AV-1980R (Tau Vaccine) in Preclinical Alzheimer's Disease (TAURUS-1980)

This study will evaluate AV-1980R, a MultiTEP-based active immunotherapy formulated with Advax-CpG55.2 adjuvant, in participants with preclinical Alzheimer's disease. Up to 48 participants aged 65 to 80 years will be randomized in a 3:1 ratio to receive AV-1980R or placebo in three ascending-dose cohorts of 20 µg, 60 µg, and 180 µg. Participants will receive three intramuscular injections at Weeks 0, 4, and 38, with follow-up visits through Week 58. The primary objective is to evaluate safety and tolerability. Secondary objectives include evaluation of anti-tau antibody responses and T-cell responses. Exploratory assessments include plasma Alzheimer's disease biomarkers, tau PET imaging, immune-response characteristics, and cognitive measures.