Valiltramiprosate Treatment Associated With Biomarker Changes in People With APOE4-Linked Early Alzheimer Disease

Treatment with valiltramiprosate (ALZ-801; Alzheon, Framingham, MA), an investigational oral small-molecule inhibitor of amyloid-β (Aβ) oligomer formation, was associated with reductions in plasma Alzheimer disease (AD) biomarkers in apolipoprotein ε4/ε4 (APOE4/4) homozygotes with early AD and APOE4 carriers with mild cognitive impairment (MCI), according to an analysis of phase 3 APOLLOE4 (NCT04770220) and phase 2 trial (NCT04693520) data published in Drugs.

The analysis included plasma p-tau217, p-tau217/Aβ42, and neurofilament light chain (NfL) data from the 78-week phase 3 APOLLOE4 trial, as well as 4-year fluid biomarker data from a phase 2 study. In APOLLOE4, APOE4/4 homozygotes with early AD were randomized to receive valiltramiprosate 265 mg twice daily or placebo. The phase 2 study was an open-label biomarker trial in APOE4 carriers with early Alzheimer disease who received the same dose of valiltramiprosate.

The phase 3 APOLLOE4 trial did not meet its primary clinical endpoint in the overall population, although previously reported results showed nominally significant effects on cognition, function, and volumetric MRI measures in a prespecified MCI subgroup.

Biomarker and Clinical Correlation Data

• Baseline plasma p-tau217/Aβ42 confirmed amyloid positivity in 94% of 294 phase 3 APOE4/4 participants, including 91% of participants with MCI.
• In the overall phase 3 population, valiltramiprosate treatment showed significant reductions in plasma p-tau217 vs placebo at weeks 26, 52, and 78.
• In the phase 3 MCI subgroup, plasma p-tau217 decreased by 36% from baseline with valiltramiprosate and increased by 17% with placebo in observed case analyses.
• In the same MCI subgroup, the p-tau217/Aβ42 ratio decreased by 40% with valiltramiprosate and increased by 7% with placebo.
• At week 78 in phase 3 MCI participants, p-tau217 reductions correlated with changes in Alzheimer’s Disease Assessment Scale–Cognitive Subscale (ADAS-Cog13), the Clinical Dementia Rating Scale Sum of Boxes (CDR-SB), hippocampal volume, cortical thickness, and whole brain volume.
• Plasma NfL was significantly lower with valiltramiprosate than placebo at week 78 in phase 3 MCI participants.
• In the phase 2 APOE4 carrier study, reductions in plasma p-tau217 were sustained over 4 years.

Potential Implications for Clinical Practice

The findings may be relevant to the evolving role of blood-based biomarkers in AD drug development and patient stratification. The analysis supports continued study of p-tau217 and p-tau217/Aβ42 as tools for identifying biomarker-confirmed Alzheimer disease and for monitoring pharmacodynamic effects in trials targeting amyloid-related pathways.

Several limitations should be considered. The phase 3 biomarker analyses were based on observed cases and were not adjusted for multiplicity. The phase 2 MCI subgroup was small, and the phase 2 trial was single-arm, limiting conclusions about long-term biomarker effects without a placebo comparator. The study was funded by Alzheon, and multiple authors were employees, consultants, investigators, or advisors for the sponsor.

Source

Hey JA, Abushakra S, Power A, et al. Plasma biomarker effects of oral valiltramiprosate/ALZ-801 in early Alzheimer’s disease from phase 3 and phase 2 trials: analysis of core biomarkers and correlations with clinical and neuroimaging outcomes. Drugs. Published online 2026. doi:10.1007/s40265-026-02381-3