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Vaccines Show Promise Fighting Parkinson's, Other Brain Diseases
- Jun 15 2004
To treat some of the most debilitating and feared illnesses of the brain, researchers are turning to some of the oldest weapons in medicine: vaccines.
Vaccines typically use the body's natural defenses to prevent diseases such as smallpox and polio. Now, a vaccine approach that may be able to slow the progression of diseases such as Parkinson's, Alzheimer's and Huntington's has shown promising results.
In a four-year study published yesterday in the journal Proceedings of the National Academy of Sciences, a vaccine given to mice with Parkinson's protected about half of the nerve cells that would normally be killed by the disease.
The experimental vaccine marks an "exciting conceptual advance" for Parkinson's and other brain disease therapy, says Howard Gendelman, director of the Center for Neurovirology and Neurodegenerative Disorders at Nebraska, where the research was conducted. But he cautioned that until human studies of the vaccine are completed, "we won't know if what works in mice will work in humans."
Other vaccines that could be used to treat brain diseases have also shown promising results in animals, and some are now being tested in humans. These vaccines, unlike those used to keep children safe from infections, wouldn't be preventative but rather would slow the diseases' advance.
The experiments are risky, and success is uncertain. One trial of a vaccine for treating Alzheimer's was cut short two years ago because it caused brain inflammation in about a dozen of the 300-plus patients receiving the drug.
But if researchers can find a way around the obstacles, the new approach could open a whole menu of treatments for some of humankind's most dreaded diseases, which rob people of the ability to function in society, move and even think. Researchers are also studying their effectiveness against addictions to nicotine and cocaine.
Such drugs could "significantly increase quality time" in patients suffering from these diseases, says Harris Gelbard, professor of neurology at the University of Rochester in upstate New York, and a specialist in neurodegenerative diseases. He isn't affiliated with any of the trials of brain vaccines.
The trials are still small in size and often have strict criteria for inclusion. But people who are interested in taking part can call the companies or institutions leading the studies. They will likely stand a better chance of taking part in the next, larger stage of testing, known as Phrase 3 trials. (For a look at some of the vaccines being used in trials, see page D4.)
In one of the trials, Wyeth, a large U.S. drug maker, has teamed up with Irish pharmaceuticals company Elan Corp. to test vaccines against Alzheimer's in humans. The companies hope their vaccine will induce the body to produce antibodies to winnow clumps of proteins in the brain that may be responsible for the symptoms of the mind-robbing dementia. Their vaccine is an improved version of the one discontinued for harming patients two years ago.
In the latest effort at developing brain vaccines, researchers at the University of Nebraska and Columbia University in New York reported success in protecting mice from much of the devastation of Parkinson's, which leads patients to lose control of their muscles.
The same vaccine is also part of a six-month study on 30 patients with Lou Gehrig's, or amyotropic lateral sclerosis, a degenerative nerve disease, that is under way at Columbia. Results are expected a year from now. Larger-scale studies of the vaccine on both Lou Gehrig's and Parkinson's patients are planned for next year. Between 500,000 and 1.5 million Americans have Parkinson's disease and 50,000 new cases are reported each year.
The disease attacks the nerve cells in the brain that produce dopamine. The death of those cells results in uncontrollable shaking, slow movement, rigid limbs and a stooped posture.
Current treatments for Parkinson's seek to relieve its chief symptom -- the decline in muscle control. The new vaccine uses a drug called Copaxone or Cop-1, which is similar to a protein found in the brain. The drug, approved by the Food and Drug Administration, is used to treat multiple sclerosis.
The vaccine essentially helps complete the immune process that brain diseases cut short. After most injuries, the body's immune cells go to protect the affected area, causing inflammation. Soon after, the body dispatches other immune cells to reduce the inflammation and heal the wound.
But with Parkinson's disease and other brain-related disorders, researchers believe, cells that turn off the inflammation are impeded from entering the brain by its blood barrier. This puts more stress on the surviving nerve cells, which accelerates the disease, Dr. Gendelman says.
The vaccine helped turn off the inflammation in mice and also strengthened the natural repair of damaged cells, he says.
The study was funded in part by foundations and the National Institutes of Neurological Disorders and Stroke and the U.S. Department of Defense.
A New Approach: The following vaccines for treating brain ailments are being studied in humans. Some of the treatments could still be years away.
AILMENT: Alzheimer's VACCINE: ACC-001 SPONSOR: Wyeth; Elan
AILMENT: Cocaine addiction VACCINE: TA-CD SPONSOR: Xenova Group
AILMENT: Nicotine addiction VACCINE: NicVax SPONSOR: Nabi Biopharmaceuticals
AILMENT: Nicotine addiction VACCINE: TA-NIC SPONSOR: Xenova Group
AILMENT: Parkinson's, Lou Gehrig's, other brain diseases VACCINE: Copaxone
SPONSOR: National Institutes of Health (study done at Columbia Univ.)
Source: Wall Street Journal Author: Amir Efrati
Source Date: Jun 15 2004
Source Publication: Wall Street Journal