Privately held Italian drugmaker Menarini Group said on Monday it would buy U.S. company Stemline Therapeutics Inc in a deal valued at up to $677 million, looking to gain access to a U.S. approved drug for a rare blood disease.

Stemline’s lead cancer drug Elzonris, which brought in $43.2 million in estimated net revenue in 2019, would bolster Menarini’s cancer drug portfolio. Stemline shareholders will get $12.50 per share, involving an upfront payment of $11.50 in cash, which represents a premium of more than 140% to Stemline’s closing price on Friday. Each shareholder would be entitled to an additional $1 in cash per share upon completion of certain milestones, the companies said.