Opioid Use Disorder:

Opioids are a class of drugs that includes both the illicit drug heroin and prescription pain relievers such as morphine, fentanyl and others. Addiction is a chronic and relapsing brain disease characterized by a person pathologically pursuing reward and/or relief by substance use and other behaviors.  In 2017 over 11 million people misused prescription opioids, and over 2 million people reported having Opioid Use Disorder (OUD).  Opioid overdose deaths in the U.S. exceeded 60,000 in 2017, and Fentanyl-related overdose deaths increased by 45%. Drug overdose is the leading cause of accidental death in the US, with OUD driving this epidemic. Opioid overdose deaths drove down the US life expectancy over the last 3 years.

Medication-Assisted Treatment

Medication-Assisted Treatment (MAT) is the use of FDA approved medications, in combination with counseling and behavioral therapies, to provide treatment of OUD.  MAT is one of the major pillars of the federal response to the opioid epidemic in the US.  A consensus report issued in March, 2019 by the National Academy of Sciences concludes the MAT works and saves lives but is underused.  Naltrexone is one of the 3 medications commonly used to treat OUD and is also indicated for alcohol use disorders. Naltrexone blocks the euphoric and sedative effects of opioids by binding and blocking opioid receptors; it is reported to reduce opioid cravings, and is not addictive. It is available as a once daily pill (Revia®), or as a once-monthly injectable (Vivitrol®).  Unfortunately, medication adherence within OUD patients is poor; 50% and 85% of patients discontinued use of naltrexone by 6 weeks, and 25 weeks respectively while other studies indicate less than 10% retention after 4 months without incentives.

Benefits of DLP-160 (Once-Yearly Naltrexone Formulation)

Delpor is developing DLP-160, a 1-Year Sustained Release Naltrexone Implant for the prevention of relapse to opioid dependence.  The benefits of the product include the following:

  • 1-Year Duration ensuring complete medication adherence during therapy and a reduced relapse rate. A longer acting option is needed for patients who respond to naltrexone but fall out of maintenance therapy programs.
  • Zero-Order Release PK without any sub-therapeutic troughs ensuring complete prophylaxis for 1 year.
  • Fully reversible system: The device may be easily removed within minutes and drug plasma levels fall to zero within a few hours after removal in case pain treatment is needed due to injury or surgery. If pain treatment is not sufficient, former opioid users may seek to self-medicate with illicit opioids. Lack of reversibility represents a serious overhanging safety issue for injectable and erodible naltrexone systems that are expected to act over longer periods.
  • Same level of efficacy with lower drug exposure: Zero-order release eliminates the need for a drug burst in the beginning, achieving the same efficacy with lower drug exposure.