AAIC 2026: Neuro Doc Sounds Constructive on Phase II Tau Data in Alzheimer‘s

Research evidence excerpt

AAIC 2026: Neuro Doc Sounds Constructive on Phase II Tau Data in Alzheimer‘s

ly in 2028. Regarding

the four-year duration of AHEAD 3-45, he believes the study's enrichment strategy which focuses on

cognitively normal but amyloid-positive individuals (many of whom carry APOE4 risk alleles) should

meaningfully increase event rates and improve the study's ability to detect treatment effects despite

the relatively slow progression of preclinical disease.

When discussing amyloid imaging, Dr. Rosenbloom noted that he generally considers amyloid

burden above ~40 Centiloids to represent clearly elevated pathology, 20-40 Centiloids as an

intermediate range, and values below ~20 Centiloids as generally amyloid-negative. In practice, he

typically uses a threshold of approximately 25 Centiloids when assessing amyloid positivity. More

broadly, he believes the field is moving toward increasingly sophisticated biological staging rather

than simply defining patients as amyloid-positive or amyloid-negative. In his view, combining amyloid

measures with emerging tau biomarkers, including tau PET and MTBR-tau243, will ultimately allow

clinicians to identify individuals most likely to benefit from specific interventions and intervene earlier

in the disease course.

On ARIA risk, Dr. Rosenbloom does not expect preclinical populations to be insulated from

treatment-related risk simply because they are asymptomatic. His rationale is that ARIA is driven

primarily by underlying cerebrovascular amyloid rather than clinical disease stage, and he noted that

a substantial proportion of individuals with Alzheimer's pathology already harbor vascular amyloid

deposition before symptoms emerge. In his view, the biological substrate that predisposes patients