UCB SA agreed to buy Ra Pharmaceuticals Inc. for about $2.5 billion to join forces with one of its largest competitors in developing a rare-disease medicine, the field behind many recent industry tie-ups.
The Belgian drugmaker will pay $48 a share in cash for Cambridge, Massachusetts-based Ra Pharmaceuticals, UCB said Thursday. That’s more than double the U.S. company’s closing price Wednesday. The shares traded at $45.63 as of 10:29 a.m. in New York.