LONDON — The French drug maker Sanofi said on Monday that it had agreed to acquire Bioverativ, a biopharmaceutical company focused on treatments for hemophilia and other rare blood disorders, for $11.6 billion in cash.
Sanofi has sought use acquisitions to bolster its portfolio of drugs, particularly because it faces declining sales for its diabetes drug, Lantus, which has lost its patent protection. According to the company, sales of Lantus declined more than 16 percent in the first nine months of last year, based on constant exchange rates, and rivals are moving to introduce generic versions of the treatment.
The Bioverativ deal would enhance Sanofi’s “presence in specialty care and leadership in rare diseases” and “creates a platform for growth in other rare blood disorders,” Olivier Brandicourt, the Sanofi chief executive, said in a news release.
Bioverativ, based in Waltham, Mass., was spun out of Biogen last year. It markets two products to treat hemophilia in Australia, Canada, Japan and the United States. The company generated $847 million in sales in 2016.
John G. Cox, the Bioverativ chief executive, said, “Sanofi brings proven capabilities and a global infrastructure, which we believe will help to more rapidly expand access to our medicines globally and further our mission of transforming the lives of people with rare blood disorders.”
Under the terms of the deal, Sanofi would pay $105 in cash for each share of Bioverativ. That represented a 64 percent premium to Bioverativ’s closing price on Friday. Sanofi plans to finance the transaction with a combination of cash and debt.
The transaction is subject to regulatory approval and to a majority of Bioverativ’s shareholders agreeing to sell their shares. It is expected to close within three months.
The Bioverativ transaction marks Sanofi’s largest deal since it agreed to acquire Genzyme for $20.1 billion in 2011. In the interim, the French company has made several major bids for other drug makers, albeit unsuccessfully.
Medivation, a maker of prostate cancer drug treatments, rebuffed a takeover offer from Sanofi in 2016 and was ultimately acquired by Pfizer for $14 billion. Sanofi also missed a chance to acquire Actelion Pharmaceuticals, which was bought by Johnson & Johnson for $30 billion last year.
Lazard and the law firm Weil, Gotshal & Manges were advising Sanofi, while Guggenheim Securities and J.P. Morgan, and the law firm Paul, Weiss, Rifkind, Wharton & Garrison were advising Bioverativ.