Cancer Drug Gets FDA OK for MS Treatment
Oct. 13, 2000 -- The FDA approved a dual role for cancer drug mitoxantrone Friday, permitting its maker, Immunex, to market it as a treatment for worsening multiple sclerosis (MS).
Mitoxantrone, which will be sold under the name Novantrone for MS, has already been approved to treat pain in patients with advanced forms of prostate cancer. And it's used with other drugs in the initial therapy of acute nonlymphocytic leukemia.
But the FDA said Friday that the drug was found to reduce the number of relapse episodes and decrease the progression of disability in MS patients who have chronic, progressive-relapsing, or worsening relapsing-remitting forms of the disease.
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.
In a two-year study of 194 Europeans with advanced MS, high doses of the drug slowed the disease's progression by 65%.
The FDA noted the drug was not tested in patients who have a form of MS that causes the nervous system to deteriorate over time without specific relapses, a form called primary progressive MS.
An estimated 350,000 Americans suffer from MS, which occurs when patients' immune systems attack the fatty layer of myelin that protects nerve fibers in the brain and spine. The nerve damage usually leads to weakness, blurred vision, poor muscle coordination, and sometimes paralysis.
It is believed that Novantrone can suppress the attacking immune cells behind MS.
Tim Warner, director of corporate communications for Immunex, tells WebMD that there are about 140,000 MS patients in this country who would be appropriate candidates for Novantrone.
These patients, he says, have worsening forms of the disease, where their condition is leading to disability or already has caused it. Other treatments may have failed or the patients may not be satisfied with the results they are getting from their present treatment.
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 federal regulators said.
That means using the drug safely will require patient and doctor education to make sure its use is stopped after the dose limit is reached.
Warner adds that MS patients interested in this therapy need to work very closely with their neurologist to see if the drug is right for them.
Susan Cruzan, spokeswoman for the FDA, tells WebMD that doctors who put their MS patients on this drug need to keep watching heart output, and patients should receive routine echocardiograms.
Cruzan says doctors need to get baseline tests and order new ones as the drug is being administered either by injection or IV, in order to stay on top of the possible heart and blood side effects that can occur.
She adds that some of Novantrone's side effects stem from its activities as a cancer drug, so doctors need to watch the patient's white blood cell count.
Novantrone causes other side effects typical of cancer chemotherapy -- some nausea, hair loss, menstrual disorders, and certain infections. But the main shortcoming is the potential heart damage.
Nonetheless, Friday's FDA approval for Novantrone in MS patients follows the administration's advisory committee's recommendation to give the OK last January.
The drug is given once every three months, costing $2,800 to $3,000 for a year's treatment.