A potential Alzheimer’s drug that had seemed to perform
spectacularly well in a medium-scale clinical trial has now been
shown in a larger and more conclusive trial to have no apparent
effect on the disease. The surprising failure of the drug, known
as dimebon, is yet another disappointment for Alzheimer’s
researchers as well as patients and their families. It also
raises questions about the conduct and design of Alzheimer’s
clinical trials, particularly in Russia where the initial
dimebon trial took place. “The prior doubts about the Russian
trial appear to have been borne out,” says Sam Gandy, an
Alzheimer’s researcher at Mount Sinai School of Medicine.
Dimebon (generic name latrepirdine) was originally developed and
briefly used as an antihistamine in Russia in the 1980s. It
began to be re-evaluated as a potential Alzheimer’s drug in the
1990s, after Russian researchers reported that it seemed to
boost the levels of memory-related neurotransmitters in lab
tests on brain cells. A San Diego-based company, Me