The Food and Drug Administration has issued an alert concerning the multiple sclerosis drug fingolimod, after a patient in Europe developed a rare and serious brain infection while taking the medication. Fingolimod is sold under the brand name Gilenya by Novartis (NYSE:NVS).
The agency says that this is the first reported case of the disease progressive multifocal leukoencephalopathy (PML) in a patient receiving Gilenya, who had not previously been on Tysabri (natalizumab), an intravenous MS drug previously associated with a higher risk of PML.
“Patients should not stop taking Gilenya without first discussing any questions or concerns with their health care professionals,” the FDA said in a statement posted on its website.
“We are providing this alert while we continue to investigate the PML case, and we are working with Gilenya’s manufacturer, Novartis, to obtain and review all available information about this occurrence. We will communicate our final conclusions and recommendations after our evaluation is complete.”
The patient had received nearly eight months of Gilenya before being diagnosed with PML. Both the FDA and Novartis noted that Gilenya was not the only drug the patient had been taking.
One month before initiating Gilenya treatment, the agency says the patient had been treated with interferon beta-1a and azathioprine. Those medications were stopped when Gilenya was started.
The patient also received multiple courses of intravenous corticosteroids for several months before and during Gilenya treatment.
While the FDA was careful not to attribute the occurrence of PML to Gilenya, Novartis, in no uncertain terms, said its drug is not to blame.
“Having reviewed all available information, Novartis considers that several features of this case of PML make it unlikely to be attributable to Gilenya,” the company said.
PML is a rare and serious brain infection caused by the John Cunningham (JC) virus that damages the fatty covering of the brain called myelin. Myelin is essential for the proper functioning of nerves in the white matter of the brain. PML usually causes death or severe disability.
While the JC virus is a common virus that is harmless in most people, it can cause PML in patients who have weakened immune systems, such as those with MS. Some medications, including Gilenya, can weaken the immune system.
Since its introduction three years ago, Novartis reports that approximately 71,000 patients worldwide have been treated with Gilenya.
The company reported that at least one patient developed PML shortly after switching to fingolimod from natalizumab, but says that natalizumab was likely responsible for that case.
Before the introduction Gilenya, a drug taken orally, the only medications available to treat MS were injectable. Gilenya was approved for use in the United States in 2010, followed by Aubagio (teriflunomide) from French drug maker Sanofi (NYSE: SNY) and Tecfidera (dimethyl fumarate), from Biogen Idec (NASDAQ: BIIB), which also manufactures Tysabri.
MS is a chronic disease which attacks the body’s central nervous system and destroys the myelin sheath that protects the nerve cells. An estimated 400,000 Americans have the disease and more than 2 million worldwide.
For most people with MS, relapses are initially followed by recovery periods or remissions. Symptoms may be mild or severe, ranging from numbness in the limbs to paralysis or loss of vision. The progression, severity and symptoms of MS are unpredictable and vary from one person to another. Over time, recovery periods may be incomplete, leading to progressive decline. There is no known cure.