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Buprenorphine Extended-Release Subcutaneous Injection (RBP-6000) in High-risk Users

A Randomised, Double-Blind Study Comparing 2 Maintenance Dosing Regimens of Buprenorphine Extended-Release Subcutaneous Injection (RBP-6000) in Treatment-Seeking Adult Participants With Opioid Use Disorder and High-risk Opioid Use

Status
Completed
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04995029
Enrollment
785
Registered
2021-08-06
Start date
2021-10-26
Completion date
2024-06-26
Last updated
2026-02-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Moderate to Severe Opioid-use Disorder

Brief summary

The primary objective of the induction phase of the study is to compare treatment retention of participants following rapid induction or standard of care (SoC) induction onto extended-release buprenorphine. The primary objective of the maintenance phase is to compare the efficacy of 100 mg and 300 mg maintenance doses of extended-release buprenorphine administered every 4 weeks.

Detailed description

This study consists of an open-label induction phase followed by a double-blind maintenance phase. Each phase is designed to test separate objectives and endpoints. In the induction phase participants who use opioids via an injection route and/or use high doses of opioids who are in withdrawal will be randomly assigned in a 2:1 ratio to extended-release buprenorphine rapid induction or SoC induction. The rapid induction arm is designed to initiate extended-release buprenorphine treatment following a single dose of transmucosal (TM) buprenorphine, while the SoC induction arm inducts the participant onto extended-release buprenorphine using a TM buprenorphine-containing product for a minimum of 7 days. All participants will receive the first injection of extended-release buprenorphine on Day 1 and the second injection on Day 8. Participants eligible to continue treatment in the maintenance phase will be randomized at Week 6 prior to Injection 3 in a 1:1 ratio to receive maintenance doses of either 300 mg or 100 mg extended-release buprenorphine every 4 weeks for a total of up to 8 maintenance injections.

Interventions

DRUGTransmucosal Buprenorphine

Transmucosal (TM) buprenorphine as selected by the Investigator per local prescribing guidelines, administered either under the tongue (sublingual) or between the gum and cheek (buccal)

Administered by subcutaneous injection

Sponsors

Indivior Inc.
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Masking description

The induction phase of the study will be open label. The maintenance phase of the study will be conducted in a double-blind manner.

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. Has signed the informed consent form (ICF) and is able and willing to comply with the requirements and restrictions listed therein. 2. Is 18 years of age or older at the time of signing the ICF. 3. Currently meets Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) criteria for moderate or severe opioid use disorder (OUD). 4. Has a history of OUD as defined by documented medical history of OUD for at least 90 days immediately prior to providing informed consent. 5. Meets at least 1 of these criteria for high-risk opioid use at the Screening visit: 1. using opioids via the injection route for an average of 5 or more days per week in the last 4 weeks. 2. using at least 500 mg IV heroin equivalent (e.g., 1250 mg intravenous (IV) morphine) or self-reported use of any dose of highly potent synthetic opioids (fentanyl and analogues excluding transdermal patches) for an average of 5 or more days per week in the last 4 weeks by any route. 6. Is seeking medication for the treatment of OUD. 7. Is an appropriate candidate for opioid partial-agonist medications for opioid use disorder (MOUD) in the opinion of the Investigator or medically qualified sub-Investigator. 8. Agrees not to use buprenorphine-containing products other than those administered as part of study treatment for the duration of the treatment period. 9. A female participant is eligible to participate if she is not pregnant, not lactating and, if of childbearing potential, agrees not to become pregnant while on the study and to use medically acceptable means of contraception while on the study).

