ALZ-801 Phase 3 APOLLOE4 Extension Trial

Overview

NCT06304883 is a long-term extension Phase 3 trial evaluating ALZ-801 (valiltramiprosate), an oral amyloid aggregation inhibitor, in subjects with early Alzheimer's disease who are homozygous for the APOE4 allele (APOE4/4 genotype). This extension study builds upon the earlier APOLLOE4 Phase 3 trial to assess long-term efficacy, safety, and biomarker effects[@hey2020][@vergelli2021].

ALZ-801 represents a first-in-class oral small molecule approach that differs from monoclonal antibody therapies by directly targeting toxic amyloid-beta oligomers rather than clearing existing plaques. This mechanism may offer advantages including no ARIA (amyloid-related imaging abnormalities) risk and easier chronic dosing[@parthasarathy2022].

Trial Details

| Parameter | Value |
|-----------|-------|
| NCT Number | NCT06304883 |
| Phase | Phase 3 |
| Status | Active, not recruiting |
| Sponsor | Alzheon Inc. |
| Enrollment | 163 patients |
| Study Type | Interventional |
| Start Date | April 2, 2024 |
| Expected Completion | January 2027 |
| Duration | Up to 2.5 years |
| Location | United States (Arizona, California) |

Mechanism of Action

ALZ-801 (valiltramiprosate) is an oral small molecule that targets amyloid-beta oligomerization through a unique mechanism:

Molecular Target

• Primary Target: Soluble amyloid-beta (Aβ) oligomers
• Mechanism: Allosteric modulation of Aβ aggregation kinetics
• Action: Stabilizes non-toxic Aβ conformations, prevents formation of toxic oligomers

Overview

NCT06304883 is a long-term extension Phase 3 trial evaluating ALZ-801 (valiltramiprosate), an oral amyloid aggregation inhibitor, in subjects with early Alzheimer's disease who are homozygous for the APOE4 allele (APOE4/4 genotype). This extension study builds upon the earlier APOLLOE4 Phase 3 trial to assess long-term efficacy, safety, and biomarker effects[@hey2020][@vergelli2021].

ALZ-801 represents a first-in-class oral small molecule approach that differs from monoclonal antibody therapies by directly targeting toxic amyloid-beta oligomers rather than clearing existing plaques. This mechanism may offer advantages including no ARIA (amyloid-related imaging abnormalities) risk and easier chronic dosing[@parthasarathy2022].

Trial Details

| Parameter | Value |
|-----------|-------|
| NCT Number | NCT06304883 |
| Phase | Phase 3 |
| Status | Active, not recruiting |
| Sponsor | Alzheon Inc. |
| Enrollment | 163 patients |
| Study Type | Interventional |
| Start Date | April 2, 2024 |
| Expected Completion | January 2027 |
| Duration | Up to 2.5 years |
| Location | United States (Arizona, California) |

Mechanism of Action

ALZ-801 (valiltramiprosate) is an oral small molecule that targets amyloid-beta oligomerization through a unique mechanism:

Molecular Target

• Primary Target: Soluble amyloid-beta (Aβ) oligomers
• Mechanism: Allosteric modulation of Aβ aggregation kinetics
• Action: Stabilizes non-toxic Aβ conformations, prevents formation of toxic oligomers

Key Differentiation from Antibodies

Unlike anti-amyloid monoclonal antibodies (lecanemab, donanemab, aducanumab), ALZ-801:

• Is an oral small molecule (not IV infusion)
• Targets oligomer formation rather than clearing plaques
• Has not shown ARIA risk in clinical trials
• May be suitable for combination therapy[@hey2020]

Patient Population

Inclusion Criteria

• Diagnosis: Early Alzheimer's disease (MCI or mild dementia)
• Genotype: APOE4/4 homozygous (both alleles)
• MMSE Score: 20-30
• CDR Score: 0.5-1.0
• Prior Trial: Completed earlier ALZ-801 Phase 3 APOLLOE4 trial

Target Population Rationale

APOE4 homozygous patients represent a genetically defined subgroup with:

• Higher amyloid burden at earlier ages
• More rapid disease progression
• Greater therapeutic response to ALZ-801 observed in Phase 2 trials
• Potentially greater benefit from disease-modifying therapy[@abushakra2021]

Study Design

Extension Structure

This long-term extension study allows subjects who completed the initial APOLLOE4 trial to continue receiving ALZ-801 treatment:

Primary Endpoints

• Cognitive Efficacy 1: Change from baseline on cognitive scale
• Cognitive Efficacy 2: Additional cognitive endpoint
• Safety: Incidence, nature, and severity of treatment-emergent adverse events (TEAEs)

Biomarker Assessments

Key biomarker measures include:

• CSF amyloid-beta 42 levels
• Plasma p-tau217
• Amyloid PET (centiloids)
• Neurofilament light chain (NfL)
• Hippocampal volume (MRI)

Clinical Evidence to Date

Phase 2 Trial Results

The Phase 2 trial demonstrated[@vergelli2021][@abushakra2021]:

Efficacy:

• Statistically significant cognitive benefit in APOE4 carriers
• Reduced CSF amyloid-beta 42 (indicator of reduced oligomer formation)
• Stabilization of hippocampal volume
• Reduced tau pathology markers

• Favorable safety and tolerability profile
• No ARIA observed
• Low discontinuation rate

Publication

A 2024 publication in the Journal of Prevention of Alzheimer's Disease comprehensive results provided further evidence for ALZ-801's mechanism and clinical effects[@alzheon2024].

Competitive Position

ALZ-801 differs from approved anti-amyloid antibodies:

| Feature | ALZ-801 | Lecanemab | Donanemab |
|---------|---------|-----------|-----------|
| Route | Oral | IV infusion | IV infusion |
| Target | Oligomer formation | Protofibrils | Pyroglutamate Aβ |
| ARIA Risk | None observed | Yes | Yes |
| Dosing Frequency | Daily | Biweekly | Monthly |
| Genetic Selection | APOE4/4 required | Optional | Optional |

Future Outlook

Regulatory Timeline

• Expected trial completion: 2027
• Potential NDA filing: 2028
• FDA Fast Track designation: Granted

Development Program

If successful, ALZ-801 could represent:

• First oral disease-modifying AD therapy
• Combination opportunity with anti-amyloid antibodies
• Treatment option for patients unable to tolerate antibodies
• Broader population studies planned (non-APOE4/4)

See Also

• [Anti-Amyloid Therapeutics](/therapeutics/anti-amyloid-therapeutics)
• [ALZ-801 (Valiltramiprosate) Trial Overview](/companies/alzheon)
• [Clinical Trials Index](/clinical-trials)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [APOE4 Gene](/genes/apoe)

References