Purpose

To determine whether metformin (MET) can improve the immune response to the pneumococcal conjugate vaccine (PCV-13) in older adults.

Conditions

Eligibility

Eligible Ages
Between 63 Years and 90 Years
Eligible Genders
All
Accepts Healthy Volunteers
Yes

Inclusion Criteria

  1. Age 63 to 89 years of age
  2. No history of pneumococcal vaccinations
  3. Able to take oral medications
  4. Able to provide informed consent
  5. Not currently taking metformin

Exclusion Criteria

  1. Previous vaccination with any pneumococcal vaccine
  2. Metformin within the last 6 months
  3. Contraindication for PCV13
  4. History of severe adverse reaction associated with any vaccine component
  5. Residence in long-term care facility
  6. Diagnosis of diabetes (diagnosis of pre-diabetes okay)
  7. Chronic renal disease (or eGFR <50 mL/min) or renal failure (defined as receipt of renal dialysis or transplant) or nephrotic syndrome
  8. History of adverse reaction or contraindications associated with metformin
  9. Recent history or plan for radiocontrast
  10. Self-reported dementia or severe cognitive impairment
  11. Receipt of blood products within 6 months before enrollment
  12. History of heart disease (New York Heart Classification greater than class II; more than non-specific ST-T wave changes on the ECG)
  13. History of chronic obstructive pulmonary disease
  14. Poorly controlled blood pressure (systolic BP>160, diastolic BP>90 mmHg)
  15. History of an immunodeficiency
  16. Use of use of investigational products, antibiotics, probiotics, or systemic immunosuppressive therapy (systemic steroids) within 1 month of study start; patients who are taking these medications chronically, with no expected discontinuation during the study period would not be considered ineligible.

Study Design

Phase
Phase 1
Study Type
Interventional
Allocation
Randomized
Intervention Model
Parallel Assignment
Primary Purpose
Basic Science
Masking
Triple (Participant, Care Provider, Investigator)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Metformin
Dosage is increased over the first 3 weeks up to three 500 mg tablets a day at 3 weeks, then continued on 3 tablets daily for a further 9 weeks.
  • Drug: Metformin
    Total daily dose titrated up to 1500 mg po q day over the course of 3 weeks and continued for a total exposure of 12 weeks.
    Other names:
    • Glucophage
Placebo Comparator
Placebo
Placebo tablet dosage is increased over the first 3 weeks up to three tablets a day at 3 weeks, then continued on 3 tablets daily for a further 9 weeks.
  • Drug: Placebo
    Placebo tablets titrated up to 3 tablets over the course of 3 weeks and then continued as 3 daily for a total exposure of 12 weeks
    Other names:
    • Placebo oral tablet

Recruiting Locations

UT Health San Antonio
San Antonio, Texas 78229
Contact:
Grace Lee, PhD
210-450-8097
leeg3@uthscsa.edu

More Details

NCT ID
NCT03713801
Status
Recruiting
Sponsor
The University of Texas Health Science Center at San Antonio

Study Contact

Grace Lee, PhD
12104508097
leeg3@uthscsa.edu

Detailed Description

The objective of this study is to determine whether metformin (MET) can improve the immune response to the pneumococcal conjugate vaccine (PCV-13) in older adults, and if this effect is mediated by the gut microbiota.

The proposed research projects will provide the necessary pilot data for future, more definitive, studies that will evaluate the impact of immunomodulatory therapies, such as MET therapy, on the aging immune system. The specific aims are:

Aim 1. Compare PCV13 vaccine response in elderly adults (≥63 years of age) treated with MET vs. placebo. For this study, 50 elderly volunteers will be enrolled and randomly assigned to receive MET or placebo. The hypothesis that MET can improve vaccine responsiveness by measuring serotype-specific IgG concentrations before and 30 days after PCV13 administration will be tested.

Aim 2. Determine whether the frequencies of immunophenotypes differ between elderly adults treated with MET vs. placebo. The mechanisms of MET's effect on the immune system by comparing immunophenotypes of MET and placebo groups between baseline and prior to PCV13 and between baseline and 30 days after PCV13 administration will be explored.

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.