Exclusion criteria

1. Has current diagnosis, other than OUD, requiring chronic opioid treatment. 2. Has concurrent primary substance use disorder, as defined by DSM-5 criteria, other than opioid, tobacco, cannabis or alcohol use disorders. 3. Meets DSM-5 criteria for severe alcohol use disorder. 4. Has had significant traumatic injury or major surgical procedure (as defined by the Investigator) within 30 days prior to the first dose of RBP-6000 or still recovering from prior such injury or surgery. 5. Has congenital long QT syndrome, history of prolonged QT in the 3 months prior to Screening, or history of medications or other factors that are at risk for Torsades de Pointes. 6. Has abdominal area unsuitable for subcutaneous injections (e.g., nodules, scarring, lesions, excessive pigment). 7. Has history of suicidal ideation within 30 days prior to informed consent or history of a suicide attempt in the 6 months prior to informed consent. 8. Has uncontrolled intercurrent illness including, but not limited to, a medical or psychiatric illness/social situation that would limit compliance with study requirements or compromise the ability of the participant to provide written informed consent. 9. Has any other active medical condition, organ disease or concurrent medication or treatment that may either compromise participant safety or interfere with study endpoints. 10. Has total bilirubin ≥ 1.5 × upper limit of normal (ULN) (with direct bilirubin \> 1.3 mg/dL), alanine aminotransferase (ALT) ≥ 3 × ULN, aspartate aminotransferase (AST) ≥ 3 × ULN, serum creatinine \> 2 × ULN, or international normalized ratio (INR) \> 1.5 × ULN at Screening. 11. Has known allergy or hypersensitivity to buprenorphine or any component of the ATRIGEL Delivery System. 12. Is undergoing concurrent or has had prior treatment with any long-acting form of buprenorphine-containing product in the past 2 years, or if \> 2 years has a positive UDS for buprenorphine at screening; treatment with oral buprenorphine, oral naltrexone or methadone products within 14 days prior to consent; or treatment with depot naltrexone within the 3 months prior to consent. 13. Is undergoing concurrent treatment with another investigational agent or enrollment in another clinical study (except for an observational study) or treatment with another investigational agent within 30 days prior to Screening. 14. Is undergoing concurrent treatment with medications contraindicated for use with buprenorphine as per local prescribing information. 15. Has any pending legal status or pending legal action that could prohibit full participation in or compliance with study procedures. 16. Is under court order requiring treatment for OUD. 17. Is a member of site staff and/or has a financial interest in Indivior, or is an immediate family member of either the site staff and/or Indivior employee, directly involved in the study.

Design outcomes

Primary

MeasureTime frameDescription
Maintenance Phase: Percentage of Responders for Weekly Opioid Use Over Weeks 20 to 38Weeks 20 to 38A responder for weekly opioid use is defined as a participant whose percentage of visits with opioid abstinence is greater than or equal to 80% over Weeks 20 to 38 inclusive. Opioid abstinence is defined as a negative urine drug screen (UDS) result and negative responses to the TimeLine Follow Back (TLFB) interview for opioid use. The TLFB asks participants to retrospectively estimate their daily drug use for each of the past 7 days prior to the visit.
Induction Phase: Percentage of Participants Receiving Injection 2 at the Week 2 VisitWeek 2Treatment retention at Injection 2 was defined as the proportion of participants receiving Injection 2 at the Week 2 Visit among those in the Evaluable Population for Treatment Retention/Discontinuation. Participants who received Injection 2 at Week 2 (nominal) Visit and those who missed Injection 2 at Week 2 (nominal) Visit but received Injection 3 at the Week 6 Day 36 Visit were counted as "Yes" for treatment retention at Injection 2; otherwise, participants were counted as "No".

