- Men or women between the ages of 18 and 55 years old (inclusive)
- Without DSM 5 (The Diagnostic and Statistical Manual of Mental Disorders, Fifth
Edition ) - Substance Related Disorders classification; in sustained remission is not
- Able and willing to comply with the requirements of the protocol
- Able and willing to provide written informed consent
- Willing to undergo a minor surgical procedure under local anesthetic to allow for
investigational drug administration in the subcutaneous tissue
- BMI inclusive of 18.5 to 30.0
- Have an initial weight between 45.3 and 81.6 kilograms (inclusive)
- Positive urine drug screen (UDS) at screening for illicit substances.
- Is currently on naltrexone medication.
- Has had a naltrexone implant in the past 24 months.
- Has received treatment with an extended naltrexone product (e.g. Vivitrol) in the past
- Has a condition which requires treatment with opioid based medication.
- Has a known hypersensitivity to naltrexone.
- Has a known hypersensitivity to poly-lactic based materials e.g. biodegradable
sutures, surgical implants or previous biodegradable implants.
- Has a known hypersensitivity to local anesthesia.
- Is prone to skin rashes, irritation or has a skin condition such as recurrent eczema
that is likely to impact the implant site area, or as determined by the evaluating
- Demonstrates any abnormal skin tissue in the proposed implantation area.
- Is pregnant or planning to be. Women need to have negative blood pregnancy test at
screening. Women need to agree to practice dual contraceptives.
- Participant is breastfeeding or planning to be.
- Has a current significant neurological (including cognitive and psychiatric
disorders), hepatic, renal, endocrine, cardiovascular, gastrointestinal, pulmonary,
hematological or metabolic disease unless currently controlled and stable with
protocol-allowed medication 30 days prior to proposed investigational product
- Any clinically important abnormal finding as determined by medical history, physical
examination, ECG or clinical laboratory tests.
- Any additional condition(s) that in the investigator's opinion would prohibit the
participant from completing the study or would not be in the best interest of the
- Alanine aminotransferase (ALT) or aspartate transaminase (AST) > 3 times the upper end
of the laboratory normal range.
- Any methadone use 14 days prior to screening, and up to Study Day 0.
- Current DSM-5 diagnosis of schizophrenia, bipolar, anxiety, or depressive disorder,
confirmed by the MINI diagnostic interview assessment, or currently treated with
medications for anxiety or depression. Past history (in remission DSM-5
classification) of anxiety or depression is not exclusionary.
- Any elevated risk for suicide measured using the Columbia Suicide Severity Rating
Scale, endorsing any of the items in the past month (C-SSRS, Lifetime)
- Is participating or intending to participate in any other clinical trial during the
duration of this study.