Vaccine could stop MS in its tracks

THE immune cells that attack the brains and nerves of people with multiple sclerosis could be turned into a weapon against the disease.

This month sees the beginning of a trial of a personalised vaccine for MS, designed to rein in and destroy the renegade white blood cells that attack myelin cells lining the brain and nerves of patients.

To make the vaccine, PharmaFrontiers of Woodlands, Texas, takes blood from an MS patient and extracts a sample of these renegade cells. The cells are then multiplied and weakened with radiation before being re-injected into the patient, whose immune system will then recognise them as damaged and attack them, sometimes wiping them out completely, according to the results of earlier trials. The immune system will also attack healthy renegade cells, which have the same markers on their surface. In one trial of 15 people with MS the rate of new flare-ups was reduced by 92 per cent.

If this success is repeated in the new trial it might mean that regular shots could slow or even arrest progression of the disease. "If that's the case, the earlier we can do it after diagnosis the better," says David McWilliams of PharmaFrontiers. In the current trial, 100 patients will receive the treatment and 50 a dummy treatment. The vaccine would only need to be injected four times a year, while other MS drugs need to be given on a weekly or daily basis.

However, since all previous attempts to develop a vaccine for MS have failed, Richard Rudick of the Mellen Center for Multiple Sclerosis Treatment and Research in Cleveland, Ohio, is cautious about its prospects. "None have worked so far. This one may, but we don't yet know."

In the meantime, good news may await MS patients in the US. This week the US Food and Drug Administration is expected to lift its ban on prescribing Tysabri following new evidence on its safety and effectiveness. Tysabri, which is twice as effective at quelling symptoms as any other MS drug available, was pulled a year ago after three people taking it died from rare brain infections.

The superiority of Tysabri over existing, beta-interferon treatments was shown by three separate studies published in The New England Journal of Medicine last week (vol 354, p 899, p 911 and p 924). "With interferons, we've normally seen roughly a one-third reduction in the relapse rate," says Rudick, who led one of the studies. "With Tysabri, we saw more than a two-thirds reduction."

From issue 2542 of New Scientist magazine, 09 March 2006, page 12

Submitted  3/10/2006 12:37:54 AM