Secondary

MeasureTime frameDescription
Maintenance Phase: Percentage of Days Opioids Were Used Over Weeks 10 to 38Weeks 10 to 38Participants' percentage of days opioids were used out of days assessed over Weeks 10 to 38 (inclusive), based on the TLFB for the prior week.
Maintenance Phase: Percentage of Responders for Weekly Opioid Use Over Weeks 10 to 38Weeks 10 to 38A responder for weekly opioid use is defined as a participant whose percentage of visits with opioid abstinence is greater than or equal to 80% over Weeks 10 to 38 inclusive. Opioid abstinence is defined as a negative urine drug screen (UDS) result and negative responses to the TimeLine Follow Back (TLFB) interview for opioid use. The TLFB asks participants to retrospectively estimate their daily drug use for each of the past 7 days prior to the visit. Opioid use will be assessed at 15 visits between Weeks 10 and 38.
Maintenance Phase: Percentage of Visits With Opioid Abstinence Over Weeks 10 to 38Weeks 10 to 38Opioid abstinence is defined as negative urine drug screen results and negative responses to the TimeLine Follow Back (TLFB) interview for opioids. The TLFB asks participants to retrospectively estimate their daily drug use for each of the past 7 days prior to the visit.
Maintenance Phase: Percentage of Responders for Weekly Opioid Use Over Weeks 30 to 38Week 30 to 38A responder for weekly opioid use is defined as a participant whose percentage of visits with opioid abstinence is greater than or equal to 80% for the last 5 visits planned for urine drug screen (UDS) and TimeLine Follow Back (TLFB) over Weeks 30 to 38 (inclusive). Opioid abstinence is defined as a negative UDS result and negative responses to the TLFB interview for opioid use. The TLFB asks participants to retrospectively estimate their daily drug use for each of the past 7 days prior to the visit.
Maintenance Phase: Percentage of Responders for Daily Opioid UseWeek 30 to 38A responder for daily opioid use is defined as a participant with 20% or less days of opioid use, based on the TimeLine Follow Backs (TLFBs) collected at the last 5 observed visits post randomization. The TLFB asks participants to retrospectively estimate their daily drug use for each of the past 7 days prior to the visit.
Maintenance Phase: Percentage of Visits With Opioid Abstinence OverallWeek 2 to 38Opioid abstinence is defined as negative urine drug screen results and negative responses to the TimeLine Follow Back (TLFB) interview for opioids at all assessments between Weeks 2 and 38. The TLFB asks participants to retrospectively estimate their daily drug use for each of the past 7 days prior to the visit.
Maintenance Phase: Percentage of Days Opioids Were Used OverallWeek 2 to 38For each participant, the percentage of days opioids were used out of days assessed over Weeks 2 to 38 (inclusive), based on the TimeLine Follow Back (TLFB) for the prior week of each visit.
Maintenance Phase: Percentage of Days Opioids Were Used Via the Injection RouteWeeks 10 to 38For participants who use opioids via the injection route for an average of 5 or more days per week in the last 4 weeks prior to Screening, the percentage of days opioids were used via the injection route out of days assessed based on the Timeline Follow Back (TLFB) interview for the prior week of each visit.
Maintenance Phase: Average Number of Times Opioids Were Used Per Week by VisitBaseline to Week 38The average number of times opioids were used per week for a given visit based on the TimeLine Follow Back (TLFB) for the prior week collected at that visit.
Maintenance Phase: Change From Baseline in Number of Times Opioids Were Used Per WeekBaseline to Week 38The change in participants' number of times opioids were used per week from randomization baseline to each visit based on the 7 daily TimeLine Follow Back (TLFB) for the prior week collected at that visit.
Maintenance Phase: Percentage of Participants Who Were Opioid Abstinent by VisitBaseline to Week 38Opioid abstinence is defined as negative urine drug screen results and negative responses to the TimeLine Follow Back (TLFB) interview for opioids.
Maintenance Phase: Average Number of Days Opioids Were Used Per Week by VisitBaseline to Week 38The average number of days opioids were used per week out of days assessed, based on the TimeLine Follow Back (TLFB) for the prior week of each visit.
Maintenance Phase: Time From DB Randomization to Last Observed Study Visit (Treatment Retention)Up to 288 days after randomization (accounting for out-of-window visits)Treatment retention is defined as the number of days that participants remained in the treatment from randomization in the Maintenance Phase of the study until the date of the last observed study visit. The treatment retention since DB randomization is estimated using Kaplan-Meier method. The event is prematurely discontinuing the study prior to Week 38/EOT Visit.
Maintenance Phase: Percentage of Participants Who Complete the Last Scheduled InjectionWeek 34The proportion of randomized participants who completed the last scheduled injection of RBP-6000 at Week 34 were summarized using observed data. Missing data were not applicable for this endpoint.
Induction Phase: Percentage of Participants Retained at 5 Weeks35 daysPercentage of participants retained at 5 weeks after the first dose of TM buprenorphine was estimated using the Kaplan-Meier product limit method.
Induction Phase: Number of Participants With Adverse Events up to Injection 2Up to approximately 2 weeksThese endpoints encompassed all induction attempts and therefore utilized the first dose of transmucosal buprenorphine (TM BUP) for derivations. A treatment-emergent adverse event (TEAE) was defined as an AE having an onset date/time after administration of the first TM BUP dose and before the date/time of Injection 3. TEAEs up to RBP-6000 Injection 2 were TEAEs with a start date/time on or after the first dose of TM BUP and before the date/time of Injection 2.
Induction Phase: Number of Participants With Adverse Events Between Injections 2 and 3Approximately 4 weeksThese endpoints encompassed all induction attempts and therefore utilized the first dose of transmucosal buprenorphine (TM BUP) for derivations. A treatment-emergent adverse event (TEAE) was defined as an AE having an onset date/time after administration of the first TM BUP dose and before the date/time of Injection 3. TEAEs between RBP-6000 Injections 2 and 3 were TEAEs with a start date/time on or after Injection 2 and before the date/time of Injection 3.

