* Baxter treatment now being tested in larger Phase 3 trial
* Results expected early next year
By Julie Steenhuysen
VANCOUVER, July 17 Four Alzheimer's patients
treated with an immune system therapy have seen their disease
stabilize for at least three years, raising hope that the drug
from Baxter International Inc will prove effective in
Scientists say the study released on Tuesday is too small to
show whether the drug will ultimately prove effective, but any
sign of progress in Alzheimer's research is welcome. Scientists
expect Baxter's results next year.
"Over the last few years there have been a lot of
conspicuous failures with Alzheimer's drugs," said Dr. Norman
Relkin of Weill Cornell Medical College in New York. Relkin
presented three-year results on Baxter's study at the
Alzheimer's Association International Conference in Vancouver.
Most Alzheimer's patients typically decline over three to
six months, so to have the disease stabilize in four patients
-all treated for three years with the same dose of the same drug
- is "a very unexpected and very positive finding," he said.
There are no licensed drugs that can slow the progression of
Alzheimer's, and currently approved medications only treat
symptoms. The disease is the most common form of dementia,
affecting 5.1 million Americans and 35 million people globally.
Relkin presented three-year data on 16 patients in Baxter's
Phase 2 study of Gammagard, which originally enrolled 24
Overall, all 11 study participants who got Gammagard for the
full three years showed improvements in thinking abilities,
behavior and daily functioning.
Of these, the four patients who received the most effective
dose (0.4g/kg) for the full 36 months fared the best, showing no
decline on several standard measures of cognition, memory, daily
functioning and mood.
Many drugs fail despite very encouraging Phase 2 results,
Relkin said. The real proof of Gammagard's effectiveness will
come early next year with the release of results of the
large-scale, Phase 3 study, which he is also leading.
Experts predict that without an effective treatment, the
number of Americans with Alzheimer's will double by 2050 to more
than 10 million, and related healthcare costs could soar above
$1 trillion a year.
Other Alzheimer's treatments in late-stage clinical trials -
Johnson & Johnson and Pfizer Inc's bapineuzumab
and Eli Lilly's solanezumab - use powerful, manmade
antibodies to target a protein called beta amyloid that
accumulates in the brains of patients with Alzheimer's disease.
Late-stage studies of bapineuzumab and solanezumab are
expected within the next few months.
Gammagard is different from them. The drug is an intravenous
immune system treatment made from natural antibodies taken from
young, healthy blood donors. Known generically as intravenous
immunoglobulin, or IVIG, the therapy is typically used to fight
infections in patients with weakened immune systems.
Compared with solanezumab and bapineuzumab, which Relkin
describes as "industrial-strength vacuum cleaners" used to
remove beta amyloid from the brain, he says IVIG's natural
antibodies are more like "gentle, whisk brooms."
"It may be that a gentler approach is a more realistic
approach in the long run," he said.
Dr. Sterling Williams, an obstetrician/gynecologist from
Silver Spring, Maryland, has watched the drug at work. His wife
Joice, 71, is one of the four patients who has benefited from
Gammagard and is completing her sixth year on the treatment.
"There has been some decline, but it has been very slow, and
she is still relatively independent in functioning at home and
in her activities of daily living," said Williams, who is also
71. "Every morning, she gets up, fixes breakfast, washes
clothes, irons -- all of that is fine."
She becomes a bit confused in a new environment, such as a
hotel, Williams said.
Some of the other study patients also still function
independently. "They travel by themselves," Relkin said. "They
take part in community activities. They volunteer."
Over time there have been declines, he said, but these have
been consistent with normal aging.
Dr. Ralph Nixon, an Alzheimer's researcher at New York
University Langone Medical Center, said the finding was
encouraging because it is taking place in a population of
patients who were already affected by the disease.
"It's one of the first trials to really show some signs of
therapeutic benefit in an affected population," something he
described as a "very meaningful and hopeful sign."
Dr. Laurie Ryan, program director for Alzheimer's disease
clinical trials at the National Institute of Aging, one of the
National Institutes of Health, said the study's findings
suggested the treatment should be tested further.
If Gammagard does prove effective in the larger trial,
supply and cost may limit its use.
Each dose contains pooled antibodies from the plasma of
1,000 blood donors. Typically, each of the two treatments a
month that patients need costs between $1,500 and $3,000,
depending on a person's weight.
If the drug works, the challenge will be determining which
of the antibodies are actually helping patients and developing a
product that is easier and cheaper to make, Relkin said.