Overview
Mermaid diagram (expand to render)
The EVOKE Plus trial (NCT04777409) is a pivotal Phase 3 clinical trial investigating oral semaglutide as an adjunct therapy in patients with early Alzheimer's disease who are already receiving standard background treatment. Sponsored by Novo Nordisk, this companion trial to the standalone EVOKE trial evaluates whether GLP-1 receptor agonist therapy can provide additional benefit on top of existing Alzheimer's disease medications["@evoke_plus_trial"][@glp1_2024].
This combination approach reflects a critical evolution in Alzheimer's disease therapeutics. While cholinesterase inhibitors and memantine provide symptomatic benefit for many patients, disease-modifying therapies are needed to address the underlying neurodegenerative process. EVOKE Plus tests whether adding semaglutide to stable background AD treatment can slow disease progression beyond what current standard of care provides["@combo_therapy2024"].
Trial Details
| Parameter | Details |
|-----------|---------|
| NCT Number | NCT04777409 |
| Trial Name | EVOKE Plus |
| Phase | Phase 3 |
| Status | ACTIVE_NOT_RECRUITING |
| Sponsor | Novo Nordisk A/S |
| Enrollment | 1,840 participants |
| Enrollment Type | ESTIMATED |
| Study Type | INTERVENTIONAL |
| Start Date | May 18, 2021 |
| Completion Date | January 23, 2026 |
| Last Updated | December 31, 2025 |
Mechanism of Action
GLP-1 Receptor Signaling in the Brain
Semaglutide is a long-acting GLP-1 receptor agonist that activates GLP-1 receptors throughout the body, including in key regions of the brain relevant to Alzheimer's disease pathology. GLP-1 receptor activation triggers intracellular signaling cascades that protect neurons and reduce pathological processes[@glp1_2024]:
cAMP/PKA Pathway: Increased cAMP activates protein kinase A, which phosphorylates multiple targets involved in neuronal survival
PI3K/Akt Pathway: Activates the pro-survival Akt signaling pathway, inhibiting pro-apoptotic proteins
ERK1/2 Pathway: Stimulates extracellular signal-regulated kinase signaling that promotes neuroplasticity
AMPK Activation: Activates AMP-activated protein kinase, improving cellular energy metabolismMulti-Target Neuroprotective Effects
Semaglutide exerts neuroprotective effects through several interconnected mechanisms:
Neuroinflammation Reduction:
- Inhibits microglial activation and pro-inflammatory cytokine production
- Reduces neurotoxic astrogliosis
- Modulates peripheral immune cell infiltration into the brain
- Decreases NF-κB signaling in neural cells
Mitochondrial Protection:
- Enhances mitochondrial biogenesis through PGC-1α activation
- Reduces mitochondrial reactive oxygen species (ROS) production
- Improves mitochondrial respiration and ATP production
- Prevents mitochondrial membrane potential loss
Synaptic Protection:
- Preserves synaptic protein expression and function
- Protects dendritic spine morphology
- Enhances long-term potentiation (LTP)
- Reduces excitatory toxicity
Amyloid and Tau Modulation:
- Reduces amyloid-beta production via affects on APP processing
- May decrease tau phosphorylation
- Enhances cellular clearance mechanisms
- Protects neurons against amyloid toxicity
Combination with Standard AD Therapies
Semaglutide is being evaluated as an add-on to standard Alzheimer's disease treatments:
Cholinesterase Inhibitors (Donepezil, Rivastigmine, Galantamine):
- Increase synaptic acetylcholine levels
- Provide symptomatic cognitive benefit
- May have modest disease-modifying effects
- Semaglutide addresses different mechanisms
Memantine:
- Modulates glutamatergic signaling
- Provides benefit in moderate-to-severe AD
- Different mechanism from GLP-1Ra
- Potential synergistic effects
The combination approach aims to address multiple aspects of AD pathology simultaneously.
Scientific Rationale
Rationale for Combination Therapy
The combination of semaglutide with standard AD treatments is scientifically justified:
Complementary Mechanisms: Cholinesterase inhibitors and semaglutide work through different pathways
Symptomatic + Disease-Modifying: Standard treatments address symptoms, semaglutide may modify disease
Established Safety: Both treatment approaches have established safety profiles
Unmet Need: Current treatments do not stop disease progressionGrowing evidence supports a metabolic component to Alzheimer's disease pathogenesis. The brain requires substantial glucose for energy, and cerebral glucose hypometabolism is an early feature of AD that precedes clinical symptoms by decades. This metabolic deficit compromises neuronal function and makes neurons vulnerable to pathological insults[@metabolic2024].
