A Phase 1 interventional study of VK4-116 and Placebo in Opioid Dependence and Opioid Use Disorder (OUD), sponsored by National Institute on Drug Abuse (NIDA). Not yet recruiting at 1 site in United States. Open to participants aged 18 Years to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-09.
Sponsored by National Institute on Drug Abuse (NIDA) · Phase 1, Interventional, and Treatment
This first-in-human, randomized, double-blind, placebo-controlled, single ascending dose (SAD), phase I study is designed to assess the safety, tolerability and pharmacokinetics of VK4-116 in healthy volunteers in fasted and fed state.
Approximately 48 healthy volunteers will be enrolled and randomized to receive either VK4-116 or a placebo within one of five ascending dose cohorts. Each cohort will consist of eight participants, with a 6:2 ratio of active drug to placebo assignment. Dose escalation decisions will be made following a review of blinded safety, tolerability, and pharmacokinetic (PK) data from the preceding cohort.
The proposed dose levels under fasting conditions are 50 mg, 100 mg, 200 mg, 400 mg, and 500 mg. Additional cohort will receive a 200 mg dose in a fed state, approximately 30 minutes after a high-fat, high-calorie breakfast. Dose adjustments may be made based on the safety, tolerability, and PK data observed in earlier cohorts.
Participants will be admitted to the research clinic one day prior to receiving their assigned treatment. Following the administration of VK4-116 or placebo, participants will be continuously monitored for adverse events, and PK blood samples will be collected at predetermined intervals. Participants will remain in the clinic for 4 days, until the 72-hour PK blood sample has been collected. Participants in the food-effect cohort will stay in the clinic for 8 days (for fasted stat followed by fed state assessments). A follow-up visit will be scheduled three days after discharge from the clinic.
1,472 studies on the registry are indexed under Opioid-Related Disorders; 290 are open to participants now.
This study's planned enrollment of 48 is below the median of 63 across 1,166 interventional studies indexed under Opioid-Related Disorders.
Browse Opioid-Related Disorders studies →National Institute on Drug Abuse (NIDA) is the lead sponsor of 393 studies on the registry; 19 are open to participants now.
Of its 14 completed or terminated interventional studies of FDA-regulated products, 6 (43%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Be a healthy male or female volunteer between 18 and 60 years of age, inclusive, at the time of consent.
A female study participant must meet one of the following criteria:
If of - agrees to use one of the accepted regimens from at least 30 days prior to the first administration of the study medication, during the study, and for at least 30 days after the last dose of the study medication. An acceptable method of contraception includes one of the following:
i. abstinence from heterosexual intercourse, ii. hormonal contraceptives (e.g., injectable/implant/insertable hormonal birth control products, transdermal patch), iii. intrauterine device (with or without hormones). OR agrees to use a double barrier method (e.g., condom and spermicide) during the study and for at least 30 days after the last dose of the study medication.
A male study participant that engages in sexual activity must agree to use a double barrier method (e.g., condom and spermicide) and agree to not donate sperm during the study and for at least 90 days after the last dose of the study medication.
Exclusion Criteria:
Have a history of renal disease or current renal function test values as follows:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
oral administration in fasted state
Drug: VK4-116
oral administration in fasted state
Drug: VK4-116
oral administration in fasted state
Drug: VK4-116
oral administration in fasted state
Drug: VK4-116
oral administration in fasted state
Drug: VK4-116
oral administration in fed state
Drug: VK4-116
oral administration
Drug: Placebo
D3R antagonist
Each of the four dose groups of n=8 participants will be assigned to active drug or placebo in the ration 6:2.
Number of Treatment-Emergent Adverse Events in Healthy Adult Participants
The number of treatment-emergent adverse events will be measured using a combination of data collection methods, including tracking adverse events and assessing their onset or worsening relative to the initiation of treatment. The most recent version of the Medical Dictionary for Regulatory Activities (MedDRA) preferred terms will be used to classify adverse events, including their relationship to the treatment and maximum severity. Events will be identified either through subject self-report or clinically significant abnormal findings on: (i) Physical examination (ii) Vital signs assessments (heart rate (BPM), systolic blood pressure (mmHg), diastolic blood pressure (mmHg), respiration rate (RPM), and temperature (F)) (iii) ECG assessment (QTcF) as determined by the Investigator/consulting board-certified cardiologist (iv) Clinical Laboratory Assessments
Time frame: 7 days for fasted condition, 11 days for fed condition
Cmax
maximum observed plasma concentration (ng/mL)
Time frame: 72 hours
AUC
area under the concentration-time curve (mg\*h/L)
Time frame: 72 hours
Tmax
time of maximum observed plasma concentration (hours)
Time frame: 72 hours
half life (t½)
VK4-116 elimination half-life (hours)
Time frame: 72 hours
Plan to share: Undecided
No publications or documents are linked to this record.
Start is estimated for Aug 2026; primary completion for Apr 2027, 8 months later.
Of 53 non-industry phase 1 interventional studies under Opioid-Related Disorders, half reached primary completion within 26 months of starting (the median), counting those still running; a quarter within 16 and three quarters within 47. This study's planned 8 months is below that.
Counting every sponsor, half of 77 studies reached it within 19 months; a quarter within 9 and three quarters within 33.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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National Institute on Drug Abuse (NIDA) →