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.

Individuals must meet all of the inclusion criteria and no exclusion criteria in order to be eligible to participate in the study, including but not limited to:

Inclusion criteria

• Be 18 to 65 years of age;
• Be interested in reducing or stopping cocaine use.
• Be willing to comply with all study procedures and medication instructions.

Exclusion criteria

• Have any condition for which, in the opinion of the site investigator or designee, study participation would not be in their best interest or that could prevent, limit, or confound the protocol-specified assessments.