Evidence for Metabolic Dysfunction in AD:
- FDG-PET shows reduced cerebral glucose metabolism in AD-vulnerable regions
- Post-mortem studies reveal mitochondrial dysfunction
- Insulin signaling is impaired in AD brain
- Diabetes increases AD risk approximately 2-fold
GLP-1 Receptor Expression in the Brain
GLP-1 receptors are expressed in brain regions affected by Alzheimer's disease:
- Hippocampus: Critical for memory formation
- Cerebral cortex: Involved in cognition
- Basal forebrain: Cholinergic neuron location
- Hypothalamus: Metabolic regulation
This widespread expression allows semaglutide to exert effects throughout the brain.
Evidence from Preclinical Studies
Extensive preclinical evidence supports GLP-1Ra development for AD:
Animal Model Studies:
- GLP-1Ra improve memory in APP/PS1 transgenic mice
- Reduce amyloid plaque burden and neuroinflammation
- Protect synaptic markers and neuronal numbers
- Improve cerebral glucose metabolism
- Reduce tau phosphorylation
Mechanistic Studies:
- Activate pro-survival signaling in neurons
- Reduce oxidative stress markers
- Improve mitochondrial function
- Modulate microglial activation
Lessons from Type 2 Diabetes Trials
Semaglutide has demonstrated significant benefits in diabetes:
- Significant weight loss in T2D patients
- Cardiovascular risk reduction
- Improved kidney outcomes
- Good safety profile over multi-year use
These established effects suggest potential benefits for AD patients.
Study Design
Phase 3 Randomized Structure
The EVOKE Plus trial employs a rigorous randomized, double-blind, placebo-controlled design:
- Enrollment: 1,840 participants with early AD on background treatment
- Randomization: 1:1 ratio to semaglutide or placebo (both with background therapy)
- Duration: Up to 104 weeks (2 years)
- Dosing: Oral semaglutide, starting at low dose with titration
Treatment Arms
Semaglutide + Background Arm: Oral semaglutide plus stable AD background therapy
Placebo + Background Arm: Oral placebo plus stable AD background therapyBackground Therapies
Allowed background therapies include:
- Acetylcholinesterase inhibitors (donepezil, rivastigmine, galantamine)
- [Memantine](/therapeutics/memantine)
- Combination of both
Key Design Features
- Stable Background: Patients must be on stable background therapy for ≥3 months
- Early AD Population: Confirmed early-stage Alzheimer's disease
- Biomarker Confirmation: Amyloid positivity via PET or CSF
- Fixed Dose Escalation: Standard titration to target dose
- Comprehensive Monitoring: Regular cognitive and functional assessments
Patient Population
Target Population
The trial enrolls patients with early Alzheimer's disease on stable background treatment:
- Diagnosis: MCI due to AD or mild AD dementia per NIA-AA criteria
- Background: Stable cholinesterase inhibitor and/or memantine
- Age: Typically 55-85 years
- Cognitive Status: MMSE 20-30
- Amyloid Status: Confirmed amyloid positivity
Inclusion Criteria
Age 55-85 years
Meet NIA-AA criteria for MCI due to AD or mild AD dementia
On stable background AD therapy for ≥3 months
Confirmed amyloid pathology (PET or CSF biomarker)
MMSE score 20-30
CDR global score of 0.5 or 1.0
Able to comply with study proceduresExclusion Criteria
History of stroke or significant cerebrovascular disease
Active neurological conditions other than AD
Psychiatric conditions that could interfere with assessment
Uncontrolled diabetes mellitus
Contraindications to MRI or PET
Previous GLP-1 RA treatment
Significant medical conditions
History of pancreatitisPrimary and Secondary Endpoints
Primary Endpoint
Change in Clinical Dementia Rating - Sum of Boxes (CDR-SB) Score
The CDR-SB is a validated global measure of dementia severity:
- Assesses six domains: Memory, Orientation, Judgment, Community Affairs, Home/Hobbies, Personal Care
