A Tysabri Turnaround Or A Head Fake?

Carl Icahn
Shiho Fukada
Carl Icahn

Carl Icahn and all of the Elanians should be happy.

Biogen Idec today reported encouraging trendsregarding its all-important multiple sclerosis drug Tysabri.

BIIB and Ireland's Elan are partners on the drug.

And Icahn is a BIIB investor who recently won a couple of seats on the company's board of directors.

Tysabri is an injectable drug that helps cut the frequency and severity of MS flare-ups. But recently, some analysts and investors have expressed concern about Tysabri's prospects because of a pickup in the number of reported cases of a very rare, potentially fatal side effect. The company responded by giving weekly updates on PML reports, but today BIIB said it'll stop doing that next week. The company pulled the drug off the market after the condition known as PML first cropped up, but later got FDA permission to bring it back to the market three years ago.

I covered the meeting of the FDA panel that considered whether to recommend Tysabri's return. Nearly all of these advisory committee meetings can be extremely dense and dull. It's not uncommon to see several people nodding off in the middle of the meeting. But the Tysabri affair was emotional and, at times, powerful and moving. A few of the MS patients who testified were crying, begging the panel to let the drug come back. Despite the known risk of death, they believed the benefits were too strong.

Doctors have become more vigilant about PML and they now know how to quickly flush the drug out of the patient's system and get them out of danger. Since Tysabri has come back to market there have been 10 known PML cases, but only one of them was fatal. Experts think that the longer a patient is on Tysabri, the greater the chances are of getting PML, so they expect the number of cases to continue to pile up in coming months. On the conference call, analysts say execs indicated they're looking at treatment alternatives like possibly taking a Tysabri break and they're trying to figure out why most of the new cases are occurring overseas.

Because there'd been some analyst chatter about the acceleration of PML cases causing a slowdown in Tysabri sales, many were surprised today to see BIIB report that the number of patients on Tysabri is actually growing, sales are climbing and the rate at which new patients are going on the drug is picking up as well. The company now says that Tysabri is on track to become a billion-dollar blockbuster. Still, some analysts are cautious and don't think Tysabri is out of the woods yet.

I hope the apparent turnaround for the franchise will encourage Biogen Idec's CEO Jim Mullen to get back out there. He used to regularly give us an interview, but I don't think he's been on CNBC since 2007.

Carl, can you help?

Questions? Comments? Pharma@cnbc.com and follow me on Twitter at mhuckman