Shares of Blueprint Medicines Corp. (NASDAQ:BPMC) soared 26.5% after Sanofi (NASDAQ:SNY) revealed plans to acquire the biopharmaceutical company in a deal valued at approximately $9.5 billion. The acquisition strengthens Sanofi’s rare disease and immunology portfolio,

Blueprint, based in Cambridge, has an approved drug called Ayvakit that treats a rare immunological condition.

France's Sanofi has agreed to buy U.S.-based Blueprint Medicines Corporation for up to $9.5 billion to boost its position in rare immunology diseases, in the biggest deal struck by a European healthcare company so far this year,