Biogen Idec says that first-quarter 2007 profits increased 7%, while revenues were up 17% to $716 million, driven once again by the multiple sclerosis drug Avonex.

Net income was $132 million or $0.38 per share (+6%), a bit lower than analysts’ estimates due to higher costs, but sales of Avonex (interferon beta-1a) were higher than expected at $449 million, an increase of 14%. Revenues from the rheumatoid arthritis and cancer drug Rituxan (rituximab), which come from Biogen's joint venture with Genentech, rose 13% to $207 million.

Global sales of new MS drug Tysabri (natalizumab), which is partnered with Elan and only returned to the market in July last year after being pulled off on safety concerns in February 2005, reached $48 million and Biogen's share was $30 million.

Tysabri's reintroduction came with restrictions to monitor patients for symptoms of the rare brain disease PML (progressive multifocal leukoencephalopathy) but now 12,500 people have been prescribed with the drug and the company is confident that Tysabri will further penetrate the MS market.

Biogen reiterated that it expects total revenue growth in 2007 to be in the mid-teens percentage-wise and earnings should be in the range of $1.69-$1.84 per share, excluding any future transactions or acquisition.