Cariprazine for Comorbid Cocaine and Opioid Use Didorder
Status:
Not yet recruiting
Trial end date:
2024-04-01
Target enrollment:
Participant gender:
Summary
This is a phase IIa, randomized, placebo-controlled pilot study designed to examine whether
low-dose cariprazine (1.5mg/d) impacts cocaine use in medically-stable OUD patients with
co-occurring CocUD who have already been taking BUP-NX at a stable dose for at least one week
(up to 24mg buprenorphine/6mg naloxone daily). To be eligible for this relapse-prevention
study, patients will have a cocaine-negative urine at the time of study enrollment.
Approximately 48 subjects will be randomized to participate in this study. At randomization,
patients will be stratified on cocaine-use severity, e.g., < 8 days cocaine use in the prior
month (less severe) vs. > 8 days cocaine use in the prior month (more severe). A subset
(n=24) of participants who are fMRI-eligible will also participate in an fMRI session during
the trial, examining whether cariprazine impacts the brain response to relapse-relevant
probes of reward and inhibition. All fMRI-eligible patients will be offered the scanning
opportunity, until 24 scans are acquired.
Blinding: This pilot study will be designated as single-blind. Participants are blind to
their medication status. In our single-blind studies, we also ask our clinical /
patient-interacting staff to remain "blind" to the participants' medication status (similar
to 'double-blind' studies), but our non-treatment (e.g., engineering) staff have access to
participant group status for preliminary data examinations.
After enrollment, subjects will be randomized to receive 1.5mg/d cariprazine or placebo in a
2:1 ratio. At baseline, subjects will complete several assessments, behavioral tasks and
neurocognition probes monitored by fNIRS and will then begin taking cariprazine (or placebo)
each day for 8 weeks. The behavioral tasks and fNIRS session will be collected again 10-17
days after taking the first dose of study medication, when plasma levels of cariprazine are
likely approaching steady-state; fMRI probes will be collected at the steady-state timepoint
in the fMRI-eligible subgroup. Urines will be collected 2x/weekly throughout the trial;
weekly blood samples will be analyzed for buprenorphine/norbuprenorphine as an index of
BUP-NX compliance, and for metabolites of cariprazine, for cariprazine compliance.
Individuals will participate for approximately 11 weeks, inclusive of the screening period
and follow-up visit; maximal study medication exposure for each subject is up to 8 weeks.
The study has 4 distinct phases:
1. Screening (approx. 1-2 weeks)
2. Baseline (1-2 visits; includes baseline assessments, behavioral tasks/fNIRS session, and
randomization)
3. Outpatient treatment (8 wks; 2 visits/wk, includes daily cariprazine (or placebo), daily
BUP-NX (at the participants' usual community treatment site), and imaging (fMRI and
fNIRS)/behavioral tasks at steady-state.
4. Follow-up: A follow-up visit to assess medical and psychological status will occur
approximately 1 week after the last dose of study medication.