But those hopes were dashed when
the drug failed in its first late-stage clinical trial, dealing a blow not only
to patients with Alzheimer’s and their families but to the companies developing
the treatment — a San Francisco start-up called Medivation and
the drug giant Pfizer.
The companies said in a statement that the drug, called
Dimebon, had shown virtually no effect in treating the cognitive decline or
behavioural problems associated with Alzheimer’s when compared with a placebo.
The result was somewhat surprising,
because in a smaller previous trial, Dimebon had shown more effectiveness than
any of the drugs already approved for Alzheimer’s disease. It seemed to improve
cognitive function or at least stave off mental decline for about 18 months,
while the existing treatments do so for only about six months, experts said.
As recently as last week, an
Alzheimer’s researcher had said of Dimebon, “The clinical data is by far and
away superior to anything that’s ever been shown before.” That researcher, Mark
A. Smith, of Case Western Reserve University, has been trying to help
Medivation figure out how the drug works.
Still, some doctors and Wall Street
investors had been a bit sceptical, because that earlier trial had been done in
Russia, making it hard to determine how the study was conducted. Also, the mechanism
by which the drug worked was never clear.
The sceptics were borne out by the
results of the new trial, called Connection, which involved 598 patients with
mild to moderate Alzheimer’s disease in Europe and in North and South America.
“The results from the Connection
study are unexpected, and we are disappointed for the Alzheimer’s community,”
Dr. David Hung, the chief executive of Medivation, said in a statement. “We are
working with our colleagues at Pfizer to better understand the Connection