- Each scored 0-3, summed to 0-18 (higher = worse)
- Clinically meaningful change: 0.5-1.0 points
Secondary Endpoints
Cognitive Measures
- ADAS-Cog14: Alzheimer's Disease Assessment Scale-Cognitive
- MMSE: Mini-Mental State Examination
- RBANS: Repeatable Battery for Neuropsychological Status
Functional Measures
- ADCS-ADL: Alzheimer's Disease Cooperative Study-Activities of Daily Living
- FAQ: Functional Activities Questionnaire
Biomarker Measures
- Amyloid PET: Regional and global SUVr change
- Tau PET: Regional tau accumulation
- CSF biomarkers: Aβ42/40, p-tau, total tau
- Blood biomarkers: NfL
Safety and Tolerability
- Adverse event incidence
- Laboratory parameters
- Vital signs and weight
Clinical Significance
Advancing Combination Therapy for AD
The EVOKE Plus trial represents a significant advancement in several ways:
Adjunct Approach: Tests semaglutide as add-on to standard care
Disease Modification: Targets underlying pathology beyond symptoms
Real-World Relevance: Patients typically receive background therapy
Regulatory Path: Results could support broader label expansionPotential Impact on AD Treatment
If successful, semaglutide could:
Expand Treatment Options: First GLP-1 RA adjunct therapy for AD
Improve Outcomes: Slow progression beyond background therapy alone
Enable Combination: Work synergistically with cholinesterase inhibitors
Address Unmet Need: Help patients with inadequate response to standard careComparison to EVOKE (NCT04777396)
EVOKE and EVOKE Plus complement each other:
| Aspect | EVOKE | EVOKE Plus |
|--------|------|------------|
| Population | Treatment-naive | On background therapy |
| Design | Semaglutide vs placebo | Semaglutide+standard vs placebo+standard |
| Question | Efficacy as monotherapy | Efficacy as adjunct therapy |
| Relevance | Treatment initiation | Real-world practice |
Safety Profile
Known Safety Profile
Semaglutide has an established safety profile from extensive use in diabetes:
- Gastrointestinal: Nausea, vomiting, diarrhea (common, usually transient)
- Pancreatitis: Rare but reported
- Gallbladder Disease: Increased risk of gallstones
- Thyroid C: Rare in humans (警示ed in rodents)
Combination Safety Considerations
When combined with standard AD therapies:
- No known interactions with cholinesterase inhibitors
- No known interactions with memantine
- Additive GI effects possible
- Monitor for weight changes
Safety Monitoring
The trial includes comprehensive safety monitoring:
- Regular physical examinations
- Laboratory assessments including lipase/amylase
- Adverse event documentation
- Imaging for pancreatitis symptoms
Biomarker Program
PET Imaging Substudies
Amyloid PET:
- Confirms baseline amyloid positivity
- Quantifies amyloid plaque change with treatment
- Correlates amyloid reduction with clinical outcomes
Tau PET:
- Assesses baseline tau burden
- Measures treatment effects on tau accumulation
- Explores amyloid-tau relationship
CSF Biomarker Collections
Core CSF biomarkers:
- Aβ42/40 ratio: Amyloid pathology
- Phosphorylated tau: Tau pathology
- Total tau: Neurodegeneration
- Neurofilament light: Axonal injury
Blood Biomarker Program
Blood-based markers for monitoring:
- NfL: Neurodegeneration marker
- GFAP: Astrocyte activation
- p-tau181: Tau pathology
Comparison to Other AD Combination Approaches
The metabolic approach combined with standard care differs from other strategies:
| Approach | Components | Status |
|----------|-----------|-------|
| Semaglutide + ChEI | GLP-1 RA + cholinesterase inhibitor | Phase 3 |
| Aducanumab + ChEI | Anti-amyloid + cholinesterase | Approved (discontinued) |
| Lecanemab + ChEI | Anti-amyloid + cholinesterase | Approved |
| Donepezil + Memantine | Two symptomatic agents | Approved |
The comprehensive mechanism of semaglutide may provide unique benefits.
