# EVOKE/EVOKE+ Trials

**Type:** Phase 3 clinical trials  
**Sponsor:** Novo Nordisk  
**Intervention:** Oral semaglutide 14mg (flexible dose)  
**Indication:** Early-stage symptomatic Alzheimer's disease (mild cognitive impairment or mild dementia with confirmed amyloid positivity)  
**Status:** Failed (2026)  

## Trial Design

- **Design:** Two parallel Phase 3, double-blind, placebo-controlled trials
- **Population:** n=3,808 total, ages 55-85
- **Duration:** 104 weeks primary endpoint, 156 weeks extended follow-up
- **Primary endpoints:** Cognitive and global decline measures

## Results

**Primary endpoints:** Not met in either trial. Semaglutide did not demonstrate superiority to placebo in slowing cognitive or global decline.

**Secondary endpoints:**
- No delay in time to progression to dementia (MCI subgroup, pooled analysis)
- **Biomarker findings:** Up to 10% reduction in CSF core AD biomarkers (amyloid, tau)
- Significant reductions in CSF neuroinflammation markers
- **Critical gap:** Biomarker improvements did not translate to clinical benefit

## Scientific Interpretation

The biomarker-clinical benefit dissociation suggests three possible explanations:
1. Dose insufficient to produce clinical effect despite biomarker change
2. Treatment window too late (early symptomatic disease already past intervention point)
3. Neuroinflammation/AD pathobiology not rate-limiting in this population

## Implications

**For GLP-1 CNS expansion:** Establishes mechanism specificity boundary. Semaglutide shows efficacy in addiction (VTA dopamine pathways) but not neurodegeneration (amyloid/tau pathways), indicating GLP-1 CNS effects are pathway-specific rather than universally neuroprotective.

**For Alzheimer's drug development:** Adds to evidence that biomarker improvement (even in core AD pathology markers) does not guarantee clinical benefit, raising questions about surrogate endpoint validity.

**For prevention vs. treatment:** May indicate GLP-1 has preventive rather than therapeutic value in neurodegeneration, requiring different trial design in at-risk populations.

## Timeline

- **2026-04-15** — Results published in The Lancet
- **2026-04** — Novo Nordisk announces discontinuation of 1-year extension periods for both trials

## Sources

- The Lancet (2026): "Efficacy and safety of oral semaglutide 14 mg (flexible dose) in early-stage symptomatic Alzheimer's disease (evoke and evoke+): two phase 3, randomised, placebo-controlled trials"
- Alzheimer's Drug Discovery Foundation analysis
- NeurologyLive coverage