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A Pilot Study of the Effects of BCG Immunization on CSF and Blood-based Biomarkers in Older Adults.

Effects of Bacillus Calmette-Guérin (BCG) Immunization on Cerebrospinal Fluid (CSF) and Blood-Based Biomarkers in Older Adults: A Pilot

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04507126
Enrollment
20
Registered
2020-08-11
Start date
2021-03-01
Completion date
2022-12-09
Last updated
2025-12-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy

Keywords

Cognition, Alzheimer's disease, Memory, BCG, Immunization

Brief summary

A pilot study of the effects of Bacillus Calmette-Guérin (BCG) immunization on cerebrospinal fluid and blood-based biomarkers in older adults.

Detailed description

This single-site, open-label clinical trial will investigate the immune and neurobiological effects of BCG vaccination in cognitively unimpaired older adults and older adults with memory and thinking problems by measuring target engagement, pharmacodynamic response, and effect on Alzheimer's disease (AD) pathology and immune response markers. This study will also gather data on study feasibility, tolerability, and safety.

Interventions

Sponsors

Massachusetts General Hospital
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
55 Years to 80 Years
Healthy volunteers
Yes

Inclusion criteria

Study subjects meeting all the following criteria will be allowed to enroll in the study: 1. Age 55-80 inclusive; 2. Montreal Cognitive Assessment (MoCA ) ≥18; 3. Normal cognition as defined by Montreal Cognitive Assessment (MoCA) ≥ 26 or Mild Cognitive Impairment (MCI) as defined by the National Institute of Health Alzheimer's Association (NIA-AA) Workgroup (2011) and MoCA score between 18 and 25 (inclusive); 4. Education level, English language skills, and literacy indicates subject will be able to complete all assessments; 5. Ability to provide informed consent; 6. Willing and able to complete all assessment and study procedures, including blood draws, lumbar punctures, and clinical assessments; 7. If on cholinesterase inhibitor and/or memantine, doses are stable for 3 months prior to baseline; 8. Negative test results for Human Immunodeficiency Virus (HIV) antibody and Tuberculosis (TB) (QuantiFERON) at screening; 9. No prior Bacillus Calmette-Guérin (BCG) exposure either through birth vaccinations (born in North American) or BCG bladder cancer treatment. 10. Documentation of current flu season vaccination dated at least 60 days prior to baseline visit.

Exclusion criteria

Study subjects meeting any of the following criteria will not be allowed to enroll in the study: 1. History of chronic infectious disease, such as HIV or untreated or active hepatitis; 2. History of tuberculosis, positive interferon-gamma release assay (IGRA, also known as the QuantiFERON-TB test), including a test with a high reactivity to mycobacteria of non-tuberculosis variety; 3. Prior BCG vaccination, positive T-spot tuberculosis test or a T-spot test showing significant Mycobacteria exposure; 4. A positive Severe acute respiratory syndrome coronavirus, Polymerase Chain Reaction (PCR) result within 3 months of screening, or known close contact with a confirmed Coronavirus 19 (COVID-19) positive person or symptoms highly suspicious for COVID-19 (per Center for Disease Control (CDC) guidelines) within 1 month of screening, including fever, cough, shortness of breath, chills, muscle pain, new loss of taste or smell, vomiting or diarrhea, and/or sore throat, based on clinician's judgment; 5. History of treatment with metformin within the past one year; 6. Previous participation (ever) in active immunization research for Alzheimer's Disease (AD) or passive immunotherapy or other disease-modifying treatments for AD within the past three months; 7. Current treatment with immunosuppressants (calcineurin inhibitors, corticosteroids, or biological or cytotoxic immunosuppressants, or disease or condition likely to require high dose steroid or immunosuppressive therapy); 8. Other conditions or treatments associated with increased risk of infections or treatment with immunosuppressive medications for any reason; 9. Current treatment with aspirin \> 160 mg/day or chronic, daily nonsteroidal anti-inflammatory drugs (NSAIDs); 10. Chronic use of antibiotics; 11. History of keloid formation; 12. Living with someone who is immunosuppressed and/or at high risk for infectious diseases (for example, HIV+ or taking immunosuppressive medications for any reason), or in a job (e.g. healthcare) in which the subject works with immunosuppressed populations; 13. Other/confounding neurological or psychiatric condition, unstable medical or psychiatric conditions, contraindications to BCG use and lab abnormalities or concurrent medication use posing risk for BCG or study procedures; 14. Laboratory abnormalities in B12, Folate, thyroid stimulating hormone (TSH), or other common laboratory parameters that may contribute to cognitive dysfunction; 15. Laboratory abnormalities in Complete Blood Count (CBC), electrolytes, Liver Function Tests (LFTs), Blood Urea Nitrogen (BUN), Creatinine (Cr), total serum immunoglobulins, erythrocyte sedimentation rate (ESR), C reactive protein (CRP), or urinalysis posing risk to treatment with BCG per clinician judgment; 16. Laboratory abnormalities in prothrombin time /international normalized ratio (PT-INR), which would pose a risk to performing the lumbar puncture procedure; 17. Discontinuation of cholinesterase inhibitor or memantine within one month (28 days) prior to baseline visit; 18. Females who are pregnant, lactating or of child-bearing potential; 19. If male with female partner(s) of childbearing potential, unwilling or unable to adhere to contraception requirements specified in the protocol. 20. Administration of live vaccine \<60 days prior to Baseline. 21. Increased intracranial pressure as determined on a fundoscopy/neurological examination performed within 30 days of Lumbar Puncture (LP); 22. COVID-19 vaccination \< 60 days prior to baseline or within 14 days of BCG immunizations.

