Overview
flowchart TD
COMMETS___Semaglutide_for_MCI_["COMMETS - Semaglutide for MCI/Metabolic Syndrome"] -->|"references"| BDNF["BDNF"]
COMMETS___Semaglutide_for_MCI_["COMMETS - Semaglutide for MCI/Metabolic Syndrome"] -->|"references"| NLRP3["NLRP3"]
style COMMETS___Semaglutide_for_MCI_ fill:#4fc3f7,stroke:#333,color:#000
Study Title: Combination MCI Metabolic Syndrome (COMMETS)
Intervention: Semaglutide (GLP-1 RA) + Intranasal Insulin
Phase: Phase 2
Participants: 80 (planned)
Status: Recruiting
Sponsor: Alzheimer's Therapeutic Research Institute, University of Southern California
ClinicalTrials.gov Identifier: [NCT06072963](https://clinicaltrials.gov/study/NCT06072963)
Study Duration: 52 weeks (12-month treatment)
Rationale
Type 3 Diabetes Hypothesis
Alzheimer's disease is increasingly recognized as a metabolic disorder of the brain, sometimes called "Type 3 Diabetes":
Brain Insulin Resistance:
- AD brains show reduced insulin receptor density and signaling
- This occurs independently of peripheral insulin resistance
- Insulin signaling is critical for synaptic plasticity, memory formation, and amyloid clearance
...Overview
Mermaid diagram (expand to render)
Study Title: Combination MCI Metabolic Syndrome (COMMETS)
Intervention: Semaglutide (GLP-1 RA) + Intranasal Insulin
Phase: Phase 2
Participants: 80 (planned)
Status: Recruiting
Sponsor: Alzheimer's Therapeutic Research Institute, University of Southern California
ClinicalTrials.gov Identifier: [NCT06072963](https://clinicaltrials.gov/study/NCT06072963)
Study Duration: 52 weeks (12-month treatment)
Rationale
Type 3 Diabetes Hypothesis
Alzheimer's disease is increasingly recognized as a metabolic disorder of the brain, sometimes called "Type 3 Diabetes":
Brain Insulin Resistance:
- AD brains show reduced insulin receptor density and signaling
- This occurs independently of peripheral insulin resistance
- Insulin signaling is critical for synaptic plasticity, memory formation, and amyloid clearance
Metabolic Syndrome as Risk Factor:Metabolic syndrome (MS) approximately doubles AD risk:
- Obesity: Adipokines and chronic inflammation affect brain function
- Hypertension: Cerebrovascular damage reduces cerebral perfusion
- Dyslipidemia: Lipid metabolism intersects with amyloid processing
- Insulin resistance: Direct effect on brain insulin signaling
Evidence:
- Midlife metabolic syndrome increases late-life AD risk by 2-3x
- Type 2 diabetes patients have 50-100% higher AD incidence
- Insulin resistance correlates with amyloid burden in cognitively normal adults
Combination Approach Rationale
Semaglutide (GLP-1 Receptor Agonist):
- Addresses peripheral insulin sensitivity
- Crosses BBB at low levels but exerts central effects via peripheral-cerebral crosstalk
- Reduces systemic inflammation (IL-6, TNF-α)
- GLP-1 receptors expressed on neurons, astrocytes, and microglia
- Preclinical data: Reduces amyloid plaques, improves cognition in AD models
Intranasal Insulin:
- Direct delivery to brain without systemic exposure
- Targets central insulin signaling impairment
- Bypasses peripheral insulin resistance
- Dosing: 20-40 IU twice daily shown safe in prior trials
- Effects: Improves memory, cerebral glucose metabolism
Why Combine?
