A small study of a treatment that stabilized four Alzheimer's patients for three years is making big waves.

It's not often that a study of a drug being tested in fewer than two dozen people grabs the attention of top experts gathered for a major medical meeting.

But that is what's happening at the Alzheimer's Association International Conference in Vancouver this week. That's where researchers report that for the first time a decades-old drug made from human plasma appears to prevent the decline of memory in people with Alzheimer's disease -- for three years.

The treatment is called Gammagard. It's a form of intravenous immunoglobulin, or IVIG, usually used to treat immune system disorders.

In the typical person with Alzheimer's, you would expect to see memory loss within months, says researcher Norman Relkin, MD, PhD, of Weill Cornell Medical College in New York City. "We saw no memory loss in three years."

Before getting overly excited, note that just four of 21 people studied benefitted to this degree. Only 16 of the 21 even chose to complete the study.

"Still, it's remarkable," says Relkin, who consults for some drugmakers.

"Within a year of starting currently available treatments, you would expect memory and thinking to decline," he says. You would expect patients to start having trouble dressing themselves, for caregivers to feel the burden on them growing. And you would expect to see mood swings and other undesirable changes in behavior, Relkin tells WebMD.

"Yet in these four patients -- all given the same dose of the drug as an infusion twice a month -- scores on tests of all those measures were unchanged at three years," he says.

Relkin says that he is amazed at what some of his patients are able to do. One takes creative writing, another gardens, he says.

Relkin says he is not a rogue cowboy trying to get everyone to try the new treatment. He urges caution and insists that further study is needed.

In fact, Relkin says he would not have even shared his findings with the medical community at this point were it not for the fact that preliminary results of a late-stage phase III trial pitting IVIG against placebo in nearly 400 patients also suggest it is working. The final analysis is due out in the first half of next year.

Other Researchers Are More Cautious

Ron Peterson, MD, director of the Mayo Alzheimer's Disease Research Center in Rochester, Minn., points out that in the past few years alone, several Alzheimer's drugs that made it to this stage failed to pan out in further testing.

"It's tantalizing," he tells WebMD. "But the four patients who did so well were members of a select group that hadn't dropped out because the drug wasn't working or for another reason."

Peterson has worked on IVIG and is also involved in testing other experimental Alzheimer's drugs.

Heather Snyder, PhD, senior associate director of medical and scientific relations at the Alzheimer's Association, is a little more -- albeit still guardedly -- optimistic about Gammagard.

"Yes, these are small numbers, so we have to be very, very cautious," she tells WebMD. "But maintaining mental functioning with no decline in memory for three full years is [unheard of]."
More Than 5 Million Have Alzheimer's

There are more than 5 million Americans living with Alzheimer's disease, which disrupts memory, learning, and other mental functions. By 2010, there will be nearly half a million new cases each year and by 2050, there will be nearly a million new cases annually, according to the Alzheimer's Association.

Researchers believe Gammagard can replenish a depleted pool of natural antibodies against beta-amyloid protein, which forms the sticky plaques that riddle Alzheimer's patients' brains.

Still, even that is not a certain strategy for halting Alzheimer's deadly march, Peterson points out. "It [beta-amyloid] is the leading hypothesis of what causes the disease, but remains unproven."

Because IVIG has been around for years, its side effects in the general population are well known: headaches, rashes, and blood pressure elevations.

"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 two infusions a month. The other new drugs in development are expected to be equally costly.

Although the people in the study had mild to moderate Alzheimer's, the researchers agree that patients with mild disease would benefit the most. "You want to stabilize patients before they have memory loss and other symptoms," Peterson says.

So given Gammagard is already available for other disorders, should people in the earliest stages of Alzheimer's ask their doctors for it?

"Absolutely not!" Relkin says. "You don't make clinical decisions based on a handful of patients. And you could be depriving patients with the disorders for which the drug is approved of lifesaving treatment," he says.

The study was funded by Baxter, which makes Gammagard.

These findings were presented at a medical conference. They should be considered preliminary, as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.