Design outcomes

Primary

MeasureTime frameDescription
Median Fold Change of Cytokine Levels From Day 0 to Day 90Day 90 compared to Day 0Heat-killed BCG or Lipopolysaccharide (LPS) applied to peripheral blood mononuclear cells (PBMCs) from subjects at 0 and 90d after study start. Calculated as median fold change of cytokine levels in media at day 90 (pg/mL) compared to day 0 (pg/mL)
Number of Participants With Treatment-Related Adverse EventsAEs were collected from baseline through study completion, an average of 390 daysNumber of Participants With Treatment-Related Adverse Events to determine safety of BCG

Secondary

MeasureTime frameDescription
Median Difference in CSF Biomarkers of Alzheimer's Disease (AD) Pathology From Day 0 to Day 90Day 90 compared to Day 0Median difference of biomarkers measured in pg/mL (Amyloid-β42/40, phospho-tau (p181 tau), glial fibrillary astrocytic protein (GFAP) and neurofilament light protein (NFL) biomarkers) in CSF from baseline to 90 days.
Median Fold Change in CSF Biomarkers of Pharmacodynamic Response From Day 0 to Day 90Day 90 compared to Day 0Median Fold change in CSF biomarkers from baseline measured in pg/mL (Interleukin 6 (IL6), Tumor Necrosis Factor alpha (TNFa), interleukin 1 beta (IL1beta), Interferon gamma (IFNg))
Cognitive Measures (RBANS) Total Scored Index, 3 Months After BCG InjectionDay 90 compared to Day 0Mean change in Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) from baseline to 3 months after BCG injection. Total Scaled Index (TSI) . Higher scores mean better performance on the RBANS Total Scaled Index. TSI Minimum 40, TSI Maximum 160.
Median Fold Change in Circulating Cytokines From Day 0 to Day 90Time Frame: Day 90 compared to Day 0Median Fold change in circulating cytokines in plasma from baseline measured in pg/mL (IL6, TNFa, IL1beta, IFNg)

Countries

United States

Participant flow

Participants by arm

ArmCount
BCG Immunization
All participants will receive two Bacillus Calmette-Guérin (Japan BCG) vaccine injections spaced four week apart. Each injection will have 1.8-3.9 x 10\^6 colony forming units (CFU) reconstituted in 0.1 mL saline. Bacillus Calmette-Guerin (BCG): Vaccine
16
Total16

Withdrawals & dropouts

PeriodReasonFG000
Overall StudyProtocol Violation4
Overall StudyWithdrawal by Subject3

Baseline characteristics

CharacteristicBCG Immunization
Age, Customized
55-80 Years Old
16 Participants
Blood collection16 Participants
Cerebrospinal Fluid (CSF) collection16 Participants
Number of participants that participated in cognitive testing16 Participants
Race/Ethnicity, Customized
Non Hispanic
16 Participants
Race/Ethnicity, Customized
White - caucasian/european heritage
16 Participants
Region of Enrollment
United States
16 Participants
Sex: Female, Male
Female
10 Participants
Sex: Female, Male
Male
6 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
0 / 16
other
Total, other adverse events
7 / 16
serious
Total, serious adverse events
0 / 16

Outcome results

Primary

Median Fold Change of Cytokine Levels From Day 0 to Day 90

Heat-killed BCG or Lipopolysaccharide (LPS) applied to peripheral blood mononuclear cells (PBMCs) from subjects at 0 and 90d after study start. Calculated as median fold change of cytokine levels in media at day 90 (pg/mL) compared to day 0 (pg/mL)

