Evaluating Tetrahydrocannabinol as an Adjunct to Opioid Agonist Therapy

Phase 2

Recruiting

• Conditions: Fentanyl; Opioid Use Disorder; Methadone; Cannabis
• Interventions: Drug: Placebo

• Registration Number: NCT05985850
• Lead Sponsor: BC Centre on Substance Use

Brief Summary

This pilot study will evaluate the feasibility and safety of using 1:1 tetrahydrocannabinol (THC):Cannabidiol (CBD) cannabis oil as an adjunct therapy to methadone-based Opioid Agonist Therapy (OAT) for individuals with opioid use disorder (OUD) in a community setting.

Detailed Description

This is a single-site, two-phase pilot clinical trial evaluating the safety and feasibility of administering a balanced 1:1 ratio of THC:CBD cannabis oil alongside methadone-based opioid agonist therapy (OAT) in a community setting.

Phase 1 is a 12-week, double-blind, randomized controlled study involving 24 eligible participants with opioid use disorder (OUD) who recently initiated or re-initiated methadone-based OAT. Participants will be randomly assigned to receive either balanced THC:CBD cannabis oil or placebo oil. All participants will receive OUD clinical care, including OAT management, independent of research visits.

After the 12-week blinded treatment period (Phase 1), eligible participants will be invited to Phase 2, a 12-week open-label treatment extension study with all participants receiving balanced THC:CBD cannabis oil. Follow-up research visits will occur every two weeks from the start of open-label treatment.

Study Timeline

• Study First Submitted: 2023-07-26
• Study First Submitted QC: 2023-08-03
• Study First Posted: 2023-08-14
• Study Start: 2024-05-23
• Status Verified: 2025-02
• Last Update Submitted: 2025-02-14
• Last Update Posted: 2025-02-17
• Primary Completion: 2026-03
• Study Completion: 2027-03

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 24

Inclusion Criteria

1. Individuals of at least 25 years of age or older;

2. Diagnosed with OUD as per DSM-5 criteria;

3. Initiated or re-initiated methadone-based OAT within the past 30 days prior to study entry;

4. Cannabis-use experienced, defined as having used any amount of cannabis in the six months prior to the screening visit;

5. Willing to only use study-provided cannabis as directed by study protocol, including abstention from non-study cannabis and cannabinoids;

6. Agree to keep all study medication stored in a secure location and not to share/distribute study medication to any other individual;

7. If assigned female sex at birth:

   1. Be of non-childbearing potential, defined as (i) postmenopausal (12 months of spontaneous amenorrhea and over 45 years of age); or (ii) documented surgical sterilization (i.e., tubal ligation, hysterectomy, or bilateral oophorectomy); or
   2. If of childbearing potential, be willing to use an acceptable method of contraception throughout the study and have a negative pregnancy test at screening;

8. Ability to understand and comply with study protocol procedures and to provide written informed consent.

Inclusion criteria for Phase 2

In addition to meeting all eligibility criteria outlined in Phase 1, participants will be eligible for Phase 2 provided they meet ALL the following criteria at Week 12:

1. Participants who have not experienced a study medication-related serious adverse event during Phase 1;
2. Participants who have not been lost to follow-up during Phase 1.

Exclusion Criteria

1. Any disabling, severe, or unstable medical or psychiatric condition that, in the opinion of the study physician, precludes safe participation in the study or the ability to provide fully informed consent, as assessed by medical and psychiatric history, physical examination, vital signs, and/or laboratory tests;
2. Any severe or unstable co-morbid substance use disorder (e.g., delirium tremens, acute alcohol intoxication) that, in the opinion of the study physician, precludes safe participation in the study;
3. Currently pregnant or breastfeeding, or planning to become pregnant;
4. Known or suspected allergy or hypersensitivity to cannabinoids;
5. History of respiratory disease, severe cardiovascular, cerebrovascular, renal or liver disease;
6. Current or historic cannabis use disorder;
7. Taking warfarin, clopidogrel, clobazam, theophylline, clozapine and olanzapine medications as they may interact with cannabinoids in a clinically significant manner if they cannot be switched to a different medication;
8. Any personal or family history (first degree relative) of primary psychotic disorders (i.e., schizophrenia, schizoaffective disorder) as per DSM-5 criteria;
9. Unable to abstain from driving any vehicle or operating machinery for at least 10 hours after taking the study medication. In cases where impairment persists beyond the initial 10-hour period, participants must continue to adhere to these restrictions until the impairment resolves;
10. Actively participating in other interventional clinical trial(s);
11. Incarcerated, pending legal action or other reasons that might prevent completion of the study.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	Formulated using the same medium chain triglyceride (MCT) oil as Aurora 1:1 Drops (Indica) Induction and dosing will be ad libitum and sublingually self-administered. Initial dose will be 5 mg (equivalent to 0.25 mL)/day and participants will be able to titrate in increments of 2.5mg (0.125 mL)/day up to a maximum of 40 mg (2 mL)/day, in consultation with a study physician.

Primary Outcome Measures

Name	Time	Method
Incidence of Treatment-Emergent Adverse Events [Safety and Tolerability]	28 weeks	The safety will be evaluated by monitoring and gathering information on physical exam, vital signs, pregnancy testing, adverse events (AE) and serious adverse events (SAE), from the screening visit up to the End of Treatment (EOT)/Early Termination visit. AEs and SAEs will be monitored and recorded throughout the study duration. The proportion of participants who experience AEs or SAEs will be assessed by study arm.
Risk of Treatment Contamination	24 weeks	The proportion of participants using non-study cannabis in the control arm, and proportion of days in Phase 1 where non-study cannabis was used. Self-report of non-study cannabis use will be collected using the Timeline Follow Back (TLFB).
Acceptability	24 weeks	Participant satisfaction with the assigned treatment will be assessed through administration of the Medical Safety Questionnaire (MSQ) every 4 weeks during treatment phase The MSQ is a participant-completed questionnaire that evaluates participant satisfaction with study treatment on a 7-point Likert scale.
Adequacy of Dose	24 weeks	Patient satisfaction with dose level assessed through the adequacy of dose questionnaire and regular consultations
Participants' adherence to treatment	24 weeks	The degree of compliance with the recommended treatment plan, including study drug dosage and administration. This measures how well participants are able to stick to the prescribed treatment regimen and whether or not they are able to complete the full course of treatment. This will be assessed through a self-reported measure, such as study drug diary or treatment logs.
Blinding effectiveness	24 weeks	The blinding success questionnaire will be used to evaluate the participants' awareness of their assigned treatment.

Secondary Outcome Measures

Name	Time	Method
The monthly enrolment rates	24 weeks
The proportion of eligible participants who are willing to be randomized, willing to initiate the intervention and willing to complete 12-week assessments by study arm	24 weeks
The number of potential participants referred to the study	24 weeks
The proportion of scheduled study visits completed by study arm	24 weeks
The screening failure rates	24 weeks

Trial Locations

Locations (1)

Rapid Access Addiction Clinic (RAAC), St. Paul's Hospital; 🇨🇦 Vancouver, British Columbia, Canada