Countries

Canada, United States

Contacts

STUDY_DIRECTORGlobal Director Clinical Development

Indivior Inc.

Participant flow

Recruitment details

Study Period was 26 Oct 2021 to 26 Jun 2024.

Pre-assignment details

Induction Phase: Participants were required to be in withdrawal (COWS score ≥8) to receive transmucosal (TM) buprenorphine (BUP). To receive RBP-6000, the participant did not display any allergic/ hypersensitivity reaction to TM BUP, did not experience precipitated withdrawal symptoms from the most recent TM BUP administration that would prevent RBP-6000 injection, and was not sedated. For standard of care, the participant had been dose-adjusted onto TM BUP for ≥7 days.

Baseline characteristics

Characteristic
Age, Categorical
Induction Phase
<=18 years
1 Participants
Age, Categorical
Induction Phase
>=65 years
5 Participants
Age, Categorical
Induction Phase
Between 18 and 65 years
252 Participants
Age, Categorical
Maintenance Phase
<=18 years
0 Participants
Age, Categorical
Maintenance Phase
>=65 years
3 Participants
Age, Categorical
Maintenance Phase
Between 18 and 65 years
430 Participants
Age, Continuous
Induction Phase
40.9 years
STANDARD_DEVIATION 10.68
Age, Continuous
Maintenance Phase
41.6 years
STANDARD_DEVIATION 10.87
Body Mass Index (kg/m2)
Induction Phase
26.91 kg/m2
STANDARD_DEVIATION 6.085
Body Mass Index (kg/m2)
Maintenance Phase
26.75 kg/m2
STANDARD_DEVIATION 6.157
Detoxed From Opioids Previously (Yes)
Induction Phase
0 Participants
Detoxed From Opioids Previously (Yes)
Maintenance Phase
324 Participants
Ethnicity (NIH/OMB)
Induction Phase
Hispanic or Latino
0 Participants
Ethnicity (NIH/OMB)
Induction Phase
Not Hispanic or Latino
614 Participants
Ethnicity (NIH/OMB)
Induction Phase
Unknown or Not Reported
4 Participants
Ethnicity (NIH/OMB)
Maintenance Phase
Hispanic or Latino
0 Participants
Ethnicity (NIH/OMB)
Maintenance Phase
Not Hispanic or Latino
0 Participants
Ethnicity (NIH/OMB)
Maintenance Phase
Unknown or Not Reported
0 Participants
Fentanyl + Any Other Drug Class on Screening UDS142 Participants
Fentanyl UDS Result at Induction Day 1 Visit
Induction Phase
367 Participants
Fentanyl UDS Result at Induction Day 1 Visit
Maintenance Phase
0 Participants
Main Route of Opioid Use Last 4 Weeks
Induction Phase
Injection
79 Participants
Main Route of Opioid Use Last 4 Weeks
Induction Phase
Oral
9 Participants
Main Route of Opioid Use Last 4 Weeks
Induction Phase
Other
3 Participants
Main Route of Opioid Use Last 4 Weeks
Induction Phase
Smoking
327 Participants
Main Route of Opioid Use Last 4 Weeks
Induction Phase
Snorting
174 Participants
Main Route of Opioid Use Last 4 Weeks
Maintenance Phase
Injection
121 Participants
Main Route of Opioid Use Last 4 Weeks
Maintenance Phase
Oral
10 Participants
