By Peter Loftus
Researchers will provide clues this week about whether Eli Lilly
& Co.'s risky bet on an experimental drug for Alzheimer's
disease ultimately pays off-for patients and for Lilly's bottom
line.
Scientists are scheduled to present results from a clinical
trial of the drug, solanezumab, at the Alzheimer's Association
International Conference in Washington. The outcomes will help
signal whether Lilly's drug can overcome earlier, negative studies
and become the first marketed treatment to slow the worsening of
the underlying disease. Current treatments for Alzheimer's can
alleviate symptoms but don't slow underlying disease
progression.
The dementia-causing brain disorder afflicts an estimated five
million Americans, but has been a tough disease for the drug
industry to crack because scientists don't fully understand what
causes it. Companies have scrapped many experimental drugs that
initially looked promising but failed to significantly slow
deterioration of memory and other cognitive and daily-living skills
of Alzheimer's patients in clinical trials.
Despite the setbacks, the industry continues to hunt for better
treatments because of the limitations of current options. And a
huge market opportunity awaits drugs that can slow or halt disease
progression. Jefferies & Co. analyst Jeffrey Holford estimates
the Lilly drug could generate peak annual sales of more than $3
billion world-wide if it is approved for marketing by
regulators.
Anticipation of the Lilly Alzheimer's data is a big reason why
Lilly shares have risen 26% year-to-date and recently hit a decade
high. Positive results would bolster the outlook for the
Indianapolis company's sales and earnings as it tries to move past
patent expirations for older blockbusters.
A leading theory in Alzheimer's research is that the buildup of
a sticky protein known as beta amyloid in the brain contributes to
the disease. Lilly's solanezumab is designed to bind to amyloid and
clear it from the brain. It is an antibody that is infused
intravenously.
But Lilly's effort is risky because solanezumab-like most other
amyloid-targeting drugs-had mostly negative results in earlier
studies. In two large clinical trials reported in 2012, the drug
failed to significantly slow the decline of cognition and
functional abilities among the overall population of patients with
mild to moderate Alzheimer's, compared with a placebo.
Lilly scientists, however, saw a ray of hope because the drug
appeared to slow cognitive decline in a subgroup: patients with a
mild form of the disease. Seizing on that signal, Lilly decided to
continue developing the drug in mild Alzheimer's patients despite
the high costs.
Lilly hasn't disclosed total costs of developing the drug, but
Eric Siemers, a lead Lilly Alzheimer's researcher, said large
studies like the ones Lilly has conducted typically cost "well over
$100 million."
The company started a new clinical study in 2013, targeting
enrollment of about 2,100 patients with mild Alzheimer's and due to
be completed by the end of 2016. This ongoing study compares
solanezumab with a placebo, and its outcome will determine whether
Lilly submits the drug for marketing approval in the U.S. and
elsewhere.
The results due out this week aren't from that new study, but
from an extension of the two studies that were reported in 2012.
Lilly continued to provide the drug to some patients who received
it in the original studies, and allowed patients who originally
received a placebo in those studies to switch over to
solanezumab.
On Wednesday, researchers will present data on mild Alzheimer's
patients from those extension studies. They will compare outcomes
of patients who have been taking solanezumab since the start of the
original studies, with those who switched over after taking
placebo. On average, the placebo patients started taking
solanezumab about 18 months after the earlier patients.
In theory, if solanezumab is slowing the loss of brain cells as
Lilly hopes, the patients who started therapy later shouldn't be
able to "catch up" to the patients who started earlier, in
cognition or function. If there is no catch-up, that would be a
sign the Lilly drug is changing the underlying pathology of the
disease.
But if there is no significant difference in patient outcomes
between these groups, it may be a sign that the drug isn't having
the hoped-for effect on the underlying disease, and instead merely
easing symptoms.
Other drug companies have also focused their amyloid-targeting
drugs on early-stage Alzheimer's patients, and will be closely
watching the Lilly results.
Write to Peter Loftus at peter.loftus@wsj.com
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