Extended-Release Naltrexone and Monthly Extended-Release Buprenorphine for Cocaine Use Disorder (CURB-2)

The primary objective of this study is to assess the efficacy of XR-NTX plus XR-BUP as a combination pharmacotherapy for CUD. Approximately four hundred and twenty-six adults will be randomized into the study at 8-12 sites in the U.S. Eligibility will be determined during a maximum 21-day screening period. After screening/baseline is completed and eligibility is confirmed, participants will be randomized and begin the 1-week medication induction phase followed by the 8-week medication phase of the trial.

Participants will be randomized in a 1:1 ratio to either 1) XR-NTX + XR-BUP arm and receive injections of extended-release naltrexone (XR-NTX; as Vivitrol®) and extended-release buprenorphine (XR-BUP; as SublocadeTM), or to 2) PBO-Inj matching the timeline and delivery methods of injections for the XR-NTX + XR-BUP arm. XR-NTX or PBO-Inj injections will be provided on the day of randomization and in Weeks 3 and 6. XR-BUP or PBO-Inj injections will be provided on days 3-5 following randomization and in week 4. During the 1-week induction phase and the 8-week medication phase, participants will be asked to attend clinic twice weekly for collection of urine samples and to complete assessments as indicated on the schedule of assessments. Following the 8-week medication phase, participants will be asked to attend clinic weekly for the follow-up phase during Weeks 9-12.

Participants will be involved in the study for approximately 16 weeks, including a screening/baseline period of up to 3 weeks (i.e., 21 days), 1 week for randomization and medication induction, 8 weeks of medication, and 4 weeks of follow-up. The screening phase may differ by participant in the length of time needed to complete preliminary eligibility assessments. Randomization and medication induction visit may take approximately 2 hours. Twice-weekly visits during the medication phase will range from about 20 to 90 minutes in length depending on scheduled assessments. Medication administration visits may require an additional 2 hours. Visits in the follow-up phase will take place approximately 30-60 minutes to complete. An 8-week medication period was selected based on expected time for group differences to emerge and for pragmatic issues related to medication dosing.

Enrollment is expected to take place over a period of approximately 13 months, with an approximate total of 16 months of study visits.