US biotech firm Medivation rejects Sanofi takeover bid

US biotech company Medivation rejected an unsolicited $9.3 billion bid from French pharmaceuticals giant Sanofi Friday, saying the offer "substantially undervalues" the company.

Medivation, which makes the lucrative prostate cancer drug Xtandi, said it is poised to soon commercialize other promising cancer drugs in development. Staying independent will be far more lucrative for Medivation shareholders than accepting Sanofi's proposal, Medivation said.

"Over the past several years, we have established a world class oncology franchise and a unique, diversified and highly-promising late-stage development pipeline," said David Hung, founder and chief executive officer of Medivation.

"Sanofi's opportunistically-timed proposal, which comes during a period of significant market dislocation, and prior to several important near-term events for the company, is designed to seize for Sanofi value that rightly belongs to our stockholders."

Sanofi disclosed its bid for Medivation on Thursday after being frustrated by a lack of response from the American drugs maker two weeks after submitting an unsolicited offer.