Misleading headline. What they actually demonstrated is reversing amyloid accumulation and the cognitive deficits in a transgenic mouse whose pathology is essentially just amyloid accumulation. Calling that "reversing Alzheimer's" treats amyloid buildup and the disease as the same thing, which is exactly the conflation the amyloid hypothesis has been criticised for over the last decade.
Alzheimer's in humans is amyloid + tau tangles + neuroinflammation + vascular dysfunction + actual neurodegeneration (entorhinal and hippocampal neurons dying, brain volume measurably dropping on MRI). Tau burden correlates with cognitive decline far better than amyloid does. The IBEC paper addresses one of those layers, the upstream-ish one, in a model that doesn't reproduce most of the others. Fixing a cause in a young system before damage has accumulated is just not the same operation as fixing an established disease in an old human cortex that's already lost the cells.
The human translation data backs this up. Lecanemab clears plaques and slows cognitive decline by about 27% over 18 months. Donanemab clears around 76% of plaques and slows decline by ~35% in early AD. In both trials both arms still declined, treatment just declined a bit more slowly. Northwestern's Mesulam Institute puts it bluntly: "These medications do not reverse existing disease or stop the progression." So removing amyloid in a system that already has the full human pathology bends the curve, it doesn't undo anything.
What the IBEC team has here is a genuinely interesting result for the cerebrovascular angle, where BBB dysfunction and glymphatic clearance failure are upstream of plaque accumulation rather than a downstream consequence. The LRP1 transport mechanism and the multivalent ligand design are clever and well-grounded. The fair claim is "we improved amyloid clearance and rescued behavioural deficits in an amyloid-overexpressing mouse by targeting BBB transport." That's a real contribution. "Reversed Alzheimer's" sells the mechanism by overstating what it did, and it sets up the same disappointment cycle the field has been through with every other anti-amyloid intervention that worked great in mice.
Original paper, for anyone wanting the actual data: https://doi.org/10.1038/s41392-025-02426-1