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.
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.
| 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 |
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:
- 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 metabolism
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.
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 progression
Growing 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.
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 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.
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
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.
¶ 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
- Semaglutide + Background Arm: Oral semaglutide plus stable AD background therapy
- Placebo + Background Arm: Oral placebo plus stable AD background therapy
Allowed background therapies include:
- Acetylcholinesterase inhibitors (donepezil, rivastigmine, galantamine)
- Memantine
- Combination of both
- 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
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
- 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 procedures
- 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 pancreatitis
¶ Primary and Secondary Endpoints
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
-
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
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 expansion
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 care
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 |
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)
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
The trial includes comprehensive safety monitoring:
- Regular physical examinations
- Laboratory assessments including lipase/amylase
- Adverse event documentation
- Imaging for pancreatitis symptoms
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
Core CSF biomarkers:
- Aβ42/40 ratio: Amyloid pathology
- Phosphorylated tau: Tau pathology
- Total tau: Neurodegeneration
- Neurofilament light: Axonal injury
Blood-based markers for monitoring:
- NfL: Neurodegeneration marker
- GFAP: Astrocyte activation
- p-tau181: Tau pathology
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.
¶ Proteins and Genes