January 29, 2000
By SHERYL GAY STOLBERG
GAITHERSBURG, Md., Jan. 28 -- A cancer chemotherapy drug is the first effective treatment for certain forms of advanced multiple sclerosis and should be approved for that use, according to a unanimous recommendation today by a panel of scientific experts to the Food and Drug Administration.
If the agency follows the panel's recommendation, as is expected, the drug, mitoxantrone, would become the first approved treatment that can slow the rate of neurological disability and reduce flare-ups in patients whose multiple sclerosis is rapidly worsening. More than 100,000 patients could benefit.
"This opens up a new era in the treatment of multiple sclerosis," said Dr. Howard L. Weiner, a neurologist at Brigham & Women's Hospital in Boston who served as a consultant to the committee. Although doctors are already using chemotherapy drugs for multiple sclerosis, he said, having government approval will legitimize the practice and lead to more widespread use.
But mitoxantrone, which goes by the brand name Novantrone and was first approved in this country for treatment of leukemia in 1987, has drawbacks. It is not a cure, and it will not reverse damage.
And Novantrone has a serious side effect, heart damage, which means that patients will be able to take it for no longer than two or three years.
"It will have to be monitored carefully," said Dr. Stephen Reingold, vice president for research at the National Multiple Sclerosis Society. "It is not going to be able to used lightly or for very long, but the consensus is it does have a role in slowing neurologic disability. So that's good news for people who are not otherwise being treated."
According to the manufacturer, Immunex Corporation of Seattle, the drug, which is administered as an intravenous infusion, will cost patients about $3,000 a year.
An estimated 350,000 Americans suffer from multiple sclerosis, a crippling, and often unpredictable, immune system disease that causes a breakdown of the myelin sheath, the protective insulation that surrounds the nerve fibers of the central nervous system. Its symptoms vary in severity from patient to patient, but they include excessive weakness, impaired vision, loss of balance and muscle coordination, loss of cognitive ability and, in the most severe cases, paralysis.
In its early stage, the disease typically takes a course of remissions and relapses, in which patients experience periodic flare-ups, or relapses, and then recover. This is known as "relapsing remitting" multiple sclerosis, and about 70 percent of all M.S. patients are placed in this category at the time of diagnosis. There are already three drugs on the market to treat this form of the disease.
After about 10 years, however, half of these patients go on to develop "secondary progressive" multiple sclerosis, in which patients gradually worsen between flare-ups. Novantrone would be used for them, as well as patients with relapsing remitting multiple sclerosis that is worsening more rapidly than usual.
Patients are eager to have the new drug. Among three who testified today was Mary Elizabeth McNary, 39, of Washington, who gave birth to twins five months ago. Her gait is slow, and double vision prevents her from driving. She said she received a diagnosis of relapsing remitting M.S. in 1990, and is now wondering if her condition will worsen.
"My M.S. has been relatively merciful to me; nonetheless, I feel that I am under the sword of Damocles," Ms. McNary said. "It's really frightening now that I'm a mother, to think that I might not be able to hold my babies."
With the advisory committee's recommendation, Dr. Robert Temple, an F.D.A. official, said the agency will move quickly to make the drug available to patients. Formal approval could come within a matter of weeks, he said.
The panel's 7-0 vote came after a day of intense discussion over the validity of the scientific data presented by Immunex. In a study of 194 patients in four European countries, the company found that the annual rate of relapse was 21 percent for patients on the maximum Novantrone dose, while the relapse rate in a group receiving a fake treatment, or placebo, was 60 percent.
Although the findings were compelling, the study troubled committee
members because it was partially "unblinded," meaning that the patients'
doctors knew which treatments they were taking, although the scientists
analyzing the data did not.