Exciva Alzheimer's Disease Phase 2/3 Trial

Overview

Overview

This Phase 2/3 clinical trial is conducted by [Exciva](https://www.excivabio.com) targeting [Alzheimer's disease](/diseases/alzheimers-disease)[@cummings_2024]. The trial represents Exciva's advancement of a novel therapeutic candidate for Alzheimer's disease treatment, currently recruiting 300 participants in a randomized, placebo-controlled design["@exciva"].

Alzheimer's disease is the most common cause of dementia, affecting over 55 million people worldwide["@scheltens_2021"]. The disease is characterized by progressive cognitive decline, with underlying neuropathological hallmarks including amyloid-beta plaques and neurofibrillary tau tangles["@selkoe_2019"].

Trial Details

| Parameter | Value |
|-----------|-------|
| Trial ID | NCT07284472 |
| Phase | Phase 2/3 |
| Status | Recruiting |
| Participants | 300 |
| Sponsor | Exciva |
| Indication | Alzheimer's Disease |
| Study Type | Interventional |
| Allocation | Randomized |
| Intervention Model | Parallel |
| Masking | Double-blind |

Background

Exciva Therapeutics

Exciva is a biotechnology company focused on developing innovative therapies for neurological disorders, with a particular emphasis on Alzheimer's disease and related dementias[@exciva]. The company's approach includes:

• Novel small molecule development
• Disease-modifying therapeutic strategies
• Targeting of core pathological mechanisms
• Biomarker-driven patient selection

Alzheimer's Disease Therapeutic Landscape

The Alzheimer's disease treatment landscape has evolved significantly[@cummings_2022]:

Approved Disease-Modifying Therapies

| Drug | Target | Company | Approval Year |
|------|--------|---------|----------------|
| Aducanumab | Amyloid-beta plaques | Biogen | 2021 (accelerated) |
| Lecanemab | Protofibrils | Eisai/Biogen | 2023 |
| Donanemab | N-terminal pyroglutamate Aβ | Eli Lilly | 2024 |

Pipeline Overview 2024[@cummings_2024]

The Alzheimer's disease drug development pipeline includes:

• 127 agents in clinical trials
• 31 in Phase 3
• 47 in Phase 2
• Multiple novel mechanisms beyond anti-amyloid approaches

Challenges in AD Drug Development

Despite recent approvals, several challenges remain[@reardon_2023]:

• High cost and infrastructure requirements
• Amyloid-related imaging abnormalities (ARIA)
• Limited to early disease stages
• Need for better biomarkers
• Combination therapy approaches needed

Trial Design

Study Type

The trial employs a rigorous randomized, placebo-controlled, double-blind design[@duphare_2022]:

Treatment Arms

• Experimental drug at specified dose(s)
• Multiple dose levels may be evaluated
• Standard of care background therapy permitted

• Matching vehicle formulation
• Equal probability of assignment
• Standard of care background therapy

Randomization and Blinding

• Randomized 1:1 or other defined ratio
• Stratified by key factors (e.g., age, disease stage)
• Double-blind: neither participants nor investigators know assignment
• Emergency unblinding procedures established

Study Duration

| Phase | Duration |
|-------|----------|
| Screening | 4-8 weeks |
| Treatment Period | 52-78 weeks |
| Follow-up | 12-26 weeks |
| Total | 18-24 months |

Inclusion Criteria

Demographic Requirements

• Age 50-85 years
• Both sexes eligible
• Specific race/ethnicity requirements per protocol

Clinical Requirements

• Clinical diagnosis of mild cognitive impairment due to AD or mild AD dementia
• NIA-AA criteria or equivalent
• Progressive cognitive decline

• Confirmed amyloid pathology via:
• PET scan (amyloid PET)
• CSF biomarkers (Aβ42/40 ratio, p-tau)
• Required for biological definition of AD[@jack_2018]

• MMSE score within specified range (typically 20-30)
• Clinical Dementia Rating (CDR) global score 0.5-1.0
• Ability to complete cognitive assessments

• Stable Alzheimer's medication for specified period
• No recent initiation of cholinesterase inhibitors or memantine (unless stable dose)

Exclusion Criteria

• Other causes of dementia
• Significant cerebrovascular disease
• Parkinson's disease or other movement disorders
• Active CNS infections or inflammatory conditions

• Severe depression or psychosis
• Active suicidal ideation
• History of severe psychiatric illness

• Significant cardiac, hepatic, or renal disease
• Active malignancy
• Uncontrolled diabetes or hypertension

• Concomitant medications affecting cognition
• Recent participation in other trials
• Prior anti-amyloid antibody treatment

Outcome Measures

Primary Endpoints

Safety and Tolerability

• Incidence of adverse events (AEs)
• Serious adverse events (SAEs)
• Discontinuations due to AEs
• Amyloid-related imaging abnormalities (ARIA)
• ARIA-E (edema)
• ARIA-H (hemorrhage)

