TRENTON, N.J. -- For Alzheimer's patients and their families,
desperate for an effective treatment for the epidemic disease, there's
hope from new studies starting up and insights from recent ones that
didn't quite pan out.
If the new studies succeed, a medicine that
slows or even stops progression of the brain-destroying disease might be
ready in three to five years, said William H. Thies, chief medical
officer of the Alzheimer's Association. The group assists patients and caregivers, lobbies for more research and helps fund studies.
"The
number of smart people working on this problem means to me we'll begin
to manage it better in the very near future," Thies said. "It may be as
short as three years away."
That's only if government and other
sources provide tens of millions of dollars for additional research and
more patients join clinical studies.
After decades of stumbles and
dozens of promising experimental drugs failing, scientists think
they're now on the right track. They're targeting what they believe are
the mechanisms to arrest a disease that steadily steals patients'
personality and ability to remember, think and care for themselves.
A
vaccine is in mid-stage testing, and drugmakers shy about funding
expensive treatment tests could start as many as 30 studies once they're
more confident that their approach is sound, Thies said. Early next
year, the first study to try to prevent Alzheimer's begins - in people a
decade away from symptoms but who have a genetic mutation that causes
early onset Alzheimer's. It will include three drugs that each attack
the country's No. 6 killer in a different way.
And in May, the
Obama administration unveiled an ambitious national plan to fund new
research, better train those caring for Alzheimer's patients and help
families get needed services via a new website.
The
number of Alzheimer's patients in the U.S. is expected to jump from the
current 5.4 million to 16 million by 2050. Costs for care, mostly borne
by taxpayers, could skyrocket from roughly $200 billion this year to
$1.1 trillion in 2050. The few treatments available only ease symptoms
temporarily.
On Monday, drugmaker Merck & Co. announced it's just begun the first combined mid- and late-stage study
of a BACE inhibitor. That's a new type of drug designed to slow mental
and functional decline by limiting production of amyloid beta, the
protein that's the main ingredient in brain-damaging amyloid plaques
considered the most likely cause of Alzheimer's.
After safety
testing of the drug MK-8931 in about 200 patients, the 78-week study,
known by the acronym EPOCH, will quickly expand to as many as 1,700
patients. That phase will test the daily pill at three different doses,
compared with a dummy pill.
Combining study phases should shave
some time from the years-long, and often billion-dollar, research
process. If MK-8931 works, EPOCH would give Merck one of the two major
patient studies needed to win approval from government regulators, said
Darryle D. Schoepp, Merck's head of neuroscience research. Merck also
has some backup compounds and plans other studies, including some on
patients very early in the disease, Schoepp told the Associated Press in
an exclusive interview.
In earlier research MK-8931 blocked formation of almost all the toxic amyloid plaques, he said.
"No one's ever done that before," Schoepp said. "If (amyloid) plaques are the cause, the medicine will work."
Merck's
MK-8931 and some other experimental drugs aim to turn off the
Alzheimer's "faucet" by blocking production of amyloid beta. Other
experimental drugs instead aim to bail out the sink while the faucet's
still running, either by removing clumps of amyloid plaque from the
brain or by binding to bits of amyloid beta protein and clearing them
from the brain before they clump into plaques.
Researchers were
frustrated this year by failures of two drugs that targeted amyloid beta
- bapineuzumab from Pfizer Inc. and Johnson & Johnson, and
solanezumab from Eli Lilly and Co. Both drugs are injected because their
large molecules can't pass through the digestive tract into blood
vessels. Their size might have limited how much medicine could get
inside brain cells.
However, solanezumab showed signs that
attacking beta amyloid beta was effective. While it didn't help most
patients in the study, it slowed mental decline by about a third in
patients with mild forms of the disease - a first for that approach.
That's
added to researchers' growing belief that patients must be treated
early on, before Alzheimer's has destroyed much of their brains.
The
big prevention study to start early next year, called DIAN TU, is meant
to help find a way to do that, by testing drugs on people with a family
history and genes that make them likely to develop Alzheimer's in their
50s, rather than after 65.
- One part will test the
Roche Group's biologic antibody drug gantenerumab, which removes amyloid
beta plaques from the brain. It's already in late-stage testing in
patients who don't have symptoms but have abnormally high levels of
amyloid beta in spinal fluid.
- Another part will test Lilly's
solanezumab, which binds to smaller bits of amyloid beta and clears them
from the brain before they clump into plaques.
- The third study
drug could be Lilly's BACE inhibitor, now in midstage testing in
Alzheimer's patients. The company expects by mid-2013 to complete work
needed to determine whether the drug is right for the prevention study.
Meanwhile,
two late-stage patient studies started this fall with a drug called
LMTX developed by TauRx Pharmaceuticals Ltd. It targets tangles in the
brain with an abnormal version of a protein called tau.
Thies, of
the Alzheimer's Association, thinks the disease likely is caused by a
combination of those tau tangles and amyloid beta plaques.
The key issue for all these drugs will be what side effects they cause, because patients would take them for many years.
Patients and families are anxious for a drug that slows or stops Alzheimer's.
"When
you're faced with a diagnosis that tells you your brain is being eaten
up," said patient Ron Grant, "and you start seeing who you were no
longer being who you are, and the only thing you can expect is being
worse, in this day that's totally unacceptable."
The Oklahoma City
prison chaplain was diagnosed with Alzheimer's in 2007 at age 55 and
had to stop work barely a year later. He's helped found a support group
for early onset Alzheimer's patients, participated in a clinical trial
and takes the drugs Namenda and Razadyne, which he thinks have limited
his symptoms.
But PET scans of his brain show the disease is
progressing. The former avid reader can no longer follow a book's plot
or remember where he left off.
The federal government doesn't spend enough on Alzheimer's, said Grant, who helps lobby Congress for more funding.
"The biggest thing standing between us and a treatment for this disease is money," he said.
Associated Press