* Agents designed to detect tau tangles in brain
* Agents will be used first to test Alzheimer's drugs-Lilly
By Julie Steenhuysen
CHICAGO, April 17 In a move to shore up its lead
in Alzheimer's diagnostics, Eli Lilly and Co on
Wednesday said it will acquire two imaging agents from Siemens
designed to light up brain deposits of tau, an
Alzheimer's protein linked with cell death.
The two agents are radiopharmaceutical tracers, which are
used with positron emission tomography, or PET scans, to
highlight specific proteins in the brain. Terms of the deal with
the conglomerate's Siemens Medical Solutions USA unit were not
In April 2012, Lilly became the first company to win U.S.
marketing approval for use of its radioactive tracer known as
Amyvid to detect the presence of brain plaques made up of the
protein beta amyloid, an early sign of Alzheimer's disease.
The deal with Siemens follows the announcement last April of
a research collaboration between General Electric Co's GE
Healthcare Medical Diagnostics business and Clino Ltd, a venture
of Japan's Tohoku University, to develop imaging tracers that
can identify the presence of tau proteins in people with
Like the GE deal, the goal of Lilly's acquisition is to
develop imaging agents that speed the development of effective
treatments for Alzheimer's.
Lilly said it plans to use the new technology first in its
Alzheimer's drug research and development programs. The company
also has the option to commercialize the tracers, which are
meant to be used with PET scanners.
There are currently no approved diagnostics that can detect
tau in living patients, which makes research difficult.
Typically detected during an autopsy, tau is known for forming
tangles inside brain cells. The protein is believed to develop
later in the progression of Alzheimer's, when the disease has
begun to kill off brain cells.
Because the presence of tau often signals the advance of
Alzheimer's in the brain, Dan Skovronsky, chief executive of
Avid Radiopharmaceuticals, Lilly's wholly owned subsidiary
focused on molecular imaging, sees the compounds as a potential
way of measuring whether an experimental treatment is working.
"It could answer one of the major unmet needs in Alzheimer's
disease, which is a marker for disease progression and treatment
response," Skovronsky said in an interview.
While amyloid accumulates early in Alzheimer's and then
remains stable, autopsy studies suggest that tau increases as
symptoms get worse, he said.
Skovronsky envisions using tau tangles as a surrogate marker
for disease progression, in much the same way that cholesterol
buildup in the arteries is used as a marker for heart disease.
"It's early and we don't know if that would work or not, but
that is a pretty exciting hope," said Skovronsky, whose team is
charged with validating and developing the tracers.
So far, no drug has been found to prevent the advance of
Alzheimer's, the leading cause of dementia that now affects some
5 million Americans and 38 million people worldwide.
Lilly is developing a number of experimental Alzheimer's
treatments, including solanezumab, which is now being tested in
a number of trials among patients with very early Alzheimer's.