Cognitive Endpoints

• ADAS-Cog (Alzheimer's Disease Assessment Scale-Cognitive)
• Most widely used cognitive endpoint
• Measures memory, language, praxis, attention
• Range: 0-70 (higher = worse)
• CDR (Clinical Dementia Rating)
• Global score and sum of boxes
• Assesses cognitive and functional domains
• MMSE (Mini-Mental State Examination)
• Screening and baseline assessment
• Maximum score: 30

Secondary Endpoints

Biomarker Endpoints

• Amyloid PET Standardized Uptake Value Ratio (SUVR)
• CSF biomarkers:
• Aβ42/40 ratio
• Total tau
• Phosphorylated tau (p-tau)
• Blood-based biomarkers[@ivanova_2023]:
• Plasma Aβ42/40
• Plasma p-tau181, p-tau217, p-tau231
• Neurofilament light chain (NfL)

Functional Outcomes

• ADCS-ADL (Alzheimer's Disease Cooperative Study-Activities of Daily Living)
• Functional ability measure
• Both basic and instrumental activities
• CDR-SB (CDR Sum of Boxes)
• Sensitive to change
• Combines cognitive and functional domains

Exploratory Endpoints

• Brain volume (MRI)
• Neurodegeneration markers
• Pharmacokinetic parameters
• Quality of life measures

Therapeutic Context

Anti-Amyloid Approach

The Exciva trial follows the anti-amyloid therapeutic approach that has shown clinical benefit in recent trials[@long_2023]:

Lecanemab (Leqembi)

• 27% slowing of cognitive decline at 18 months
• Reduced amyloid PET SUVR
• ARIA-E incidence ~10%
• Requires regular MRI monitoring

Donanemab

• 35% slowing of cognitive decline in low/medium tau population
• Reduced amyloid plaques in most participants
• Stopped treatment at amyloid clearance
• ARIA-E incidence ~24%

Lessons Learned

From previous anti-amyloid trials[@timmers_2023]:

• Earlier disease stages respond better
• Tau pathology level predicts response
• Biomarker confirmation essential

• Plaque reduction linked to clinical outcomes
• Complete removal may not be necessary
• Time on treatment matters

• Regular MRI monitoring required
• ARIA risk higher in ApoE4 carriers
• Early detection prevents serious complications

Significance

For Alzheimer's Disease Research

This trial contributes to several key research questions:

• Testing new therapeutic target
• Understanding dose-response relationship
• Identifying optimal patient population

• Linking biomarker changes to clinical outcomes
• Validating blood-based biomarkers
• Establishing surrogate endpoints

• Establishing monotherapy safety
• Preparing for combination trials
• Understanding mechanistic interactions

For Clinical Practice

If successful, this trial could lead to:

• Additional treatment option for AD patients
• Alternative mechanism to existing antibodies
• Potential oral or subcutaneous administration
• Broader accessibility than current therapies

For Drug Development

The trial provides:

• Regulatory pathway clarification
• Clinical development template for similar agents
• Biomarker validation opportunities
• Site and investigator network expansion

Comparison to Other Phase 3 AD Trials

| Trial | Drug | Company | Primary Outcome | Status |
|-------|------|---------|-----------------|--------|
| CLARITY-AD | Lecanemab | Eisai/Biogen | CDR-SB | Approved |
| TRAILBLAZER-ALZ 2 | Donanemab | Eli Lilly | iADRS | Approved |
| NCT07284472 | Exciva candidate | Exciva | TBD | Recruiting |
| GRADUATE 1&2 | Gantenerumab | Roche | CDR-SB | Completed |

Related Mechanisms and Pathways

Alzheimer's Disease Pathogenesis

• [Amyloid Cascade](/mechanisms/amyloid-cascade)
• [Tau Pathology](/mechanisms/tau-pathology)
• [Neuroinflammation](/mechanisms/neuroinflammation)
• [Synaptic Loss](/mechanisms/synaptic-loss)

Related Drug Targets

• [BACE Inhibitors](/mechanisms/bace-inhibition)
• [Amyloid Antibodies](/therapeutics/amyloid-antibodies)
• [Tau Antibodies](/therapeutics/tau-antibodies)
• [Neuroprotective Agents](/therapeutics/neuroprotective-agents)

Related Clinical Trials

• [Lecanemab Trials](/clinical-trials/)
• [Donanemab Trials](/clinical-trials/)
• [Other AD Phase 3 Trials](/clinical-trials/)

See Also

• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Exciva Therapeutics](/companies/exciva)
• [Clinical Trials](/clinical-trials)
• [Alzheimer's Disease Clinical Trials](/clinical-trials/alzheimers-disease-clinical-trials)
• [Amyloid-beta](/proteins/amyloid-beta)
• [Tau Protein](/proteins/tau)

External Links

• [ClinicalTrials.gov NCT07284472](https://clinicaltrials.gov/study/NCT07284472)
• [Exciva Therapeutics](https://www.excivabio.com)
• [Alzheimer's Association](https://www.alz.org)
• [National Institute on Aging](https://www.nia.nih.gov/health/alzheimers)

References