Clinical trial
AMBAR (Alzheimer's Management By Albumin Replacement)
Last updated Sat May 30 2026 00:00:00 GMT+0000 (Coordinated Universal Time)
Design
496 patients with mild-moderate Alzheimer’s randomised to one of three plasma-exchange protocols or placebo (sham apheresis):
- 6 weekly conventional plasma exchanges, then monthly for 12 months.
- Same with low- and high-dose albumin replacement.
- Sham.
Funded by Grifols (manufacturer of albumin replacement products).
Findings
- Mild AD: no significant cognitive benefit on primary endpoint.
- Moderate AD: ~66% slower progression on ADAS-Cog over 14 months.
- CSF amyloid-β: increased (suggesting clearance into plasma).
- Tau: decreased in CSF.
- Functional outcomes: improved in moderate AD.
Why it matters
AMBAR is the largest controlled trial of a plasma-based intervention in Alzheimer’s. The moderate-AD signal is intriguing, supporting the broader hypothesis that systemic factors influence neurodegeneration and that removing pro-aging circulating factors (Conboy-style) may help.
Limitations: industry sponsorship, mixed primary endpoint, requires infrastructure for chronic plasmapheresis.
What followed
Multiple smaller TPE-in-aging trials launched. Some commercial longevity clinics offer TPE protocols extrapolating from AMBAR; the evidence is preliminary outside AD.
Related entries
Plasma exchange, Alzheimer's disease, Irina & Michael Conboy.
References
- Boada, M. et al. A randomized, controlled clinical trial of plasma exchange with albumin replacement for Alzheimer's disease: primary results of the AMBAR study. Alzheimers Dement. 16, 1412–1425 (2020).