Treatment Seeking Participants With Opioid Use Disorders Assessing Tolerability of Depot Injections of Buprenorphine

After completing an up to 2-week screening period, subjects entered an open-label run-in
induction phase with SUBOXONE (buprenorphine/naloxone) sublingual film for 3 days followed by
a 4- to 11-day SUBOXONE sublingual film open-label run-in dose-adjustment period to achieve
buprenorphine dosages ranging from 8 to 24 mg according to the SUBOXONE sublingual film
prescribing information.

This is a 24-week non-residential study with participants being randomized after meeting
randomization criteria. On Day 1 and Day 29 (± 2 days) participants will receive subcutaneous
injections of 300 mg RBP-6000 or placebo. Thereafter, participants will receive 4 injections
(once every 28 days ± 2 days) of either 300 mg or 100 mg RBP-6000 doses or placebo.

Inclusion Criteria:

- Currently meets Diagnostic and Statistical Manual of Mental Disorders, 5th Edition
(DSM-5) criteria for moderate or severe opioid use disorder

- By medical history has met DSM-5 criteria for moderate or severe opioid use disorder
for the 3 months immediately prior to signing the informed consent form

- Is seeking medication-assisted treatment for opioid use disorder

- Is an appropriate candidate for opioid partial-agonist medication-assisted treatment
in the opinion of the investigator or medically responsible physician

- Body mass index (BMI) of ≥ 18.0 to ≤ 35.0 kg/m^2

Exclusion Criteria:

- Current diagnosis other than opioid use disorder requiring chronic opioid treatment

- Current substance use disorder as defined by DSM-5 criteria with regard to any
substances other than opioids, cocaine, cannabis, tobacco, or alcohol.

- Positive urine drug screen (UDS) result at screening for cocaine or cannabis AND meets
DSM-5 criteria for either moderate or severe cocaine or cannabis use disorder,
respectively

- Meets DSM-5 criteria for moderate or severe alcohol use disorder

- Received medication-assisted treatment for opioid use disorder (e.g., methadone,
buprenorphine) in the 90 days prior to providing written informed consent