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,

A French pharmaceutical giant is acquiring a Cambridge, Mass. biotech and its rare immunology disease treatment which is already approved in the U.S. and European Union.

The pharma giant wants to refreshen its portfolio after some of its internal development programs disappointed in clinical trials.