The drugmaker also announced a respectable jump of 26% in revenue to $893.3 million, up from $708.3 million a year earlier. Revenue during the period were helped by increased sales of Avonex and Tysabri drugs. Analysts had forecast $836.2 million in revenue, according to Thomson Financial.

Rituxan, a treatment for non-Hodgkins lymphoma and rheumatoid arthritis brought revenue of $254 million. Mutiple sclerosis treatment Avonex, the company's top-selling drug, also came with a 15% rise in sales to $503 million. On the other hand, sales of Tysabri, which was temporarily removed from the market in 2005 on safety worries, climbed to $90 million from $18 million a year ago.

Overall, Biogen had a strong past year, despite a deep fall in the month of December. Its strong sales, which jumped 18% to $3.17 billion in 2007, brought a full-year profit of $638 million, or $1.99 per share.

Looking ahead, Biogen reiterated its 2008 earnings outlook. Excluding one-time items, the drug maker predicted earnings of $3.20 to $3.35 a share, and revenue growth in a range between 15% and 2020%. The company's forecast matched analysts' predictions for earnings of 3.30 per share on sales of $3.586 billion.

So far investors are enjoying the company's better-than-expected earnings and its earnings outlook as its shares are up 1.62% to $61.50 in premarket trading. After its fall in December of last year, Biogen has shown a rebound over the past few months and I expect to see further gains based on its positive quarterly numbers.

Eliza Popescu is a financial writer for the online investment advisory service Investor's Observer.