Novartis' MS drug Gilenya tied to rare brain infection

Novartis' ($NVS) Gilenya, which a consumer watchdog group last year pegged with safety concerns, is again being called into question after a patient taking the multiple sclerosis drug developed a rare brain infection.

The FDA sent out a safety alert today saying that this is the first case of progressive multifocal leukoencephalopathy, or PML, in a patient taking Gilenya who had not already received the MS drug Tysabri. Biogen Idec's ($BIIB) Tysabri is associated with a higher risk of PML, the agency said. The FDA and Novartis are investigating the case, and the agency will give its recommendations once that is complete. It warned patients to talk with their doctors before discontinuing the drug.

But it also pointed out that PML "usually causes death or severe disability." It said the condition is caused by John Cunningham (JC) virus, which is common and usually harmless, but can lead to PML in people whose immune systems are weak. And Gilenya works by suppressing the immune system.

Novartis in a statement to Reuters said it let the FDA know in July about the report but believes it is unlikely the infection is tied to Gilenya since the patient had not been taking the drug that long. "With over 71,000 patients having been treated with Gilenya, there has been no previous case of PML attributable to Gilenya," Novartis said.

But it has been tied to a number of other adverse reactions, some in patients who have died. In fact, the Institute for Safe Medication Practices last year pointed out that Gilenya's powerful immunosuppressant action--key to its effectiveness--can also trigger powerful side effects. It suggested Novartis and the FDA consider limiting its use after sifting through adverse event reports and finding the drug had been linked to 11 deaths. Both the FDA and European regulators have reviewed the drug because of concerns. In Europe, it was recently one of 100 drugs tagged with a black triangle label that encourages the reporting of serious side effects.

For all of the safety concerns, Gilenya is the first oral drug for multiple sclerosis found to actually modify the course of the disease. And because multiple sclerosis is such a debilitating--and life-threatening--disease, some patients are willing to risk serious side effects if a drug is proven beneficial.  

Gilenya is not the only treatment the patient received, the FDA pointed out. The patient had been taking Gilenya for 8 months before being diagnosed with PML but had been treated with interferon beta-1a and azathioprine for a month before starting Gilenya. The person also received intravenous corticosteroids for several months before and during Gilenya treatment, the FDA said.

Novartis has run into some other issues around Gilenya. A U.S. Attorney's Office in New York last month demanded documents and information about the company's promotions of the drug.  

- read the FDA alert
- more from Reuters

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