Less than a couple of months after asserting its desire to remain independent, US biotechnology company MedImmune now says it has retained the services of Goldman Sachs to explore the possibility of a sale.

As recently as February, the company’s board responded to a letter from one of its prominent shareholders, David Katz, president of Matrix Asset Advisors, who felt that MedImmune should put itself up for sale by saying that “the best way for the company to maximise value for its stockholders is to aggressively implement its business plan” on a stand-alone basis. However there has now been a change of heart.

The board now says that “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 it to authorise management “to gather information regarding possible strategic interest in acquiring the company.” Rumours of a possible takeover had been floating around since billionaire investor Carl Icahn disclosed in February that he owns 2.8 million shares of the company and its shares have been on the rise since then. This latest development pushed the stock up 15.3% to close at $43.63.

The jewel in MedImmune’s crown is the respiratory treatment Synagis (palivizumab), though its sales for 2006 were flat at $1.1 billion. Also the company recently announced that it is delaying the filing of Numax (motavizumab), its follow-on drug from Synagis, which might postpone the launch of the treatment to after September 2009.

It also markets the nasal spray flu vaccine FluMist and it is the vaccine angle that has led observers to mention Sanofi-Aventis, GlaxoSmithKline, Novartis and Merck & Co as possible bidders. Its expertise in biologics could also attract the attention of Wyeth, Eli Lilly and Abbott Laboratories. MedImmune’s market capitalisation currently stands at around $10.4 billion and analysts seem to think that an offer of $45-$50 per share will be needed to win control of the company.