Main Route of Opioid Use Last 4 Weeks
Maintenance Phase
Other
1 Participants
Main Route of Opioid Use Last 4 Weeks
Maintenance Phase
Smoking
186 Participants
Main Route of Opioid Use Last 4 Weeks
Maintenance Phase
Snorting
117 Participants
Multiple Drug Class Use - Last 4 Weeks at Screening Self-report or UDS Prior to First DB Injection213 Participants
Opioids Lifetime Use (years)
Induction Phase
14.8 years
STANDARD_DEVIATION 9.77
Opioids Lifetime Use (years)
Maintenance Phase
14.8 years
STANDARD_DEVIATION 9.8
Opioid Use Last 4 Weeks (days)
Induction Phase
27.8 days
STANDARD_DEVIATION 1.17
Opioid Use Last 4 Weeks (days)
Maintenance Phase
27.8 days
STANDARD_DEVIATION 0.89
Previous Opioid Overdose (Yes)
Induction Phase
85 Participants
Previous Opioid Overdose (Yes)
Maintenance Phase
0 Participants
Race (NIH/OMB)
Induction Phase
American Indian or Alaska Native
0 Participants
Race (NIH/OMB)
Induction Phase
Asian
1 Participants
Race (NIH/OMB)
Induction Phase
Black or African American
0 Participants
Race (NIH/OMB)
Induction Phase
More than one race
0 Participants
Race (NIH/OMB)
Induction Phase
Native Hawaiian or Other Pacific Islander
1 Participants
Race (NIH/OMB)
Induction Phase
Unknown or Not Reported
30 Participants
Race (NIH/OMB)
Induction Phase
White
0 Participants
Race (NIH/OMB)
Maintenance Phase
American Indian or Alaska Native
6 Participants
Race (NIH/OMB)
Maintenance Phase
Asian
0 Participants
Race (NIH/OMB)
Maintenance Phase
Black or African American
0 Participants
Race (NIH/OMB)
Maintenance Phase
More than one race
0 Participants
Race (NIH/OMB)
Maintenance Phase
Native Hawaiian or Other Pacific Islander
0 Participants
Race (NIH/OMB)
Maintenance Phase
Unknown or Not Reported
12 Participants
Race (NIH/OMB)
Maintenance Phase
White
314 Participants
Sex: Female, Male
Induction Phase
Female
323 Participants
Sex: Female, Male
Induction Phase
Male
0 Participants
Sex: Female, Male
Maintenance Phase
Female
95 Participants
Sex: Female, Male
Maintenance Phase
Male
0 Participants
Used Fentanyl ≥14 Times/Week AND Daily in the Last 7 Days Prior to Screening90 Participants
Used Fentanyl ≥14 Times/Week in the Last 7 Days Prior to Screening88 Participants
Used Fentanyl Daily in the Last 7 Days at Screening111 Participants
Using Opioids Via Injection Route for Average of ≥5 Days Per Week in the Last 4 Weeks
Induction Phase
214 Participants
Using Opioids Via Injection Route for Average of ≥5 Days Per Week in the Last 4 Weeks
Maintenance Phase
0 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
EG003
affected / at risk
deaths
Total, all-cause mortality
1 / 4740 / 2550 / 2181 / 217
other
Total, other adverse events
135 / 47458 / 25511 / 21830 / 217
serious
Total, serious adverse events
7 / 4741 / 25511 / 21811 / 217

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 7, 2026