NCT06829238 · University of Alabama at Birmingham
Assessment of Metformin for Restoration of Immune Homeostasis in HIV+ and HIV- Individuals With a History of Injection Drug Use
((MET-IH))
What this study is about
This randomly assigned clinical trial (RCT) evaluates whether metformin can reduce systemic inflammation and improve immune function in individuals with a history of injection drug use, with or without HIV. Participants will receive metformin or placebo and undergo immune system assessments, including vaccine response evaluations.
View original scientific description
This randomized clinical trial (RCT) evaluates whether metformin can reduce systemic inflammation and improve immune function in individuals with a history of injection drug use, with or without HIV. Participants will receive metformin or placebo and undergo immune system assessments, including vaccine response evaluations.
Interventions
DRUG
Metformin
Participants will receive Metformin ER (500mg increasing to 1000mg) or placebo for 16 weeks to assess immune restoration and inflammatory response.
DRUG
Placebo
Participants will receive placebo for 16 weeks and assess immune restoration and inflammatory response.
BIOLOGICAL
Jynneos
All participants will take a Jynneos (MPOX) vaccine.
BIOLOGICAL
Capvaxvie
All participants will take a Capvaxvie (PCV21, pneumococcal) vaccine.
Primary outcome measures
Change in Serum C-reactive Protein (CRP)
Time frame: Baseline to Week 16
Assessed by Enzyme Linked Immunosorbent Assay (ELISA) of blood samples collected at baseline and at 16 weeks. Reported in mg/dL.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Provision of signed and dated informed consent.
- Stated willingness to comply with all study procedures and availability for the study duration.
- Aged 18 to 64 years old.
- Weight of at least 110 lbs.
- Body Mass Index (BMI) of 18.5-40. Enrollment of individuals with BMI \>40, deemed in good health, may be considered with approval.
- Willingness to receive Jynneos (MPOX) and Capvaxvie vaccines.
- Ability to take oral medication and willingness to adhere to the metformin treatment regimen.
- History of injection opioid, amphetamine, and/or cocaine use within the past 10 years (self-report).
- Use of non-prescription opioid, amphetamine, and/or cocaine within the past 30 days (self-report).
- Clinically confirmed urine drug screen for opioid, amphetamine, and/or cocaine within the past 30 days.
- Serum CRP \> 3 mg/dL.
- Glucose level between 70-180 mg/dL (non-fasting).
- Hemoglobin A1c (HbA1c) of 5.0-6.4%.
- CD4 count \> 200 cells/ml.
- If HIV-positive, HIV viral load \< 200 copies/ml.
- If HIV-positive, on anti-retroviral therapy (ART) for \>12 months.
Exclusion criteria
- Inability to give informed consent.
- Refusal or inability to have blood drawn.
- Bleeding disorder diagnosed by a doctor (e.g., factor deficiency, coagulopathy, platelet disorder requiring precautions).
- Pregnant or nursing individuals.
- Diabetes mellitus.
- History of severe renal impairment or eGFR \<60 mL/min/1.73m².
- Creatinine clearance \<60 mL/min.
- History of liver disease.
- ALT/AST \> 3× the upper limit of normal.
- Total bilirubin \>1.4 mg/dL.
- Albumin \<3.5 g/dL.
- Prothrombin \>1.5× the upper limit of normal.
- AUDIT-C score ≥8.
- Hemoglobin \<9.0 g/L.
- Absolute neutrophil count \<1,000/mL.
- Platelet count \<100,000/mL.
- History of acute or chronic metabolic acidosis.
- Serum bicarbonate \<22 mEq/L.
- Anion gap \>10 mEq/L.
- Serum lactate \>2.2 mmol/L.
- Serum vitamin B12 \<250 pg/mL.
- History of chronic diarrhea.
- Current use of metformin or other diabetes medications.
- History of myocardial infarction, endocarditis, stroke, heart failure, chronic obstructive pulmonary disease, or sepsis.
- Use of medications such as furosemide, nifedipine, ranolazine, vandetanib, or cimetidine (current or within the past 30 days).
- Active hepatitis B infection.
- Hepatitis C infection within 6 months of study entry; individuals with prior hepatitis C must be at least 6 months post-treatment with direct-acting antivirals.
- Previous receipt of Jynneos or pneumococcal vaccine within the past two years (self-report).
- Severe allergic reaction to metformin, Jynneos, or Capvaxvie (self-report). Blood donations exceeding 450 mL in the 8 weeks prior to enrollment, accounting for study-related blood draws.
- Any medical, psychiatric, social condition, or responsibility that, in the investigator's judgment, could interfere with study procedures.
Where
- Birmingham, Alabama
Collaborators
National Institute on Drug Abuse (NIDA)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Apr 22, 2026 · Source of record for eligibility and locations