The O'Neil Long Acting Naltrexone Implant (OLANI) Pharmacokinetic (PK)/Safety Study in Healthy Volunteers
OLANI PK/Safety Study in Healthy Volunteers
  • Phase

    Phase 1
  • Study Type

  • Study Participants

This study will examine the pharmacokinetic profile and safety of the O'Neil Long Acting Naltrexone Implant (OLANI) overtime in healthy volunteers. All participants will be treated in an open label manner. No randomization will occur. It is hypothesized that the OLANI will provide sustained therapeutic doses of naltrexone (NTX) for periods up to 6 months via a single subcutaneous application of 2 OLANIs.
Naltrexone (NTX) is a nonspecific pure opioid antagonist with a high affinity for the µ-opioid receptor. It blocks the effects of opioids by competitive binding at opiate receptors. NTX is used primarily in the management of opiate and alcohol dependence. It is available in the United States (US) as 2 formulations; a once daily oral formulation (Revia) and a once monthly intramuscular injection (Vivitrol). While NTX is a potent antagonist and efficiently blocks the effects of exogenous opiates such as heroin, the success of NTX for the treatment of opiate dependence has been limited by poor patient compliance. Therefore, the development of a sustained release NTX formulation (in excess of 1 month) would be of great benefit for the treatment of opioid use disorder.
Study Started
Apr 11
Primary Completion
Mar 18
Study Completion
Mar 22
Results Posted
Aug 01
Last Update
Oct 13

Drug naltrexone implant

1.8 g implant containing 60% naltrexone

  • Other names: OLANI, O'Neil Long Acting Naltrexone Implant

OLANI (naltrexone implant) Experimental

2 OLANI containing 60% naltrexone (1.8 g total) administered one time subcutaneously


Inclusion Criteria:

Men or women between the ages of 18 and 55 years old (inclusive)
Without The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM 5) - Substance Related Disorders classification; in sustained remission is not exclusionary
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)

Exclusion Criteria:

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 12 months.
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 physician.
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 administration.
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 participant.
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 International Neuropsychiatric Interview (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 (C-SSRS), 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.


OLANI (Naltrexone Implant)

All Events

Event Type Organ System Event Term OLANI (Naltrexone Implant)

Percentage of Participants That Maintain MEC

Percentage of participants who maintain naltrexone (NTX) blood levels of ≥1.33 ng/mL for ≥180 days

OLANI (Naltrexone Implant)

Median Cmax of Naltrexone

Single-dose pharmacokinetic (PK) measurement of the plasma naltrexone concentration (Cmax) after dosing on Day 1

OLANI (Naltrexone Implant)

ng/mL (Median)
Full Range: 5.38 to 71.4

Tmax of Naltrexone

Single-dose PK measurement of the time to reach the maximum (Tmax) naltrexone concentration after dosing on Day 1

OLANI (Naltrexone Implant)

day (Median)
Full Range: 0.47 to 268.0

AUC of Naltrexone

Single-dose PK measurement of the area under the curve (AUC) for naltrexone after dosing on Day 1

OLANI (Naltrexone Implant)

day*ng/mL (Median)
Full Range: 991.1 to 2022.0

Median Cmax of 6β-naltrexol

Single-dose PK measurement of the peak plasma 6β-naltrexol concentration after dosing on Day 1

OLANI (Naltrexone Implant)

ng/mL (Median)
Full Range: 10.2 to 126.0

Median Tmax of 6β-naltrexol

Single-dose PK measurement of the time to reach the maximum 6β-naltrexol concentration after dosing on Day 1

OLANI (Naltrexone Implant)

day (Median)
Full Range: 1.0 to 176.3

Time>Minimum Effective Concentration

Time (T) naltrexone remains above the minimum effective concentration (MEC) of 1.33

OLANI (Naltrexone Implant)

hours (Median)
Full Range: 6.0 to 48.0

AUC of 6β-naltrexol

Single-dose PK measurement of the AUC for 6β-naltrexol concentration after dosing on Day 1

OLANI (Naltrexone Implant)

day*ng/mL (Median)
Full Range: 1484.0 to 4990.0

Incidence of Adverse Events (AEs)

Incidence and Severity of AEs

OLANI (Naltrexone Implant)

Back pain






Implant site inflammation


Implant site pain


Implant site pruritus




Participants with at least One Treatment-Emergent Adverse Event


Upper respiratory tract infection




Weight increased


Age, Continuous

years (Mean)
Standard Deviation: 10.77

Body Mass Index (kg/m^2)

kg/m^2 (Mean)
Standard Deviation: 3.63

Ethnicity (NIH/OMB)

Race (NIH/OMB)

Region of Enrollment

Sex: Female, Male

Overall Study

OLANI (Naltrexone Implant)