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.
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.