Funded Projects

There are currently no effective non-opioid-based pharmacotherapies for treatment of opioid use disorder (OUD). Glial cell line-derived neurotrophic factor (GDNF) is a beneficial protein normally present in low levels in the adult brain, and there is strong evidence that it has clinical potential as a therapy for OUD and relapse reduction. Researchers have developed a non-invasive approach that bypasses the blood-brain barrier to increase levels of GDNF using intranasal administration of gene nanoparticles that make GDNF protein within the brain. This project will test whether this intranasal GDNF gene therapy can suppress drug craving and reduce the tendency to start using a drug again after a period of abstinence in experimental models, thus providing a long-term therapeutic strategy for reducing opioid craving and preventing relapse.

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.

Kappa opioid receptors (KOR) are expressed in brain areas that control reward, motivation, and anxiety. Upon opioid drug withdrawal and abstinence, dysregulated KOR signaling can result in aversive physical and affective states that are a major driver of relapse. Preclinical data have demonstrated that antagonism of KOR can reduce the physical symptoms of opioid withdrawal. Currently, the alpha 2-adrenergic agonist lofexidine is the only approved therapy for the mitigation of the physical symptoms of opioid withdrawal but it is only modestly effective and can have significant unwanted side effects. Cerevel Therapeutics has identified a novel selective KOR antagonist, CVL-354, with unique properties and good preclinical safety margins. This project will assess this drug in early human safety/pharmacokinetics and occupancy studies. Future studies will then be able to assess efficacy of this drug in acute opioid withdrawal.