WEDNESDAY, Sept. 22 (HealthDay News) -- The U.S. Food and Drug Administration on Wednesday approved the first oral drug to reduce relapses of multiple sclerosis, the nervous system disorder that has traditionally been treated with injectable drugs.

Gilenya (fingolimod) is designed to reduce relapses and delay the progression of debilitating symptoms in patients with relapsing forms of multiple sclerosis (MS). The drug, which works by altering the immune system response, will be available in capsule form.

Research published in January in the New England Journal of Medicine found that Gilenya reduced relapse rates in people with relapsing-remitting multiple sclerosis. However, as is often the case with immune-suppressing medications, there were concerns about side effects, including an increased risk of serious infections and, possibly, cancer.

"Oral drugs are what people with MS have been wishing for a long time. This is wonderful news for people with MS," Dr. John Richert, former executive vice president of research and clinical programs for the National Multiple Sclerosis Society, told HealthDay at the time the research was published. The drug appears to be "quite effective," and at the moment, appears to have a reasonable risk-benefit ratio. "However," he added, "it will be very important for people with MS and their physicians to remain vigilant and be on the lookout for side effects."

The January research was funded by the drug's manufacturer, the Swiss pharmaceutical company Novartis.

Multiple sclerosis is a chronic, potentially disabling illness that's believed to be an autoimmune disorder. In MS, the body's natural defense system mistakenly attacks the fatty substance that protects the nerves (myelin) in the brain and spinal cord. About 400,000 Americans have multiple sclerosis, which is characterized by periods of well-being followed by periodic relapses, according to the multiple sclerosis society.

Until now, the existing treatments for reducing relapses in relapsing MS were all injectable medications, which Richert said is sometimes a barrier for people to start early treatment. He said that treatments may be more successful if they're started early in the course of the disease, so he's hoping that having oral medications will help people start treatment sooner.

The two Gilenya studies published in January were phase 3 studies. One study included more than 1,000 people with relapsing-remitting MS. The study participants were randomly selected to receive a daily dose of 0.5 milligrams (mg), 1.25 mg or a placebo.

Annual relapse rates were less than 1 percent each year, and 54 percent less for the lower dose of Gilenya and 60 percent for the higher dose. The study also found slower disease activity and progression.

In the second study, 1,153 people with relapsing-remitting MS were randomly assigned to receive a daily dose of 0.5 mg or 1.25 mg of Gilenya or a weekly dose of 30 micrograms of interferon beta-1a (Avonex) for one year. The annual relapse rate on either drug was less than 1 percent in this study as well. However, the people on Gilenya had up to a 52 percent lower relapse rate. This study found no significant differences in disease progression between the two treatments.

Both studies found that the lower dose of the drug was better tolerated. A small number of serious infections occurred, including two deaths from herpes infections in these studies. And, there appeared to be a higher incidence of cancer in people taking Gilenya.

Novartis said Wednesday that the FDA approved a 0.5-milligram daily dose of Gilenya.

More information

To learn more, visit the National Multiple Sclerosis Society.