Biogen Idec prices a public offering

Biogen Idec Inc. said it has priced a public offering of $1 billion principal amount of senior unsecured notes.

The Cambridge company markets such drugs as Rituxan for non-Hodgkins lymphoma and rheumatoid arthritis and Avonex, a multiple sclerosis drug; with another firm, it markets a second MS drug called Tysabri.

Biogen Idec said the offering of senior unsecured notes includes $450 million in aggregate principal amount of 6.0 percent notes due 2013 and $550 million in aggregate principal amount of 6.875 percent notes due 2018.

Sale of the notes is expected to close March 4.

The company plans to use the net proceeds from this offering, together with cash on hand, to repay indebtedness under its $1.5 billion bridge facility, the proceeds of which were used to repurchase shares of Biogen Idec's common stock in a $3 billion "Dutch Auction" tender offer settled July 2.
(By Chris Reidy, Globe staff)