Experimental MS Vaccine Proves Safe in Early Test

It could lead to individualized treatments for other autoimmune diseases, researchers say.

By Steven Reinberg
HealthDay Reporter
Monday, August 13, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

MONDAY, Aug. 13 (HealthDay News) -- An experimental DNA vaccine to fight multiple sclerosis is safe and may also be effective, results of a small Canadian trial suggest.

The vaccine, called BHT-3009, works by preventing the immune system from attacking the myelin sheaths that protect nerve cells in the brain and spinal cord. The destruction of myelin eventually destroys a nerve cell's axon, which prevents cells from transmitting messages and is one of the hallmarks of MS.

"This was an early trial of a new class of drugs for autoimmune disease in general and for MS in particular," said lead researcher Dr. Amit Bar-Or, of McGill University's Montreal Neurological Institute.

The idea of the vaccine is to change the immune cells that target the nervous system, Bar-Or said. "What we want to do is focus on just those cells that are involved in the disease process," he said. "So antigen-specific therapies are designed to try to modify or eliminate only those bad-guy cells that are involved in the disease process."

The vaccine makes use of a backbone of DNA onto which is attached myelin basic protein, which is a component of myelin. When you inject it, the vaccine reduces the body's ability to attack myelin, Bar-Or explained.

The findings were published online Monday in Archives of Neurology and were expected to be published in the October print issue of the journal.

According to the National Multiple Sclerosis Society, the disease's symptoms are unpredictable and vary from person to person, and even from time to time in the same person. One person may experience abnormal fatigue, while another might have severe vision problems. A person with MS could have loss of balance and muscle coordination, making walking difficult. Another person could have slurred speech, tremors, stiffness and bladder problems.

In the new study, Bar-Or and his colleagues gave the vaccine to 30 patients with relapsing-remitting MS, which is characterized by alternating periods of symptoms and then relief from those symptoms. At one, three, five and nine weeks, the study participants received injections of BHT-3009 or a placebo. After 13 weeks, those who had been given a placebo were given four injections of BHT-3009.