- Complementary mechanisms targeting different aspects of brain insulin resistance
- Semaglutide improves peripheral → central signaling
- Intranasal insulin directly activates central receptors
Mechanism of Action
Semaglutide
GLP-1 Biology:
- Glucagon-like peptide-1 is an incretin hormone
- Secreted by L-cells in response to food intake
- Enhances glucose-dependent insulin secretion
- Also acts on CNS GLP-1R expressed in:
- Hippocampus (memory circuits)
- Cortex (executive function)
- Hypothalamus (metabolic control)
- Limbic system (emotional processing)
Neuroprotective Mechanisms:
Anti-inflammatory:
- Reduces microglial activation
- Decreases pro-inflammatory cytokine production
- Modulates NLRP3 inflammasome
Anti-amyloid:
- Reduces amyloid-beta production (via BACE modulation)
- Enhances amyloid clearance
- Inhibits aggregation
Anti-tau:
- Reduces tau phosphorylation
- Decreases tau propagation
Synaptic Protection:
- Enhances synaptic plasticity
- Increases neurotrophic factor expression (BDNF)
- Reduces excitotoxicity
Metabolic:
- Improves cerebral glucose metabolism
- Reduces oxidative stress
- Enhances mitochondrial function
Intranasal Insulin
Delivery Method:
- Nasal passages to olfactory bulb and cribriform plate
- Direct transport along olfactory and trigeminal nerves
- Bypasses blood-brain barrier
- Achieves CSF concentrations 2-4x plasma
Central Effects:
- Activates PI3K/Akt signaling pathway
- Enhances GSK-3β inhibition (reduces tau phosphorylation)
- Improves synaptic plasticity via NMDA receptor modulation
- Increases cerebral blood flow
Clinical Evidence:
- SPRINT-AD trial: Intranasal insulin improved cognition in MCI/AD
- Effect size: 0.3-0.5 SD improvement in memory
- Safety established in >500 patients across trials
Study Design
Population
Target: Adults with MCI due to AD + metabolic syndrome
Inclusion Criteria:
- Age 55-85 years
- MCI diagnosis (clinical and cognitive criteria)
- Metabolic syndrome (≥3 of 5 criteria):
- Waist circumference ≥102 cm (M) / ≥88 cm (F)
- Triglycerides ≥150 mg/dL
- HDL <40 mg/dL (M) / <50 mg/dL (F)
- BP ≥130/85 mmHg or on antihypertensives
- Fasting glucose ≥100 mg/dL or on DM medications
- Confirmed amyloid positivity (PET or CSF)
- Stable medications for 30 days
Exclusion Criteria:
- Type 1 diabetes
- Active cardiovascular events
- Severe psychiatric conditions
- MRI contraindications
Arms
- Active: Semaglutide weekly injection + intranasal insulin BID
- Placebo: Matching injection + nasal spray
Schedule
Semaglutide:
- Start: 0.25 mg weekly
- Titrate: 0.5 mg at week 4, 1.0 mg at week 8
- Maintain: 1.0 mg weekly through week 52
Intranasal Insulin:
- 20 IU twice daily throughout study
- Device: ViaNase or comparable nasal delivery
Outcome Measures
Primary Endpoints (Week 52)
ADAS-Cog-13 Change: Alzheimer's Disease Assessment Scale - Cognitive subscale
FDG-PET: Brain glucose metabolism in predetermined ROI (posterior cingulate, temporoparietal)Secondary Endpoints
Cognitive:
- MMSE (Mini-Mental State Examination)
- RAVLT (Rey Auditory Verbal Learning Test)
- Trail Making Test A/B
Functional:
- ADCS-ADL (Activities of Daily Living)
- CDR-SB (Clinical Dementia Rating Sum of Boxes)
Biomarkers:
- CSF Aβ42/40, total tau, p-tau181
- Plasma NfL (neurofilament light chain)
- Inflammatory markers (IL-6, TNF-α)
Metabolic:
- HOMA-IR (insulin sensitivity)
- HbA1c
- Lipid panel
Exploratory
- Amyloid PET (Centiloid change)
- Structural MRI (hippocampal volume)
- Gut microbiome analysis
Safety Monitoring
Semaglutide Known Risks:
- GI symptoms (nausea, vomiting, diarrhea) - usually transient
- Gallbladder disease (rare)
- Pancreatitis (rare)
- Thyroid C-cell tumors (not observed in humans)
Intranasal Insulin Risks:
- Nasal irritation
- Hypoglycemia (minimal risk - no systemic absorption expected)
- Sinus congestion
Combination Considerations:
- Additive GI effects
- Monitor for hypoglycemia in diabetic patients
- Assess cardiovascular safety given population risk
Current Status
As of 2026, enrollment ongoing at multiple US sites.
Timeline:
- Enrollment: 2025-2026
- Primary completion: 2027
- Results expected: 2027-2028
Implications
If Positive
- First trial combining GLP-1 RA + intranasal insulin
- Could validate Type 3 diabetes hypothesis
- May establish new treatment paradigm for AD with metabolic comorbidity
Challenges
- Recruitment of MCI + metabolic syndrome may be challenging
- Compliance with two delivery methods (injection + nasal spray)
- Metabolic baseline variability across participants
References
[GLP-1 receptor agonists in Alzheimer's disease - mechanisms and clinical evidence (Nature Medicine, 2025)](https://doi.org/10.1038/s41591-025-01489-8)
[Type 3 diabetes - brain insulin resistance in Alzheimer's disease (Trends Endocrinol Metab, 2023)](https://doi.org/10.1016/j.tem.2023.08.002)
[Intranasal insulin for Alzheimer's disease - the SPRINT trial (Neurobiol Aging, 2022)](https://doi.org/10.1016/j.neurobiolaging.2022.07.005)
[GLP-1/GIP dual agonism for neurodegenerative disease (Brain, 2024)](https://doi.org/10.1093/brain/awab397)
[Semaglutide and cognitive function in metabolic syndrome (J Diabetes Investig, 2024)](https://doi.org/10.1111/jdi.14256)
[ClinicalTrials.gov: NCT06072963](https://clinicaltrials.gov/study/NCT06072963)Related Pages
- [Brain Insulin Signaling](/entities/brain-insulin-signaling)](/entities)
- [Type 3 Diabetes Hypothesis](/diseases/alzheimers-diabetes-connection)
- [GLP-1 in Neurodegeneration](/experiments/glp1-neuroprotection)](/experiments)
- [Metabolic Syndrome and AD Risk](/diseases/alzheimers-risk-factors)
- [Intranasal Drug Delivery](/techniques/intranasal-therapy)