Sanofi SA SNY 0.83 % on Thursday said it sent a letter to Medivation Inc. MDVN 0.27 % saying it would try to remove and replace members of the U.S. biotech firm’s board if it didn’t engage in takeover talks.
The Paris-based drugmaker, which has a record of hostile takeovers in the biotech sector, said in the letter that it has had “extensive conversations” with Medivation’s shareholders and that it believes there is “overwhelming support” for a deal.
“If you are not prepared to engage with us, we have no choice but to go directly to your shareholders,” the company said.
Medivation on Thursday reiterated its rejection of Sanofi’s “substantially inadequate proposal.”
“Sanofi’s letter simply restates an inadequate proposal that the Medivation board of directors has already determined substantially undervalues the company, its leading oncology franchise, and innovative late-stage pipeline,” the company said in a statement.
Sanofi last week said it was ready to approach Medivation shareholders after the board rejected its $9.3 billion offer, opening the way for a protracted takeover battle. Sanofi’s offer of $52.50 a share represented a 50% premium to Medivation’s average share price for the two months before takeover speculation emerged. However, it is now below Medivation’s share price, which closed Thursday at $59.22, up 16 cents.
In the letter, Sanofi said it could increase its offer if the Medivation board engages in good faith discussions.
Medivation, a Nasdaq-listed company that focuses on hard-to-treat cancers, markets one prostate-cancer therapy, Xtandi, and has two other oncology assets in clinical development.
A takeover of Medivation would allow Sanofi to significantly expand its drugs portfolio while it is under pressure to launch innovative medicines to make up for declining sales of its blockbuster Lantus insulin.
“We remain enthusiastic about a potential combination with Medivation. We and our advisers stand ready to meet at any time so we can work to quickly consummate a mutually beneficial transaction,” Sanofi said in the letter.
Later Thursday, Medivation said it swung to a profit in the first quarter and reaffirmed 2016 earnings and sales guidance.
The company earned $4.8 million, or 3 cents a share, compared with a loss of $3.1 million, or 2 cents a share, a year earlier. Collaboration revenue rose to $182.5 million from $129.2 million.
Earnings excluding items were 11 cents a share.
Analysts polled by Thomson Reuters had projected earnings excluding items of 23 cents a share on revenue of $196.6 million.
—Josh Beckerman contributed to this article.
Anne Steele at Anne.Steele@wsj.com