The emerging role of CETP inhibition in the prevention of Alzheimer's disease.

We recently showed that patients with atherosclerotic cardiovascular disease (ASCVD) carry a substantial but largely unrecognized burden of early Alzheimer's disease (AD) pathology. In the BROADWAY pivotal phase 3 lipid-lowering trial, nearly half of participants with high-risk ASCVD had plasma p-tau217 concentrations above thresholds associated with preclinical AD, yet none had undergone evaluation for cognitive impairment. In this population, apolipoprotein E ε4 (APOE4) carriers were disproportionately represented among those with the highest p-tau217 levels. These findings expose a critical gap between cardiovascular care and dementia prevention and raise the question whether interventions targeting shared pathophysiology could address both conditions simultaneously. Cholesteryl ester transfer protein (CETP) inhibition has emerged as a candidate for this dual role. In BROADWAY, obicetrapib reduced p-tau217 progression across the study population, with effects most pronounced in APOE4 carriers. In fact, treatment differences favoring obicetrapib were observed across all measured AD biomarkers in high-risk subgroups, including neurofilament light chain, glial fibrillary acidic protein, and the amyloid-beta (Aβ) 42:40 ratio. Unlike approaches that target downstream pathology, such as amyloid plaques already deposited in the brain or the inflammatory consequences of established disease, CETP inhibition may address the upstream processes involved in initiating the pathological cascade: lipid dysregulation, cholesterol ester accumulation in glial cells, impaired cholesterol efflux, lipid peroxidation, oxysterol formation, and deficient antioxidant transport. This review examines the biological rationale linking APOE4 status to disordered lipid metabolism in both peripheral and central compartments, the genetic and epidemiological evidence supporting CETP as a therapeutic target, the mechanisms through which CETP inhibition might confer neuroprotection, and the clinical data suggesting obicetrapib as the first oral agent associated with favorable changes in AD biomarkers across both amyloid and tau axes in individuals at high genetic risk for the development of AD.