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Alzheimer's treatment on horizon

An expensive new treatment may help remove errant proteins in the brain. An expensive new treatment may help remove errant proteins in the brain.

By TOM VALEO
Published November 7, 2006

An experimental treatment that could cost up to $10,000 a month has shown strong promise in treating Alzheimer's patients in a limited study. But patients who could manage to get this experimental treatment might be taking the medication from someone else who needs it for lymphocytic leukemia, myasthenia gravis or one of the other maladies that yield to the power of this precious substance.

The substance is called intravenous immunoglobulin, or IVIg, and it has been used for more than 30 years to treat a variety of immune system problems.

While effective, it remains extraordinarily expensive because each dose contains antibodies painstakingly distilled from the blood of thousands of donors. These are not the antibodies that people develop against bacteria and flu viruses. Rather, they come from the basic set of antibodies that circulate in every human's bloodstream from birth, and they sound the alarm at the first sign of an invader.

In Alzheimer's disease, proteins produced in the brain throughout life suddenly start to fold improperly, which causes these antibodies to identify them as invaders. These misfolded proteins clump together into the amyloid plaques that are one of the hallmarks of Alzheimer's.

As the immune system attacks these misfolded proteins, they trigger inflammation that certainly aggravates Alzheimer's and may even be an underlying cause of the disease.

IVIg seems to supply reinforcements that help immune cells carry these misfolded proteins out of the brain. A pilot study involving just seven Alzheimer patients produced such impressive results that the National Institute on Aging is organizing a larger study.

What if it works? Producing IVIg is such a costly, laborious process that producing enough for the 4.5-million people who have Alzheimer's would be impossible.

Although approved for only a small number of illnesses, physicians may prescribe IVIg for any purpose they deem appropriate, including Alzheimer's.

Explained Norman P. Relkin, who is conducting the trial for the NIA: "It is within a physician's prerogative to prescribe it, but . . . we're talking about a very expensive product that is in limited supply."

Still, initial studies suggest that IVIg works better than anything developed so far. But unlike a vaccine, which stimulates the body to produce a specific antibody against a single, specific target that may be the cause of the disease, IVIg deploys a variety of antibodies against a broad range of suspicious proteins.

If IVIg helps patients get better, the challenge will be to figure out which antibody deserves the credit, and what, exactly, it attacked. That means that vast amounts of IVIg won't be necessary to treat Alzheimer's. Instead, only those antibodies that actually do the work will be cultivated, which will make the treatment much less expensive.

Relkin, a neurologist at the Weill Medical College of Cornell University, thinks something must be done quickly.

"There's an epidemic of Alzheimer's on the way as baby boomers age, and there's a 10- to 12-year development time for new pharmaceuticals," he said. "We view this as an interim solution on the path to something better."

Freelancer Tom Valeo writes about medical and health issues. Write to him in care of Pulse, St. Petersburg Times, P.O. Box 1121, St. Petersburg, FL 33731, or e-mail features@sptimes.com.

An experimental treatment that could cost up to $10,000 a month has shown strong promise in treating Alzheimer's patients in a limited study. But patients who could manage to get this experimental treatment might be taking the medication from someone else who needs it for lymphocytic leukemia, myasthenia gravis or one of the other maladies that yield to the power of this precious substance.

The substance is called intravenous immunoglobulin, or IVIg, and it has been used for more than 30 years to treat a variety of immune system problems.

While effective, it remains extraordinarily expensive because each dose contains antibodies painstakingly distilled from the blood of thousands of donors. These are not the antibodies that people develop against bacteria and flu viruses. Rather, they come from the basic set of antibodies that circulate in every human's bloodstream from birth, and they sound the alarm at the first sign of an invader.

In Alzheimer's disease, proteins produced in the brain throughout life suddenly start to fold improperly, which causes these antibodies to identify them as invaders. These misfolded proteins clump together into the amyloid plaques that are one of the hallmarks of Alzheimer's.

As the immune system attacks these misfolded proteins, they trigger inflammation that certainly aggravates Alzheimer's and may even be an underlying cause of the disease.

IVIg seems to supply reinforcements that help immune cells carry these misfolded proteins out of the brain. A pilot study involving just seven Alzheimer patients produced such impressive results that the National Institute on Aging is organizing a larger study.

What if it works? Producing IVIg is such a costly, laborious process that producing enough for the 4.5-million people who have Alzheimer's would be impossible.

Although approved for only a small number of illnesses, physicians may prescribe IVIg for any purpose they deem appropriate, including Alzheimer's.

Explained Norman P. Relkin, who is conducting the trial for the NIA: "It is within a physician's prerogative to prescribe it, but . . . we're talking about a very expensive product that is in limited supply."

Still, initial studies suggest that IVIg works better than anything developed so far. But unlike a vaccine, which stimulates the body to produce a specific antibody against a single, specific target that may be the cause of the disease, IVIg deploys a variety of antibodies against a broad range of suspicious proteins.

If IVIg helps patients get better, the challenge will be to figure out which antibody deserves the credit, and what, exactly, it attacked. That means that vast amounts of IVIg won't be necessary to treat Alzheimer's. Instead, only those antibodies that actually do the work will be cultivated, which will make the treatment much less expensive.

Relkin, a neurologist at the Weill Medical College of Cornell University, thinks something must be done quickly.

"There's an epidemic of Alzheimer's on the way (as baby boomers age), and there's a 10- to 12-year development time for new pharmaceuticals," he said. "We view this as an interim solution on the path to something better."

Freelancer Tom Valeo writes about medical and health issues. Write to him in care of Pulse, St. Petersburg Times, P.O. Box 1121, St. Petersburg, FL 33731, or e-mail features@sptimes.com.

[Last modified November 7, 2006, 06:22:02]