Alzheimers Disease, Familial

The purpose of this research study is to test the study drug, referred to as remternetug, to determine its effectiveness for the study treatment of asymptomatic (at risk) Alzheimer disease in individuals with AD-causing mutations. This study will also investigate the effects of remternetug on biomarkers (measures of the disease including brain scans, blood and spinal fluid tests), examine safety data to identify any potential benefits or risks, and examine how well participants can tolerate remternetug. Stage 1 will determine if treatment with the study drug prevents or reverses amyloid beta (Aβ) accumulation compared with placebo in participants with dominantly inherited Alzheimer's disease (DIAD). Stage 2 will evaluate the effect of early anti-amyloid treatment on downstream biomarkers of AD in treated participants compared to external control groups.

The purpose is to evaluate the biomarker effect, safety, and tolerability of investigational study drugs in participants who are known to have an Alzheimer's disease (AD)-causing mutation. Stage 1 will determine if treatment with the study drug prevents or slows the rate of amyloid beta (Aβ) pathological disease accumulation demonstrated by Aβ positron emission tomography (PET) imaging. Stage 2 will evaluate the effect of early Aβ plaque reduction/prevention on disease progression by assessing downstream non-Aβ biomarkers of AD (e.g., CSF total tau, p-tau, NfL) compared to an external control group from the DIAN-OBS natural history study and the DIAN-TU-001 placebo-treated participants.