Feuerstein's Biotech-Stock Mailbag

Right, that sounds confusing. I had to read the note several times to understand the dynamics. I'm not going to try to explain it further. Suffice to say, Werber doesn't believe Genentech will try to muck up any deal to acquire Biogen Idec.

That said, Genentech still has the financial upper hand in the Rituxan partnership, which includes follow-on, second-generation versions of the lucrative drug. That has to factor into the decision-making process of any potential Biogen Idec acquirer.

There's one more thing from Werber that adds another cautionary note to the entire buyout thesis: Demand for the multiple sclerosis drug Tysabri is increasing, but Biogen Idec's guidance for the drug's growth appears too aggressive.

Werber reaches that conclusion after surveying 50 neurologists who treat about 6% of all treated MS patients in the U.S., asking them about their attitudes toward Tysabri and their current and future prescribing plans.

Remember, Biogen Idec's forecast calls for Tysabri patients to grow from about 17,000 today to 100,000 by the end of 2010. That translates into $2 billion to $3 billion in annual Tysabri revenue. It seems logical to assume that any potential acquirer of Biogen Idec needs to believe in this growth forecast to make a takeover work financially.

Werber's survey, however, definitely raises some questions about whether Biogen Idec and partner Elan(ELN Quote) can achieve the 100,000 Tysabri patient goal. Some highlights: