April 14, 2010 (Toronto) -- A decades-old drug made from human plasma
appears to slow the decline of mental skills in people with Alzheimer's
disease, suggest results from a small preliminary study.
The drug is called Gammagard. It's a form of intravenous immunoglobulin, or
IVIG, drugs that are usually used to treat immune system disorders.
Researchers believe the drug can replenish a depleted pool of natural
antibodies against beta-amyloid protein, which forms the sticky plaques that
riddle Alzheimer's patients' brains.
In the new study of 24 patients, scores on a standard test measuring the
disturbances of memory, language, attention, and other cognitive skills that
are hallmark symptoms of Alzheimer's disease dropped an average of slightly
more than five points in those treated with IVIG.
That compares with a 15-point decline in patients who initially received
placebo and switched to IVIG, says Norman Relkin, MD, of Cornell Weill College
of Medicine in New York City.
The IVIG treatment also appeared to slow the rate of brain shrinkage by
about 45%, he tells WebMD.
The findings were presented at the American Academy of Neurology
Relkin says Gammagard produced "benefits like I've never seen before."
He says he had one patient, a former piano player, who played the same four
compositions over and over. "Four to six months into the study, he sight-read a
new piece for the first time in years. Over the next few months, the patient
continued to improve his repertoire," Relkin says.
Since IVIG has been around for years, its side effects in the general
population are well known: headaches, rashes, and blood pressure elevation.
"By and by, it's well tolerated," Relkin says. "But we don't yet know the
side effect profile in an elderly, Alzheimer's disease population."
One thing that is known: The treatment is expensive -- about $2,000 to
$3,000 per treatment. And patients in the study received infusions up to twice
a month, depending on the dose, for 18 months.
In the study, eight patients received a placebo and 16 got one of four doses
of Gammagard every two to four weeks. After 12 weeks, patients in the placebo
group switched over to Gammagard at the same range of doses.
Patients were evaluated every three months using standardized Alzheimer's
tests and MRI scans.
The results are "very encouraging," says Stephen Salloway, MD, a professor
of neurology at Brown University who was not involved with the research.
"To see any signal [that the drug is working] in a study this small is
unexpected," he tells WebMD. "This is the type of response we are hoping
But another researcher urged caution.
"This is a very small phase II study whose purpose is really just to
establish the correct dose," Ron Peterson, MD, director of the Mayo Alzheimer's
Disease Research Center in Rochester, Minn., tells WebMD. "In the past few
years alone, several Alzheimer's drugs that made it to this stage failed to pan
out in further testing."
A larger phase III trial of 360 patients pitting the drug against placebo is
under way, according to Relkin.
The study was funded by Baxter, which makes Gammagard.