Europe Reviews Tysabri Over Brain Infections

European regulators said in a report published late last week that the number of cases of a rare brain infection linked to Biogen'sTysabri multiple sclerosis drug are much higher than previously disclosed. And so the European Medicines Agency is reviewing the benefits and risks of the med, which is already under tight regulatory supervision in the US, The Pink Sheet reports.

The EMEA counted 23 cases of the brain infection PML since Tysabri reentered the market in 2006 (here is the press release). Three more cases came to light during clinical trials, pushing the total to 26 out of more than 46,000 patients who have received the drug. The last count by the FDA was 13 cases given patients in the general population.

Tysabri was originally granted a fast-track approval by the FDA in late 2004 because it appeared much more effective at slowing the symptoms of multiple sclerosis than current treatments. Regulators will be weighing those benefits as they re-consider what seems to be a growing risk of PML, a potentially deadly brain infection caused by a common virus that only attacks people with compromised immune systems. The first clinical cases of PML knocked Tysabri off the market soon after launch.

The drug was removed from the market shortly after its 2005 launch over PML links and was back on the market in July 2006. But Biogen admitted in its quarterly earnings call last week that the risk of PML infection increases the longer a patient takes Tysabri. Biogen is working on a label change, just one month after the FDA released a safety alert. Biogen insists the overall risk of infection remains roughly 1 in 1,000.

In a research note today, Cowen & Co. analyst Ian Sanderson writes that the issue for the FDA and the EMEA is whether additional measures beyond the current REMS program are required to ensure safe use, although neither agency is considering removing Tysabri. "We believe physicians and patients will become incrementally cautious in their Tysabri use as the number of PML cases continues to rise, so we are cutting Tysabri patient estimates by 55 percent to 60 percent in 2015 - to 25,000 patients from our previous target of 59,000 patients - reflecting 10 percent average annual decline from today's 46,000 patient population," he concludes.

Disclosure: Ed Silverman is an editor at The Pink Sheet

4 Comments

Oct 26, 2009 - 10:53am

Ed: I believe your earlier reply to me said you link to these so-called breaking stories by the Pink Sheet when they offer your readers something out of the ordinary. This story was reported last friday by most major news media outlets. So, what's so different about the Pink Sheet or is this again part of your agreemenrt with Elsevier to promote its products?

Oct 26, 2009 - 10:56am

ED: Forgot to mention that I'm glad to see you added a proper disclosure at the bottom of your piece.

Hi Mole,

First, if you notice, I didn't post anything since last Friday morning. So I chose to get to it today, since Tysabri is always making news and my experience from the past is that not everyone notices breaking news or other items that occur on a Friday.

To answer your question, this is what I wrote in a previous comment to you: "I’m perfectly happy, however, to mention and link to stories from The Pink Sheet when they’re newsworthy - which could mean exclusive, insightful or simply different things that I’ve not seen elsewhere."

In this case, the Pink Sheet story about Tysabri was more detailed than what I saw on Bloomberg or in The Boston Globe, which were essentially long briefs.

Of course, there's a rub here. I had to walk a fine line - I included the basic info from The Pink Sheet, but I'm prevented from posting the entire story as part of my arrangement with my employer. So how would you know it's more detailed than other media? You won't unless you subscribe. Sorry, I can't help that. But I didn't omit necessary info.

At times, this may be an imperfect situation. But I've tried to be upfront about this. Like it or not, this is where things stand - my arrangement allows me to run Pharmalot on a part-time basis so as long as it doesn't cause some conflict with my job. And if there's an opportunity to post an item that offers sufficient info from the Pink Sheet, I'm happy to do so.

Meanwhile, I appreciate that you enjoy monitoring my activities. And please let me know if you believe an item appears to be illegitimate. By the way, I've disclosed my employment in all of the posts that linked to the Pink Sheet, as well as on the 'About Pharmalot' page - that detail was actually updated on the page several weeks ago.

Regards ed

Oct 26, 2009 - 12:08pm

Mole Gerbil, your concerns would be considered more legit if you provided us with your real name..