Funded Projects

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).

Tens of thousands of people die each year from opioid overdose. Many of these people began taking opioids for pain. A critical treatment goal is to reduce the development of opioid dependence either by enhancing opioid analgesia so lower doses can be used or by blocking withdrawal symptoms. Current pharmacological treatments in these two categories, although effective, present serious limitations. The recent finding that reducing the signaling through mu-delta opioid heterodimers appears to enhance opioid antinociception and reduce dependence suggests that a blocker of mixed mu-delta receptors (MDOR antagonist) could be effective in reducing dependence by limiting opioid tolerance and preventing opioid withdrawal. This research group has developed a compound with that characteristic, called D24M, which preliminary studies have shown could reduce opioid dependence by enhancing opioid antinociception, reducing opioid tolerance, or directly inhibiting opioid withdrawal. They propose to extend this research by investigating whether it can reduce chronic pain in an animal model that mimics the clinical situation of pain patients who transition to dependence. If these studies are successful, they could lead to the development of an optimized drug ready for Investigational New Drug (IND) application and enable translational and clinical testing.

Chronic pain is a significant public health problem associated with tremendous personal and economic burden. First-line treatment consists of opioid medications, but despite only moderate efficacy and unpleasant side effects, rates of opioid prescriptions have quadrupled over the past 15 years, and this has contributed to high rates of misuse, overdose, and mortality. Clearly, alternative, or non-opioid strategies for treating pain are needed. In this context, “opioid-sparing” medications refer to compounds that can be combined with and enhance the analgesic effects of lower-dose opioids without increasing the rewarding properties of either drug. There is preclinical evidence suggesting that cannabidiol (CBD) may have the potential to function as “opioid-sparing” medications, but its ability to alter opioid-mediated analgesia in humans has yet to be determined. This proposal will fill this gap by conducting a double-blind, placebo-controlled, within-subject randomized crossover study of the effects of CBD and morphine co-administration on pain sensitivity and subjective reinforcement on 28 healthy males and females. This is the first known study to investigate the ability of CBD to alter morphine’s analgesic effects in humans. If successful, the model will have a lasting impact on our ability to develop and test medications that reduce our reliance on chronic use of opioid medications for pain relief.

Novel treatments for opioid use disorder are critically needed as the addiction and overdose crises continue. Neuromodulation is a promising supplemental treatment to standard care. The overarching project seeks to evaluate low-intensity focused ultrasound that targets the nucleus accumbens, a primary component of the brain’s reward neurocircuitry. This supplement will expand the number of participants in part of the study and will increase the project’s overall impact consistent with the original objectives and aims of the parent grant.

This study will conduct preclinical and clinical assessments of the NMDA modulator NYX-783 for treatment of opioid drug-seeking and relapse to opioid use disorder (OUD). NYX-783, a novel small molecule being developed by Aptinyx, has shown evidence of safety/tolerability in Phase 1 studies and is currently in Phase 2 trials for post-traumatic stress disorder. This project will test the safety, tolerability, and pharmacokinetics (PK) of NYX-718 in morphine-maintained patients in residential settings and then conduct a combined inpatient (safety/tolerability/PK) / outpatient (preliminary efficacy) study testing NYX-783’s effects on opioid use and relapse, stress/cue reactivity, craving, and quality of life in OUD subjects maintained on standard extended release naltrexone over a 10-week period. Successful completion of these studies will set the stage for larger scale Phase 2/3 studies of efficacy in OUD that will ultimately be required for FDA approval of NYX-783 for the treatment of drug-seeking and relapse in OUD.