Biogen's Tysabri wins the blockbuster crown

Biogen Idec CEO James Mullen (photo) failed to impress investors yesterday with a "glowing" report on sales of multiple sclerosis remedy Tysabri. Biogen shares dropped despite the news that Tysabri won the blockbuster crown in 2009 by posting sales of $1 billion plus and the drug's sales growth has accelerated.

By the end of 2009, Biogen says in a statement, almost 49,000 patients were using Tysabri. That's 30 percent growth year-over-year--and this despite the growing number of progressive multifocal leukoencephalopathy cases among Tysabri users. At last count, there were 28 cases of PML since Tysabri came back on the market in 2006. Obviously, that's not much of a deterrent for the MS patients turning to the drug.

So what's the worry? Apparently investors still aren't satisfied with Tysabri's growth. Shareholders including Carl Icahn continue to agitate for a sale or breakup of the company. And Mullen just announced he would retire (though that move sent the stock upward). Then there's the danger that PML cases will continue to climb--and eventually eclipse the 1-in-1,000 risk that's now on Tysabri's label.

But for now, Mullen can bask in the blockbuster glow. "Tysabri did achieve blockbuster status, something many thought it never could do,'' Mullen said at the J.P. Morgan healthcare conference. "This is going to continue to grow and continue to surprise people.''

- check out the release from Biogen
- see the Bloomberg story
- get more from Dow Jones
- read the Boston Globe piece