Boston Scientific Corp. has agreed to acquire private firm Nxthera Inc., a specialist in minimally invasive treatment of benign prostatic hyperplasia (BPH), for an upfront cash payment of $306 million, followed by as much as $100 million in possible milestone payments across the next four years. Boston Scientific is currently a minority investor in Nxthera and will make a $240 million net payment at closing, with milestones of as much as $85 million. The deal is expected to close in the second quarter of 2018.