Feuerstein's Biotech-Stock Mailbag

Tysabri is still very much a second-line multiple sclerosis drug, being prescribed to about 14% of patients who fail first-line interferons. Interestingly, Teva's(TEVA Quote) Copaxone is being prescribed to more (35%) interferon failures.

Forty percent of responding doctors want to see 1-3 years of additional safety data on Tysabri before they're comfortable prescribing the drug as a first-line treatment. Another 32% of doctors in the survey want to see 4-6 years of additional safety data.

The big safety worry with Tysabri is progressive multifocal leukoencephalopathy, or PML. Doctors in the survey say that one additional case of PML reported in a Tysabri patient would reduce use of the drug by 26%.

Multiple sclerosis patients are also wary of Tysabri's safety risks, with 36% of Tysabri-eligible patients refusing to take the drug.

Now, I recognize this is just one survey and that there are certainly others conducted by Wall Street's sell-side community that are more bullish. Nevertheless, it raises good thinking points about Biogen Idec's aggressive forecast.

This, in turn, could affect the bidding for Biogen Idec. For the record, Werber gives 70% odds that Biogen Idec does get bought. And he believes $85 is a good price. He has a hold rating on Biogen Idec and Citigroup provides banking services to the company.

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