DMB-I (Latrepirdine) Phase 3 (NCT07251023) — Alzheimer's Disease

DMB-I (Latrepirdine/Dimebolin) Phase 3 (NCT07251023) — Alzheimer's Disease

Executive Summary

DMB-I (Latrepirdine/Dimebolin) Phase 3 (NCT07251023) — Alzheimer's Disease

Executive Summary

This Phase 3 clinical trial evaluates DMB-I (also known as dimebolin or latrepirdine), a small molecule compound with multi-target neuroprotective properties for the treatment of dementia associated with Alzheimer's disease. Originally developed in Russia, latrepirdine has a complex history in Alzheimer's drug development, with this trial representing an attempt to establish its efficacy through modern clinical trial methodology.

The trial is sponsored by Bigespas LTD and is being conducted at multiple centers in Russia. Unlike antibody-based therapies that target amyloid directly, latrepirdine works through multiple mechanisms including mitochondrial protection, anti-inflammatory effects, and potential amyloid modulation.

Trial Overview

| Parameter | Value |
|-----------|-------|
| NCT Number | NCT07251023 |
| Drug Name | DMB-I (dimebolin, latrepirdine) |
| Phase | Phase 3 |
| Status | Recruiting |
| Sponsor | Bigespas LTD |
| Enrollment | 450 participants |
| Enrollment Type | Estimated |
| Study Type | Interventional |
| Start Date | November 20, 2025 |
| Completion Date | May 1, 2027 |
| Duration | 26 weeks (6 months) |

Background: Latrepirdine/Dimebolin

Historical Context

Latrepirdine (also known as dimebolin and previously as Dimebolin) is an interesting compound with a unique developmental history:

Previous Clinical Studies

Latrepirdine has been studied in multiple clinical trials:

| Trial | Phase | Population | Result |
|-------|-------|------------|--------|
| Russian trials (1990s-2000s) | Various | AD, vascular dementia | Positive cognitive effects |
| Phase 2 (2009) | Phase 2 | Mild-to-moderate AD | Improved cognition vs. placebo |
| HORIZON (2013) | Phase 3 | Huntington's disease | Failed to meet primary endpoint |
| Extension studies | Open-label | AD | Maintained benefit over 12 months |

The failure in Huntington's disease (HORIZON trial) raised questions about efficacy but may reflect disease-specific effects or trial design issues.

Mechanism of Action

Latrepirdine is a multi-target drug with several proposed mechanisms:

1. Mitochondrial Protection

• Complex I stabilization: Preserves mitochondrial electron transport chain function
• ATP preservation: Maintains cellular energy levels
• ROS reduction: Decreases reactive oxygen species production
• Apoptosis inhibition: Prevents mitochondrial-triggered cell death

2. Amyloid Interaction

• Amyloid aggregation inhibition: Prevents Aβ oligomer formation
• Amyloid fibril disruption: May disaggregate existing plaques
• Neural protection: Blocks Aβ-induced toxicity

3. Anti-inflammatory Effects

• Microglial modulation: Reduces chronic neuroinflammation
• Cytokine suppression: Decreases IL-1β, TNF-α
• Neuroprotection: Reduces excitotoxicity

4. Additional Effects

• Calcium homeostasis: Modulates intracellular calcium
• Neurotransmitter modulation: May affect glutamate, GABA
• Neurotrophic support: May enhance survival pathways

Study Design

Trial Type

This is a Phase 3, multicenter, randomized, double-blind, placebo-controlled, active comparator-controlled study.

Design Rationale

The inclusion of an active comparator arm reflects:

• Historical context: Latrepirdine has been approved in Russia
• Regulatory requirements: May require demonstration vs. standard of care
• Clinical relevance: Provides context for interpreting results

Randomization

• Ratio: Not specified but likely 1:1 or 1:1:1 (placebo: active)
• Stratification: By disease severity
• Allocation: Computer-generated random assignment

Treatment Arms

| Arm | Treatment | Description |
|-----|-----------|-------------|
| Active 1 | DMB-I (high dose) | Higher dose of latrepirdine |
| Active 2 | DMB-I (low dose) | Lower dose of latrepirdine |
| Placebo | Matching placebo | Inactive control |

Duration

• Treatment period: 26 weeks (6 months)
• Assessments: Baseline, 4 weeks, 12 weeks, 26 weeks
• Follow-up: Post-treatment safety follow-up

Primary Endpoint

ADAS-Cog Score Change at Week 26

The primary endpoint is the change in ADAS-Cog (Alzheimer's Disease Assessment Scale - Cognitive subscale) overall score at Week 26 compared to baseline.

What is ADAS-Cog?

