Conditions: Opioid Use Disorder
Keywords: Opioid dependent Buprenorphine Suboxone Film Opioid blockade Hydromorphone challenge
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 39
Healthy volunteers: no

Brief summary:
This is a multiple-dose study in non-treatment seeking male and female subjects with moderate to severe opioid use disorder who meet criteria from the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) to evaluate the effectiveness of RBP-6000 to block the effects of exogenous opioids.

The primary objective of this study was to demonstrate that the "Drug Liking" visual analog scale (VAS) measured after challenge with 6 mg (Dose 1) and 18 mg (Dose 2) hydromorphone was noninferior to the "Drug Liking" visual analog scale (VAS) measured after challenge with placebo at Weeks 1-4 post first injection of subcutaneous buprenorphine 300 mg (RBP-6000).

Detailed description:
For the hydromorphone challenge testing, subjects were randomized and assigned to 1 of 6 sequences during each week of hydromorphone challenge sessions.

On Day -18, subjects who met initial eligibility criteria were admitted to the clinical facility for the baseline hydromorphone challenge. If the subject had acceptable hydromorphone responses to the hydromorphone challenge, they remained confined to the clinical facility for induction on SUBOXONE sublingual film. Once it was confirmed that a subject was experiencing opioid withdrawal, as evidenced by a Clinical Opiate Withdrawal Scale (COWS) score greater than 12, the subject was inducted on SUBOXONE sublingual film. Multiple doses were allowed while subjects were reaching a stable dose until Day -9 when subjects were stabilized on a dose of SUBOXONE 8 mg - 24 mg. SUBOXONE sublingual film was administered daily at approximately the same time of day (± 1 hour) once the dose was stabilised. There was a hydromorphone challenge conducted on days -3 to -1. The last day of SUBOXONE dosing was day -1.

On Day 1, participants who met all inclusion/exclusion criteria and dosing criteria stopped receiving SUBOXONE sublingual film and received Injection 1 of RBP-6000 containing 300 mg buprenorphine. Participants returned in the evening of Days 4, 11, 18, and 25 to begin inpatient stays of 3 consecutive days (starting with Days 4-7 \[and equivalent for subsequent weeks\]). During these inpatient visits, subjects underwent randomised hydromorphone challenges, PK sample collection, Reinforcing Effects Tasks, and safety assessments.

On Day 29, participants received the second injection of RBP-6000 containing 300 mg buprenorphine (Injection 2). Participants returned in the evening on Days 32, 39, 46, 53, 60, 67, 74, and 81 to begin inpatient states of 3 consecutive days (starting with days 32-35 \[and equivalent for subsequent weeks\]). During these inpatient visits, subjects underwent randomised hydromorphone challenges, pharmacokinetic (PK) samples collection, Reinforcing Effects Tasks, and safety assessments. A window of ± 1 day was allowed for all visits, except the Day 53-56 visit, which was required by the protocol to be completed on those days.

Arms:
arm 1: Participants were treated with RBP-6000 300-mg in a single subcutaneous injection on Days 1 and 29 following a prior 14 day stabilization period (day -14 to day -1) of buprenorphine and naloxone (SUBOXONE) . Challenges consist of participants receiving on three consecutive days intramuscular (IM) injections of hydromorphone 0 mg (placebo), 6 mg and 18 mg doses during weeks 1-12 in randomized sequential order.

Interventions: intervention 1: Buprenorphine intervention 2: buprenorphine and naloxone intervention 3: hydromorphone intervention 4: placebo
Intervention descriptions: intervention 1: A subcutaneous depot injection of buprenorphine 300 mg was delivered using the ATRIGEL® Delivery System on study days 1 and 29. As the depot degrades, buprenorphine is released into systemic circulation over an extended period of time. intervention 2: Buprenorphine and naloxone (SUBOXONE® sublingual film) is given to participants on days -14 to day -1 (the SUBOXONE sublingual film stabilization period) or as soon as they start to experience withdrawal symptoms. SUBOXONE sublingual film may be initially administered several times daily until a stable dose between 8 mg and 24 mg daily is established. intervention 3: Hydromorphone IM challenges are administered during the screening period (days -17 to -15), on days -3 to -1 during the buprenorphine and naloxone (SUBOXONE sublingual film) stabilization period, and weekly during the 12-week treatment period after administration of RBP-6000. Each challenge consists of 3 days during which participants are randomly administered 0 mg (placebo), 6 mg and 18 mg hydromorphone via intramuscular (IM) injection daily in varying blinded sequences.

Additionally, hydromorphone can also be earned during the afternoon Reinforcing effects tasks sessions up to the same randomized dose received in the hydromorphone challenge that morning (or money can be chosen). intervention 4: Placebo for hydromorphone administered via intramuscular injection during each challenge.

Protocol document: