Another Phase III failure shakes amyloid beta model of Alzheimer's

In what may be viewed as another nail in the coffin of the once-dominant “amyloid beta” theory of Alzheimer’s disease, collaborators Biogen (Nasdaq: BIIB) and Eisai (TYO: 4523) have announced a Phase III failure for the oral BACE inhibitor elenbecestat.

The firms announced they are discontinuing the MISSION AD1 and AD2 studies, which have been evaluating the candidate in people with early Alzheimer’s disease. The long-term extension of the Phase II clinical trial of elenbecestat will also be discontinued.

Analysts SVB Leerink said the new was "widely expected (predicted) by the investment community," and that it "amounts to a further step in the unwinding of Biogen’s expensive, painful and ultimately fruitless investment in Alzheimer’s disease drug development."