The Maryland-based firm said an acquisition could represent a better value for its stockholders than having the company continue to execute its business plan on a "stand-alone basis".
The company has been pressured by shareholders for several months but until now had decided to stick to its guns.
The most recent example was last February, when MedImmune received a letter from shareholder David Katz, president of Matrix Asset Advisors, which suggested it should consider a strategic sale, after revenue for the company's two top products came up short in Q4 results.
Sales of $18m (€13.4m) for the firm's influenza drug FluMist in the fourth quarter of 2006 missed investors' expectations by approximately $7m, while Synagis - a treatment for respiratory infections in children - generated $457m in sales, almost $20m below investors' estimates of $475m. MedImmune said at the time that its board of directors considered the sale option but after careful review decided it would "aggressively implement its business plan" rather than looking for acquisition alternatives.
However, indications of interest by major pharmaceutical companies, coupled with recent expressions by certain stockholders of dissatisfaction with the company's short-term stock price performance, have led the board to authorise management to gather information regarding possible strategic interest in acquiring the company, said the firm in a statement.
The firm remains tight-lipped about potential buyers or the expected selling price but said the process was "well under way" and is being managed by investment banks Goldman Sachs and Dewey Ballantine.
Company spokesperson Jamie Lacey told BioPharma-Reporter.com that it would not make any comments beyond the statement released yesterday, including a timeline for the sale process.
MedImmune, worth around $9bn, said its leading drug Synagis generated $1.1bn in revenue in 2006 and expects sales of the drug to be up 9 to 10 per cent for the first quarter of the year, according to preliminary results released this week.