Funded Projects

Currently no medications are approved by the U.S. Food and Drug Administration for psychostimulant (cocaine and methamphetamine) use disorder. This project will develop a novel opioid molecule (PPL-138) that blocks cocaine and methamphetamine self-administration in animal models and that lacks rewarding properties that could lead to addiction. This research will conduct manufacturing and safety studies to prepare for Phase 1 clinical trials to determine safety in human patients.

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.

This project aims to develop a novel abuse deterrent formulation (ADF) that will be uniquely designed to prevent abuse of the prescription pill. The study will focus on the development of the ADF with design aspects specifically focused on abuse through insufflation, smoking, injection, and taking multiple pills. The study will also validate the design by putting the pill through a rigorous test following the procedures outlined by the FDA Abuse-Deterrent-Opioids-Evaluation and Labeling guidelines. The study could result in the development of a novel ADF that will be resistant to a wide range of tampering, resulting in a safer formulation and pill design.

This research project will investigate the cannabinoid receptor 2 protein (CB2R) as a novel therapeutic target for opioid-induced respiratory depression caused by fentanyl, oxycodone, and heroin. This study will shed light on how the endocannabinoid system in the brainstem works to control breathing under normal conditions and during opioid-induced respiratory depression. The research aims to determine whether activation of the CB2R with a brain-penetrant CB2R-binding molecule is safe and clinically useful for treating opioid overdose prevention and reversal. This research will pave the way for discovering new medications that activate CB2R to reduce opioid-related deaths.

There is a need for an opioid use disorder (OUD) treatment that can prevent relapse in detoxified subjects. Titan's proprietary subdermal implants can provide long-term, non-fluctuating therapeutic levels of drug continuously following a single office-based insertion procedure. The non-biodegradable solid matrix implant formulation virtually eliminates the risk of accidental drug dumping and associated serious toxicity, and its subdermal location assures patient compliance for the 6-month treatment duration. Nalmefene hydrochloride (nalmefene) is an opioid receptor antagonist approved for the management and reversal of opioid overdose. Prototype nalmefene implants inserted subdermally in rats delivered nalmefene continuously for months without any observable safety concerns. This proposed study will develop a 6-month implantable device that delivers nalmefene at a steady rate to prevent relapse to opioid dependence following opioid detoxification. This project will manufacture nalmefene implants, complete nonclinical safety and pharmacology studies, and conduct clinical studies in OUD subjects to support a New Drug Application.

The sodium channel NaV1.8 is a promising target for the development of effective, non-addictive pain medications. Recent evidence from clinical studies indicates that medications that target NaV1.8 are effective at managing postoperative, neuropathic, and inflammatory pain, but with side effects and prohibitively high cost. This project will test the safety and compatibility in the body of an NaV1.8-targeted molecule, toward developing an effective, non-addictive, once daily oral medication for the treatment of acute postsurgical pain and chronic neuropathic. 

Currently there are no effective treatments approved by the U.S. Food and Drug Administration for cocaine use disorder. This project will explore the use of a novel class of small molecules that selectively block the molecule phosphodiesterase 7 (PDE7). Past research suggests that the PDE7 class of compounds helps restore normal functions of the dopamine reward system altered by chronic exposure to cocaine. This research will use both preclinical and clinical research studies to develop and test a PDE7 blocker, toward development of the first oral treatment for cocaine use disorder. 

Opioid use disorder (OUD) and opioid overdose (OD) are major health issues. Breathing can be restored after OD by naloxone, but its short half-life can require multiple administrations to reverse OD, and OD symptoms may return after initial reversal if illicit opioids are still present after the effects of naloxone have worn off. Additionally, while the standard treatment of OUD with buprenorphine and methadone reduces relapse and mortality, access and adoption are limited by dosage forms, metabolic liabilities, and potential for misuse and diversion. This study seeks to develop chemically novel, potent mu-opioid receptor (MOR) antagonists and low- and mid-efficacy partial agonists. Current lead counts can outcompete opioid overdoses in preclinical models with a longer half-life, a key naloxone liability for treating OD. The potent, low-efficacy partial agonists add a low opioid tone, diminishing the aversive effects of pure antagonists. These, and the mid-efficacy partial agonists, are leads to maintenance therapeutics for OUD.

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.

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.

Opioids remain the gold standard for treating moderate to severe pain, but their use is limited by numerous adverse effects, including tolerance, dependence, abuse, and overdose. Adverse effects could be avoided by combining an opioid with another drug, such that smaller doses of the opioid (in combination with another drug) produce the desired therapeutic effect. Direct-acting serotonin type 2 (5-HT2) receptor agonists interact in a synergistic manner with the opioid morphine to produce antinociceptive effects, suggesting a 5-HT2 receptor agonist could be combined with small amounts of an opioid to treat pain, thereby lowering the risk associated with larger doses. Unfortunately, very little is known about interactions between 5-HT2 receptor agonists and other opioids. The proposed studies will evaluate the therapeutic potential of mixtures of opioids and 5-HT2 receptor agonists using highly translatable and well-established procedures to characterize the antinociceptive, respiratory-depressant (overdose), positive-reinforcing (leading to misuse), and discriminative-stimulus (subjective) effects of drug mixtures as well as the impact of chronic treatment on the development of tolerance to and physical dependence on opioids. If successful, these studies will provide proof-of-concept for this innovative approach to pain treatment and evaluate the utility of targeting 5-HT receptors for analgesic drug development.

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.

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).