Gilenya (generic name, fingolimod) would be used for the relapsing form of MS. The drug significantly reduces MS attacks. However, it has serious side effects, with possible heart, lung, liver, and eye toxicity and increased risk of infection. Patients must be closely monitored, the panel advised.
Gilenya is the first drug in its class. In MS, white blood cells attack the myelin sheathes that protect nerve cells. Gilenya 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 and cancers. Novartis has already promised to 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. The FDA panel recommended that Novartis be required to study whether even lower doses of the drug might be effective in MS.
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)
- High blood pressure
- Shortness of breath
- Bradycardia (slowing of the heartbeat, seen only upon first treatment. The FDA panel recommends 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 0.5 mg dose for which Novartis is seeking approval.
So far, no more cancers have been seen in MS patients taking Gilenya than in patients taking an inactive placebo.