Time frame: Day 90 compared to Day 0

ArmMeasureGroupValue (MEDIAN)
BCG ImmunizationMedian Fold Change of Cytokine Levels From Day 0 to Day 90Interferon-gamma cytokine3254 pg/mL
BCG ImmunizationMedian Fold Change of Cytokine Levels From Day 0 to Day 90Interleukin-1 beta cytokine1.997 pg/mL
BCG ImmunizationMedian Fold Change of Cytokine Levels From Day 0 to Day 90Interleukin 6 cytokine16.83 pg/mL
BCG ImmunizationMedian Fold Change of Cytokine Levels From Day 0 to Day 90Tumor necrosis factor alpha cytokine-33.89 pg/mL
Primary

Number of Participants With Treatment-Related Adverse Events

Number of Participants With Treatment-Related Adverse Events to determine safety of BCG

Time frame: AEs were collected from baseline through study completion, an average of 390 days

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
BCG ImmunizationNumber of Participants With Treatment-Related Adverse Events0 Participants
Secondary

Cognitive Measures (RBANS) Total Scored Index, 3 Months After BCG Injection

Mean change in Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) from baseline to 3 months after BCG injection. Total Scaled Index (TSI) . Higher scores mean better performance on the RBANS Total Scaled Index. TSI Minimum 40, TSI Maximum 160.

Time frame: Day 90 compared to Day 0

ArmMeasureGroupValue (MEAN)
BCG ImmunizationCognitive Measures (RBANS) Total Scored Index, 3 Months After BCG InjectionDay 098.1 units on TSI scale
BCG ImmunizationCognitive Measures (RBANS) Total Scored Index, 3 Months After BCG InjectionDay 90104.1 units on TSI scale
Secondary

Median Difference in CSF Biomarkers of Alzheimer's Disease (AD) Pathology From Day 0 to Day 90

Median difference of biomarkers measured in pg/mL (Amyloid-β42/40, phospho-tau (p181 tau), glial fibrillary astrocytic protein (GFAP) and neurofilament light protein (NFL) biomarkers) in CSF from baseline to 90 days.

Time frame: Day 90 compared to Day 0

ArmMeasureGroupValue (MEDIAN)
BCG ImmunizationMedian Difference in CSF Biomarkers of Alzheimer's Disease (AD) Pathology From Day 0 to Day 90AB42/40-0.0005220 pg/mL
BCG ImmunizationMedian Difference in CSF Biomarkers of Alzheimer's Disease (AD) Pathology From Day 0 to Day 90NFL-47.17 pg/mL
BCG ImmunizationMedian Difference in CSF Biomarkers of Alzheimer's Disease (AD) Pathology From Day 0 to Day 90GFAP789.7 pg/mL
BCG ImmunizationMedian Difference in CSF Biomarkers of Alzheimer's Disease (AD) Pathology From Day 0 to Day 90p181- Tau1.058 pg/mL
Secondary

Median Fold Change in Circulating Cytokines From Day 0 to Day 90

Median Fold change in circulating cytokines in plasma from baseline measured in pg/mL (IL6, TNFa, IL1beta, IFNg)

Time frame: Time Frame: Day 90 compared to Day 0

ArmMeasureGroupValue (MEDIAN)
BCG ImmunizationMedian Fold Change in Circulating Cytokines From Day 0 to Day 90IFNg259.8 pg/mL
BCG ImmunizationMedian Fold Change in Circulating Cytokines From Day 0 to Day 90IL1beta33.47 pg/mL
BCG ImmunizationMedian Fold Change in Circulating Cytokines From Day 0 to Day 90IL6332.9 pg/mL
BCG ImmunizationMedian Fold Change in Circulating Cytokines From Day 0 to Day 90TNFa24.80 pg/mL
Secondary

Median Fold Change in CSF Biomarkers of Pharmacodynamic Response From Day 0 to Day 90

Median Fold change in CSF biomarkers from baseline measured in pg/mL (Interleukin 6 (IL6), Tumor Necrosis Factor alpha (TNFa), interleukin 1 beta (IL1beta), Interferon gamma (IFNg))

Time frame: Day 90 compared to Day 0

ArmMeasureGroupValue (MEDIAN)
BCG ImmunizationMedian Fold Change in CSF Biomarkers of Pharmacodynamic Response From Day 0 to Day 90Interferon gamma (IFNg)-.01 pg/mL
BCG ImmunizationMedian Fold Change in CSF Biomarkers of Pharmacodynamic Response From Day 0 to Day 90Interleukin 6 (IL6)7.332 pg/mL
BCG ImmunizationMedian Fold Change in CSF Biomarkers of Pharmacodynamic Response From Day 0 to Day 90Tumor Necrosis Factor alpha (TNFa)-.8676 pg/mL
BCG ImmunizationMedian Fold Change in CSF Biomarkers of Pharmacodynamic Response From Day 0 to Day 90Interleukin 1 beta (IL1B)23.74 pg/mL

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026