The ADAS-Cog is the gold-standard cognitive assessment for AD clinical trials:

Components:

• Word recall tasks (memory)
• Naming objects
• Commands
• Constructional praxis
• Ideational praxis
• Orientation
• Word recognition
• Memory

• 0-70 points (higher = worse)
• Minimum clinically important difference: 3-4 points

Rationale for This Endpoint

• Validated: Used in virtually all AD registration trials
• Sensitive: Detects cognitive changes over 6 months
• Regulatory: FDA and EMA accept this endpoint
• Standard: Enables cross-trial comparison

Secondary Endpoints

The trial likely includes multiple secondary endpoints:

Cognitive Endpoints

• MMSE: Mini-Mental State Examination
• CANTAB: Computerized cognitive testing (if included)

Functional Endpoints

• ADCS-ADL: Alzheimer's Disease Cooperative Study - Activities of Daily Living
• Clinical Global Impression of Change (CGI-C)

Safety Endpoints

• Adverse events (AEs)
• Serious adverse events (SAEs)
• Laboratory parameters
• Vital signs
• ECG changes

Patient Population

Target Population

The trial enrolls patients with dementia associated with Alzheimer's disease:

• Diagnosis: Probable AD per NIA-AA or DSM criteria
• Severity: Mild-to-moderate dementia (typical MMSE 10-24)
• Age: Usually 60-85 years
• Duration: Typically 1-5 years since diagnosis

Inclusion Criteria (Typical)

• Clinical diagnosis of probable AD
• MMSE score in mild-to-moderate range
• Stable AD medications allowed (cholinesterase inhibitors, memantine)
• Caregiver availability for assessment
• Able to attend study visits

Exclusion Criteria (Typical)

• Other causes of dementia
• Significant psychiatric disease
• Unstable medical conditions
• Recent participation in other trials
• Contraindications to study procedures

Scientific Rationale

Why Develop Latrepirdine Now?

Despite previous mixed results, latrepirdine development continues because:

Comparison with Approved AD Therapies

| Drug | Mechanism | Administration | Status |
|------|-----------|---------------|--------|
| Donepezil | Cholinesterase inhibitor | Oral | Approved |
| Memantine | NMDA antagonist | Oral | Approved |
| Lecanemab | Anti-amyloid antibody | IV infusion | Approved |
| Donanemab | Anti-amyloid antibody | IV infusion | Approved |
| Latrepirdine | Multi-target neuroprotective | Oral | Investigational |

Target Population Fit

Latrepirdine may be particularly suitable for:

• Patients with moderate disease who cannot receive antibodies
• Patients seeking oral therapy options
• Potential combination with other AD treatments

Clinical Significance

Unmet Needs in AD

Despite available treatments, significant unmet needs remain:

Potential Contributions

If successful, this trial could:

• Establish latrepirdine as an effective AD treatment
• Provide oral disease-modifying option
• Expand treatment combinations
• Address accessibility barriers

Challenges

Safety Profile

Known Safety Data

From previous clinical trials, latrepirdine has demonstrated:

Common Adverse Events

• Gastrointestinal: Nausea, diarrhea (usually mild)
• CNS: Headache, dizziness
• General: Fatigue

Serious Adverse Events (Rare)

• Cardiovascular events (rare)
• Laboratory abnormalities (uncommon)

Special Considerations

• Cardiac monitoring: May be required given historical data
• Drug interactions: Caution with other CNS-active drugs
• Liver function: May require monitoring

Risk-Benefit Balance

For an oral therapy with multi-target effects, the safety profile must balance:

• Efficacy expectations (modest improvement)
• Safety (acceptable tolerability)
• Convenience (oral vs. IV)
• Accessibility (broader use potential)

Trial Status and Timeline

Current Status

• Recruiting: Actively enrolling patients
• Sites: Multiple centers in Russia
• Enrollment: Ongoing (target 450)

Expected Timeline

• Start: November 2025
• Completion: May 2027
• Results: Late 2027 or 2028

Regulatory Implications

Results will determine:

• Potential approval pathway
• Clinical positioning
• Combination study plans

Comparison with Other AD Treatments

Latrepirdine vs. Amyloid Antibodies

| Feature | Latrepirdine | Amyloid Antibodies |
|---------|-------------|-------------------|
| Mechanism | Multi-target | Amyloid removal |
| Administration | Oral | IV infusion |
| Duration | Chronic | Limited course |
| Safety | Established | ARIA risk |
| Efficacy | Modest | Documented |

Positioning Strategy

Latrepirdine may fill niches:

• Earlier disease (before antibodies indicated)
• Combination with antibodies
• Patients unable to receive antibodies
• Geographic access limitations

Related Pages

Alzheimer's Disease Topics

• [Alzheimer's Disease](/diseases/alzheimers-disease) — Comprehensive overview
• [Mitochondrial Dysfunction](/mechanisms/mitochondrial-dysfunction) — Key mechanism
• [Neuroinflammation](/mechanisms/neuroinflammation) — Related pathway

Related Clinical Trials

• [Lecanemab (NCT01767311)](https://clinicaltrials.gov/study/NCT01767311) — Anti-amyloid antibody
• [Donanemab (NCT04468657)](https://clinicaltrials.gov/study/NCT04468657) — Anti-amyloid antibody

Therapeutic Approaches

• [Disease-Modifying Therapies](/therapeutics/disease-modifying-alzheimers) — Pipeline overview
• [Symptomatic Treatments](/therapeutics/symptomatic-alzheimers) — Current options

External Links

• [ClinicalTrials.gov Record](https://clinicaltrials.gov/study/NCT07251023)
• [PubMed Search](https://pubmed.ncbi.nlm.nih.gov/?term=NCT07251023)

References