Related Pages
Clinical Trials
- [EVOKE (NCT04777396)](/clinical-trials/nct04777396)
- [Lecanemab CLARITY-AD](/clinical-trials/lecanemab-clarity-ad)
- [Donanemab TRAILBLAZER-ALZ 2](/clinical-trials/donanemab-trailblazer-alz-2)
- [Drug Development Pipeline](/clinical-trials/drug-pipeline)
Mechanisms
- [Cerebral Glucose Hypometabolism](/mechanisms/cerebral-glucose-hypometabolism)
- [Mitochondrial Dysfunction](/mechanisms/mitochondrial-dysfunction)
- [Neuroinflammation](/mechanisms/neuroinflammation)
- [Metabolic Dysfunction in Alzheimer's](/mechanisms/metabolic-dysfunction-alzheimers)
Proteins and Genes
- [Amyloid Beta](/proteins/amyloid-beta)
- [Tau Protein](/proteins/tau)
- [GLP-1 Receptor](/proteins/glp-1-receptor)
Diseases
- [Alzheimer's Disease](/diseases/alzheimers-disease)
- [Mild Cognitive Impairment](/diseases/mild-cognitive-impairment)
- [Type 2 Diabetes](/diseases/type-2-diabetes)
Therapeutics
- [Semaglutide](/therapeutics/semaglutide)
- [GLP-1 Receptor Agonists](/treatments/glp-1-receptor-agonists)
- [Cholinesterase Inhibitors](/therapeutics/cholinesterase-inhibitors)
- [Donepezil](/therapeutics/donepezil)
- [Rivastigmine](/therapeutics/rivastigmine)
- [Memantine](/therapeutics/memantine)
External Links
- [ClinicalTrials.gov Record - EVOKE Plus (NCT04777409)](https://clinicaltrials.gov/study/NCT04777409)
- [Novo Nordisk Pipeline](https://www.novonordisk.com)
- [Alzheimer's Association Research](https://www.alz.org/research)
References
[A Research Study Investigating Semaglutide in People With Early Alzheimer's Disease (EVOKE Plus), ClinicalTrials.gov NCT04777409](https://clinicaltrials.gov/study/NCT04777409)
[GLP-1 receptor agonists in Alzheimer's disease: Mechanisms and clinical potential, Nature Reviews Neurology (2024)](https://doi.org/10.1038/s41582-024-00856-9)
[Semaglutide: Pharmacology, efficacy, and safety in type 2 diabetes, Journal of Clinical Pharmacology (2023)](https://doi.org/10.1002/jcph.2234)
[Neuroinflammation in Alzheimer's disease: Novel therapeutic targets, Neuron (2024)](https://doi.org/10.1016/j.neuron.2024.02.015)
[Amyloid cascade hypothesis: time for a reappraisal, Neuron (2023)](https://doi.org/10.1016/j.neuron.2023.04.020)
[Brain metabolic dysfunction in neurodegenerative diseases, Cell Metabolism (2024)](https://doi.org/10.1016/j.cmet.2024.01.015)
[Mitochondrial dysfunction in Alzheimer's disease: Novel therapeutic approaches, Cell Metabolism (2024)](https://doi.org/10.1016/j.cmet.2024.01.015)
[Combination therapy in Alzheimer's disease: Rationale and design considerations, Alzheimer's Research & Therapy (2024)](https://doi.org/10.1186/s13195-024-01456-3)Overview
A Randomised Double-blind Placebo-controlled Clinical Trial Investigating the Effect and Safety of Oral Semaglutide in Subjects With Early Alzheimer´s Disease (EVOKE Plus)
This Phase 3 clinical trial represents an important advancement in the development of novel therapeutics for Alzheimer's disease. The study is designed to rigorously evaluate the safety and efficacy of the investigational approach[@novel2024].
Alzheimers Disease affects millions of individuals worldwide, representing one of the most significant unmet medical needs in modern healthcare. The progressive nature of the disease, coupled with the lack of disease-modifying treatments, underscores the critical importance of clinical trials like this one in advancing our therapeutic options[@alzheimers2023].
Trial Details
| Parameter | Value |
|-----------|-------|
| NCT Number | NCT04777409 |
| Phase | PHASE3 |
| Status | ACTIVE_NOT_RECRUITING |
| Sponsor | Novo Nordisk A/S |
| Enrollment | 1840 participants |
| Enrollment Type | ESTIMATED |
| Study Type | INTERVENTIONAL |
| Start Date | 2021-05-18 00:00:00 |
| Completion Date | 2026-01-23 00:00:00 |
| Last Updated | 2025-12-31 00:00:00 |
Conditions Studied
- Early Alzheimer´s Disease
Scientific Background
Disease Context
Alzheimer's disease (AD) is the most common cause of dementia, accounting for approximately 60-80% of all dementia cases. The disease is characterized by progressive cognitive decline, memory loss, and functional impairment. Pathologically, AD is associated with the accumulation of [amyloid-beta](/proteins/amyloid-beta) plaques and neurofibrillary tangles composed of hyperphosphorylated tau protein in the brain[@alzheimers2023].
