On 27 July, Mercè Boada and coinvestigators published primary results from the AMBAR study in the Alzheimer’s and Dementia journal, showing some cognitive and functional benefit of albumin replacement therapy in Alzheimer’s disease (AD). Albumin replacement therapy involves the intravenous extraction of blood plasma and the infusion of an albumin solution, in a process known as ‘plasma exchange’ or PE. The AMBAR study was based on the hypothesis that PE and albumin replacement therapy could help reduce levels of amyloid beta proteins, thanks to the ability of plasma albumin to bind and sequester this harmful protein.
The AMBAR (Alzheimer Management By Albumin Replacement) study was a phase 2b/3 randomised, placebo-controlled clinical trial, enrolling participants with mild to moderate AD in Spain and in the US. Initiated in 2011, AMBAR screened 496 people with mild/moderate AD, randomising 347 participants to one of four treatment arms: three arms with plasma exchange and albumin replacement at increasing doses, and one sham or placebo arm. AMBAR participants received weekly PE for a 6-week period, followed by a year of monthly infusions.
The co-primary outcomes of AMBAR were functional and cognitive status at 14 months, as measured by the ADCS-ADL and ADAS-Cog neuropsychological tests. Analyses showed a significant reduction in functional and cognitive decline in participants receiving PE, with 52% and 66% reductions in decline. Subgroup analysis revealed some differences in the scale of treatment benefit between participants based on their AD severity at baseline: in particular, participants with moderate AD experienced greater improvements in cognitive status on the ADAS-Cog scales compared to those with mild AD.
https://alz-journals.onlinelibrary.wiley.com/doi/full/10.1002/alz.12137
