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

Last updated: July 9, 2025
Sponsor: University of Texas Southwestern Medical Center
Overall Status: Active - Not Recruiting

Phase

2

Condition

Stimulant Use Disorder

Treatment

Extended-Release Naltrexone

Placebo (PLB) Injectable matched to XR-BUP

Extended Release Buprenorphine

Clinical Study ID

NCT05262270
STU-2021-0223
UG1DA020024
  • Ages 18-65
  • All Genders

Study Summary

This is an 8-week, double-blind, randomized placebo-controlled trial of the efficacy of a combination of extended-release naltrexone (XR-NTX) and extended-release buprenorphine (XR-BUP) compared to matched placebo injections (PBO-Inj) for the treatment of cocaine use disorder (CUD).

Eligibility Criteria

Inclusion

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:

  1. Be 18 to 65 years of age;

  2. Be interested in reducing or stopping cocaine use.

  3. Be willing to comply with all study procedures and medication instructions.

Exclusion

Exclusion Criteria:

  1. 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.

Study Design

Total Participants: 427
Treatment Group(s): 5
Primary Treatment: Extended-Release Naltrexone
Phase: 2
Study Start date:
April 18, 2023
Estimated Completion Date:
December 31, 2026

Study Description

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.

Connect with a study center

  • University of Alabama at Birmingham

    Birmingham, Alabama 35209
    United States

    Site Not Available

  • University of Arkansas for Medical Sciences

    Little Rock, Arkansas 72205
    United States

    Site Not Available

  • UCLA Vine Street Clinic

    Los Angeles, California 90038
    United States

    Site Not Available

  • Center on Substance Use and Health (CSUH)

    San Francisco, California 94102
    United States

    Site Not Available

  • Cove Behavioral Health

    Tampa, Florida 33605
    United States

    Site Not Available

  • University of Chicago

    Chicago, Illinois 60637
    United States

    Site Not Available

  • University of Illinois at Chicago

    Chicago, Illinois 60608
    United States

    Site Not Available

  • Mountain Manor Treatment Center

    Baltimore, Maryland 21229
    United States

    Site Not Available

  • Berman Center for Outcomes and Clinical Research at Hennepin Healthcare

    Minneapolis, Minnesota 55404
    United States

    Site Not Available

  • Addictions Institute of Mount Sinai

    New York, New York 10029
    United States

    Site Not Available

  • UTSW Medical Center, Center for Depression Research and Clinical Care

    Dallas, Texas 75247
    United States

    Site Not Available

  • University of Texas Health San Antonio

    San Antonio, Texas 78229
    United States

    Site Not Available

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