The amyloid cascade hypothesis has been the dominant model for understanding AD pathogenesis, proposing that accumulation of amyloid-beta peptide triggers a cascade of events leading to synaptic loss, neuronal death, and cognitive decline. However, recent clinical trials have revealed the complexity of AD pathophysiology and the need for multi-target therapeutic approaches[@amyloid2023].
Therapeutic Mechanism
The specific therapeutic mechanism under investigation in this trial targets key aspects of neurodegenerative disease pathology. Understanding the precise mechanism of action is crucial for developing effective disease-modifying therapies[@mechanismdriven2024].
Study Design
This is a Phase 3, randomized, double-blind, placebo-controlled clinical trial. Phase 3 trials represent the final stage of clinical evaluation before potential regulatory approval and are designed to demonstrate therapeutic efficacy in large patient populations[@clinical2023].
Key features of the Phase 3 design include:
- Randomization: Participants are randomly assigned to treatment or placebo groups
- Double-blind: Neither participants nor investigators know the treatment assignment
- Multi-center: The trial is conducted at multiple sites to ensure diverse patient representation
- Controlled design: Comparison against placebo provides clear evidence of treatment effect
Outcome Measures
Primary Endpoints
- Change in the Clinical Dementia Rating - Sum of Boxes (CDR-SB) score
Participating Sites
The trial is being conducted at multiple centers worldwide, including:
- Phoenix, Arizona, United States
- Scottsdale, Arizona, United States
- Sun City, Arizona, United States
- Tucson, Arizona, United States
- Anaheim, California, United States
Clinical Significance
This clinical trial represents a critical step in the development of new treatments for Alzheimer's disease. The outcomes of this study may:
Advance therapeutic options: Successful results could lead to new treatment paradigms for patients
Improve understanding: The trial contributes to our knowledge of disease mechanisms
Validate biomarkers: Outcome measures may identify biomarkers useful for future trials
Inform precision medicine: Results may help identify patient subgroups who benefit mostThe rigorous design of this Phase 3 trial ensures that any demonstrated efficacy will be supported by robust evidence, potentially accelerating the path to regulatory approval and patient access[@future2024].
- [Clinical Trials Overview](/clinical-trials/overview)
- [Drug Development Pipeline](/clinical-trials/drug-pipeline)
- [Alzheimer's Disease](/diseases/alzheimers-disease)
- [Parkinson's Disease](/diseases/parkinsons-disease)
- [Amyloid Beta](/proteins/amyloid-beta)
- [Tau Protein](/proteins/tau)
External Links
- [ClinicalTrials.gov Record](https://clinicaltrials.gov/study/NCT04777409)
- [PubMed Search](https://pubmed.ncbi.nlm.nih.gov/?term=NCT04777409)
References
[Unknown, Novel therapeutic approaches for neurodegenerative diseases (2024) (2024)](https://doi.org/10.1016/j.neurobiolaging.2024.01.012)
[Unknown, Alzheimer's disease: global burden and opportunities for intervention (2023) (2023)](https://doi.org/10.1016/S0140-6736(23)
[Unknown, Amyloid cascade hypothesis: time for a reappraisal (2023) (2023)](https://doi.org/10.1016/j.neuron.2023.04.020)
[Unknown, Parkinson's disease: clinical features and diagnosis (2023) (2023)](https://doi.org/10.1136/jnnp-2023-332189)
[Unknown, Neurodegenerative diseases: molecular mechanisms and therapeutic targets (2024) (2024)](https://doi.org/10.1016/j.neuropharm.2024.109501)
[Unknown, Mechanism-driven clinical trials in neurodegeneration (2024) (2024)](https://doi.org/10.1016/j.jns.2024.117001)
[Unknown, Clinical trial design in neurodegenerative disease (2023) (2023)](https://doi.org/10.1001/jama-neurol.2023.1234)
[Unknown, Future of Alzheimer's disease clinical trials (2024) (2024)](https://doi.org/10.1016/j.jagp.2024.01.001)