FDA adds PML death scenario to Tecfidera label

When Biogen Idec ($BIIB) reported last month that a patient taking its hot multiple sclerosis pill Tecfidera had developed a rare brain infection and died, the drugmaker said it believed the safety profile of the drug remained solid. Perhaps so, but the FDA has decided the death was important enough to add a description of it on Tecfidera labels.

"The patient who died was not taking any other drugs that affect the immune system or drugs that are thought to be associated with PML (progressive multifocal leukoencephalopathy)," the agency said. "As a result, information describing this case of PML is being added to the Tecfidera drug label."

This is the only confirmed case of a death from the rare but serious brain infection reported in patients taking Tecfidera, the FDA said in a safety announcement accompanying the notice about the label change. The agency said patients taking Tecfidera who have any symptoms that concern them should let their doctors know right away.

PML is caused by the John Cunningham (JC) virus, a common virus that usually has no effect on people but can lead to PML in patients with suppressed immune systems, and MS drugs suppress patients' immune systems.

Biogen Idec CEO George Scangos

The European patient who died had been taking Tecfidera for four years, after starting on the drug during clinical trials, the company said last month. The patient died from pneumonia. "Despite this tragic loss, we believe the overall positive benefit-to-risk profile of Tecfidera remains unchanged," CEO George Scangos said during an earnings call in which he also reported that the drug had missed sales estimates.

Biogen has faced a similar issue with its infused MS drug Tysabri. The company took Tysabri off the market shortly after its launch in 2005 when some patients developed PML. It was returned the following year with a risk-management program and prescribing restrictions and has sold well since. It had sales of $501 million in Q3 2014. MS drugs come with risks, but patients are often willing to run them to have something that will help them deal with the debilitating affects of MS.

Pneumonia can also be a problem for MS patients with weakened immune systems, and Biogen last year investigated the death of a patient from pneumonia who was taking Tecfidera. That patient had been on the drug for about 5 weeks, went off because of gastrointestinal issues and died a couple of weeks later. It said at the time it didn't believe there was a connection.

The market was not fazed by the FDA announcement today. Biogen's shares were trading down less than a half percent late in the day.

- here's the FDA safety alert

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