Sept. 22, 2010 -- The FDA today approved Novartis' Gilenya, the first oral drug for multiple sclerosis (MS). Gilenya (formerly spelled Gilenia, generic name fingolimod) last June received the overwhelming approval of an FDA expert advisory panel.

Gilenya treats the relapsing form of MS. The drug significantly reduces MS attacks. However, it has serious side effects, with possible heart, lung, and eye toxicity and increased risk of infection. Patients must be closely monitored, and regular eye exams are advised.

In MS, white blood cells attack the myelin sheaths that protect nerve cells. Gilenya, the first drug in its class, keeps white blood cells penned up in lymph nodes by taking away the chemical key they need to unlock the lymph node door.

Fewer white blood cells mean fewer MS attacks. But it also means less protection against infections. Novartis will set up a careful program for educating and monitoring patients taking the drug. Moreover, the company will continue long-term studies to look for side effects that may occur with longer-term use.

Gilenya was invented as a new way to prevent rejection in kidney transplant patients. But at the necessary dosage, the drug was far too toxic. The dose that would be used to treat MS is five times lower than the lowest dose tested in the transplant studies.

Even at this dosage, Gilenya can have severe toxicity. In clinical trials, side effects linked to Gilenya included:

    * Elevated liver enzymes
    * Macular edema (swelling of the central portion of the retina, causing distorted vision)
    * Elevated blood pressure
    * Shortness of breath
    * Bronchitis
    * Diarrhea
    * Bradycardia (slowing of the heartbeat, seen only upon first treatment. The FDA panel recommended that patients be required to receive their first dose under medical supervision).

Two fatal herpes infections occurred in MS patients treated with Gilenya at 2.5 times the FDA-approved 0.5 mg dose. Novartis is not seeking approval for higher dosages.

Overall, the drug's benefits outweighed its risks among the more than 2,600 MS patients who took the drug in clinical trials.