thermal, inflammatory, and neuropathic analgesic assays. It fails to show reward behavior and does not produce respiratory depression at doses 5-fold greater than its analgesic ED50. Chronic administration does not produce physical dependence or withdrawal when challenged with an antagonist. It shows no cross tolerance to morphine and can be co-administered to subjects already on opioids for pain to lower their opioid usage (i.e., opioid sparing), facilitating the eventual discontinuation of the opioid. If successful, this project could lead to the development of a viable alternative to current opioid-based analgesics with reduced side effects (such as reward and respiratory depression) compared to opioids.

Levo-alpha-acetylmethadol (LAAM) offers numerous behavioral and clinical advantages for select opioid use disorder (OUD) patients who do not respond to standard treatment. While LAAM was withdrawn from the market despite being approved for OUD treatment, this project seeks to develop novel, patentable, convenient dosage forms of LAAM, including novel LAAM oral dosage formulations and novel buccal film formulations of LAAM. Morphology, mechanical property, drug release kinetics, and stability of the oral dosage and buccal film formulations will be characterized to determine the instant release or steady release of LAAM, respectively. The two lead LAAM formulations with adequate release and stability profiles will be chosen through optimization studies both in vitro and in vivo. A human pharmacokinetic/pharmacodynamic study will then be carried out on the two selected formulations.

To tackle the national public health emergency posed by opioid misuse, addiction, and overdose deaths, the development of effective new medications and the FDA drug approval process must be accelerated. In response to this call, INSYS Development Company, Inc. (INSYS) has developed a cannabidiol (CBD) oral solution that shows promise as a novel medication for prevention of relapse that addresses one of the five opportunities specified in the HEAL Initiative to improve treatment options. The first phase of this project involves clinical trials of CBD on cue-induced cravings, modulation of withdrawal, alterations of negative affect states, relapse to opioid use, and treatment retention in patients with OUD receiving buprenorphine treatment in a residential drug treatment facility. The findings from this phase will inform further studies in an outpatient setting. If successful, this project could advance to the development of a new monotherapy for the treatment of OUD.

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.