Phase 2
N=60
Intermittent Oral Naltrexone Enhanced With an Ecological Momentary Intervention for Methamphetamine-using MSM
Methamphetamine Use Disorder
Bottom Line
View on ClinicalTrials.gov: NCT04791969 ↗Enrolled (actual)
60
Serious AEs
3.3%
Results posted
Oct 2025
Primary outcome: Primary: Number of People With Meth-positive Urine Tests at Weekly Visits — 20; 13; 23; 9 Participants
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 2
- Interventions
- Naltrexone Hydrochloride (Drug); Placebo (Drug); Ecological Momentary Intervention (Behavioral)
- Age
- Adult, Older Adult · 18+ yrs
- Sex
- Male
- Sponsor
- Glenn-Milo Santos
- Primary completion
- Mar 2024
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Number of People With Meth-positive Urine Tests at Weekly Visits |
20; 13; 23; 9; 21; 10 | — |
| SECONDARY Mean in Sexual Risk Behaviors at Week 12 |
1.23; 1.0 | — |
Summary
This is a double-blind, placebo-controlled phase 2b trial in which 54 MSM who use meth will be randomly assigned (2:1) to receive 12 weeks of as-needed intermittent oral naltrexone 50 mg enhanced with an EMA-informed EMI platform, or receive as-needed placebo with EMA-informed EMI. The 12-week treatment period is consistent with other pharmacotherapy trials for substance use disorders. The proposed sample size is also consistent with other phase 2b trials for substance use treatment. Upon enrollment, participants will complete daily EMA assessments and weekly visits for behavioral surveys and urine testing for meth metabolites, study drug dispensing and computer-based counseling for substance use. Safety laboratory assessments and vital signs will be completed monthly. Efficacy (Specific Aims 1-3) will be assessed upon trial completion as measured by proportion meth-positive urine samples; PrEP and ART adherence by drug levels and viral load testing; and sexual risk behavior data accounting for PrEP use and viral suppression.
Eligibility Criteria
Inclusion Criteria
- cisgender male (male gender and sex assigned at birth)
- age 18-70 years* (naltrexone's tolerability and safety has been demonstrated among older adults up to age 70)
- self-reported condomless anal sex with men or missing Pre-Exposure Prophylaxis or antiretroviral therapy doses due to meth use in the prior three months while under the influence of meth
- self-reported meth use at least weekly
- mild, moderate or severe meth use disorder
- positive meth sample via sweat patch or urine testing during screening
- interested in reducing meth use
- no current acute illness requiring prolonged medical care
- no chronic illness that is likely to progress clinically during trial
- able and willing to provide informed consent and adhere to visit schedule
- current CD4 count ≥ 200 cells/mm3; or CD4 count of 100-199 cells/mm3 and HIV viral load 3 times upper limit of normal)
- impaired renal function (creatinine clearance < 60 ml/min)
- currently participating in another intervention research study with potential overlap
- severe alcohol use disorder as determined by structured clinical interview for DSM-5 criteria
- any condition that, in the PI and/or study clinician's judgment interferes with safe participation or adherence to study procedures
Data sourced from ClinicalTrials.gov (NCT04791969). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.