Sanofi the French drugmaker went public on Thursday with its offer of $9.3 billion to acquire U.S. cancer company Medivation after the company had rebuffed original approaches.

The plan to target Medivation returns Sanofi the biotech company to the takeover trail as it looks for new treatments for cancer to add to its portfolio and to help it offset the dropping sales of Lantus its diabetes drug.

The non-binding proposal from Sanofi is to acquire Medivation at a price of $52.50 in cash per share, which represents a premium of 50% over the firm’s volume-weighted two-month average share price before takeover rumors came to light.

It is nevertheless only slightly above the closing price for Medivation on Wednesday of $52.05, which reflects the run-up in the price of the stock over the past few weeks due to talks of a bid.

Last month it was reported that Medivation was working with JPMorgan the investment bank to handle the interest from businesses regarding a possible acquisition but it was not planning on selling itself.

An analyst in the industry said that Sanofi could now be facing a drawn out fight to takeover Medivation with other companies possibly becoming involved including Astellas Pharma based in Japan, a partner of Medivation on Xtandi its drug for prostate cancer.

AstraZeneca, based in Britain, has reported to be looking at Medivation as well.

AstraZeneca and Astellas officials would not comment on the issue although a person close to AstraZeneca said it was not likely the company would enter into any bidding war.

Sanofi, whose shares were down 2% in weaker mid morning European markets on Thursday, said there was not any certainty the deal would be completed, but if it were, it would boost their earnings immediately.

Analysts with Deutsche Bank said that Sanofi likely could use significant flexibility in order to increase its offer, given the current low cost of obtaining debt.

The premium to the price offered by the French company is below other recent larger deals in the biotech industry, with Roche handing over a premium of 63% for its 2014 acquisition of Intermune.

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