FDA OKs Multiple Sclerosis Drug

Tuesday, October 17th 2000, 12:00 am
By: News On 6

WASHINGTON (AP) — The government gave its approval Friday for doctors to use a cancer drug as the first treatment for people with crippling late-stage multiple sclerosis.

An estimated 350,000 Americans suffer from MS, a disease that attacks the nervous system to cause weakness, blurred vision, poor muscle coordination and sometimes paralysis.

The Food and Drug Administration approved mitoxantrone — to be sold under the name Novantrone — for patients with the secondary progressive form of the disease. In these patients, the drug reduced the frequency of flare-ups and slowed the progression of disability.

The FDA warned, however, that some patients using the drug can develop serious heart problems, a risk that increases with the cumulative dose.

Patients should receive no more than eight to 12 doses of the drug, spread over two to three years, the agency said.

That means using Novantrone safely will require patient and doctor education to make sure its use is stopped after the dose limit is reached.

Nonetheless, an FDA advisory committee recommended approval of the drug for MS last January. Novantrone is already approved for treatment of certain types of prostate cancer and leukemia.

MS starts with such symptoms as numbness, tingling and fatigue but progresses to difficulty walking and seeing and eventually, in some patients, paralysis.

It usually strikes people aged 20 to 40 and tends to occur in sporadic attacks, or flares. Some patients have periods of severe symptoms, after which they recover almost totally until the next attack. Others have the worse ``secondary progressive'' form, where the flares become more and more frequent, and they cannot recover from damage each flare causes.

Three drugs are in use that can somewhat ease relapsing-remitting MS, but until now no drug has been proved to work against the more severe form.

MS occurs when patients' immune systems attack the fatty layer of insulation, called myelin, that protects nerve fibers in the brain and spine.

Novantrone, marketed by Seattle-based Immunex Corp., works against MS by suppressing the attacking immune cells.

In a two-year study of 194 Europeans with advanced MS, high doses of the drug slowed the disease's progression by 65 percent.

Novantrone causes other side effects typical of cancer chemotherapy — some nausea, hair loss, menstrual disorders, certain infections. But the main shortcoming is the potential heart damage.

Novantrone is given intravenously once every three months, costing $2,800 to $3,000 for a year's treatment.