New studies say MS drug should go back on market

NEW YORK — A promising multiple-sclerosis drug that was suspended from the market because three people developed a rare brain disease now appears relatively safe and quite effective, three studies found.

The research in today's New England Journal of Medicine comes days before government hearings on whether to allow sales of the drug, Tysabri, to resume.

Tysabri was withdrawn a year ago, only months after it had been approved. The Food and Drug Administration last month agreed to allow testing to resume after its maker said no more cases of the brain disease had emerged.

The new studies found that Tysabri alone or with standard interferon treatment cut the rate of relapse by as much as two-thirds after two years and reduced the number of people whose MS got worse, compared to those on a placebo or interferon alone.

The studies "confirm that this drug is a significant advance for MS treatment," said Dr. Allan Ropper of Boston's Caritas St. Elizabeth's Medical Center, who wrote an editorial in the journal.

Multiple sclerosis is a disease of the central nervous system. There is no cure, and the cause is unknown.

Tysabri was eagerly awaited because it works in a different way than existing drugs, blocking destructive immune cells from entering the brain and damaging nerve tissue.

Patients clamored for the drug when it went on sale, with about 7,000 getting treatment in the first three months.

Then a woman who had gotten Tysabri and interferon for three years in a study died of the brain disease, progressive multifocal leukoencephalopathy (PML), and a second participant contracted it. Sales of the drug were suspended and tests halted.

A participant in a test to see if Tysabri could be used to treat Crohn's disease, a bowel disorder, also died of the brain ailment, which is caused by a common virus that is usually dormant.

An independent committee reported in the journal that a review found no other cases of the brain infection in other study volunteers.