FDA Safety Warning for Gilenya and PML, Rare Brain Disease

August 29, 2013 — A person in Europe who was taking Gilenya  to treat multiple sclerosis has developed a rare but serious brain infection called progressive multifocal leukoencephalopathy (PML), according to a new FDA Drug Safety Communication. This is the first case of PML linked to Gilenya.

The FDA cautioned:

“Patients should not stop taking Gilenya without first discussing any questions or concerns with their health care professionals. We are providing this alert while we continue to investigate the PML case.”

According to Novartis, the patient who developed PML used Gilenya for nearly eight months. The patient took other medications before starting Gilenya. The patient did not take Tysabri (natalizumab), which is another MS drug that has been linked to PML. The patient was diagnosed based on symptoms and detection of JC virus DNA in their cerebrospinal fluid.

The case of PML was first reported in July 2013. Novartis reported that there were no other cases of PML among 71,000 patients who were treated with Gilenya.

What is PML?

Progressive Multifocal Leukoencephalopathy (PML) is a brain infection that usually causes severe disability or death. PML damages myelin, which is an insulating layer that forms around nerves in the brain and spinal cord. If myelin is damaged, electrical signals slow down.

PML caused by the John Cunningham (JC) virus. Although many people are infected with the JC virus, it is normally harmless, and only causes PML in people with weak immune systems. Medications like Gilenya, which weaken a patient’s immune system, may increase the risk of PML.

Symptoms and complications of PML:

• Paralysis
• Progressive weakness, clumsiness
• Blindness, double vision, or decreased vision
• Decreased ability to use a body part or limbs
• Seizures
• Speech problems (unable to understand or use language)
• Fatigue
• Loss of balance, falling
• Confusion, disorientation