MS vaccine shows promise

Monday August 13 2007

A DNA vaccine for multiple sclerosis has passed its first safety tests in humans, and has shown some promising indications that it may be beneficial, a small preliminary trial has found. This story was reported in multiple news sources including The Daily Telegraph , The Guardian and the BBC.

The vaccine is intended to treat people who already have multiple sclerosis (MS). MS is a disease where the body’s immune system damages the central nervous system resulting in a host of debilitating problems including weakness, numbness, and vision, speech, and coordination difficulties.

Previous trials in animals have suggested, “It might be possible to tweak the body's immune system so that the unwanted self-harming response becomes smaller, slowing the progress of the disease”, the BBC reported.

The Guardian quoted the study’s authors: "We have demonstrated in this first, to our knowledge, in-human trial of a DNA vaccine for auto-immune disease that the approach is safe and well tolerated."

Both sources also reported that the authors of the study urge caution and that larger and longer term trials will be needed to examine the potential benefits of this vaccine for people with MS.

The original research was a small, randomised controlled trial looking at the safety of the BHT-3009 DNA vaccine. Our assessment is that the results of this study seem reliable but are preliminary, particularly in terms of seeing what benefits the vaccine might have. A larger trial is currently being conducted to test the benefits of the vaccine and also further test for possible safety issues.

Where did the story come from?

This study was carried out by Doctors Bar-Or, Garren, and colleagues at universities, neurological research units and Bayhill Therapeutics, Inc. in Canada and the US. The study was funded by Bayhill Therapeutics, Inc.  The study was published in the peer-reviewed journal Archives of Neurology .

What kind of scientific study was this?

This was a small, early-stage randomised controlled trial (definition) which aimed to look at the safety of the BHT-3009 DNA vaccine for the treatment of multiple sclerosis (MS).

Researchers enrolled 30 adults with relapsing-remitting MS, where periods of recovery of normal function are interspersed with periods of symptomatic disease (this form of MS often occurs when the disease is first diagnosed) or secondary progressive MS, where there is incomplete recovery of function in between periods of symptomatic disease (this often develops gradually from the relapsing-remitting form).

The participants were randomly allocated to receive the vaccine alone, or vaccine plus a statin drug (atorvastatin), or placebo. The vaccine was given in three different doses to see which one worked the best. Four vaccine injections were given in total, over a period of nine weeks. All participants were followed for 13 weeks and monitored for safety outcomes, changes in their immune systems, symptoms of relapse and disability, and changes in their brains measured by magnetic resonance imaging (MRI).

Participants and researchers were blinded (definition) as to which treatment was being received.

What were the results of the study?

The proportion of people who experienced side effects in the vaccine group was no higher than the proportion experiencing side effects in the placebo group. All the side effects seen were judged to be short-lived, and of only mild to moderate severity.

The addition of a statin drug to the vaccine did not appear to add any benefit to the vaccine alone. Participants receiving the vaccine did not show any worsening of brain lesions (areas of active disease that are enhanced by a chemical given during the brain imaging scan), and instead showed some improvements in brain lesion number and size compared to placebo, although these differences were not large enough to be statistically significant.

What interpretations did the researchers draw from these results?

The researchers concluded that the BHT-3009 DNA vaccine was safe for use in people with MS, and showed promising reductions in brain lesions.

What does the NHS Knowledge Service make of this study?

This was a good quality study assessing the safety of the BHT-3009 DNA vaccine. However, the results should be considered preliminary because of its small size.

Although initial results showing a trend towards reduction in brain lesion size are promising, the results of a larger randomised controlled trial are needed to assess whether the vaccine can produce significant benefits for people with MS. Such a trial has been started and is currently ongoing. In addition, this larger trial should also provide further information about safety.

Analysis by Bazian
Edited by NHS Choices