Shares of SteadyMed Ltd. rocketed 75% to pace the premarket gainers early Monday, after the specialty pharmaceutical company agreed to be acquired by United Therapeutics Corp. in a deal valued at $216 million, including contingent payments. United Therapeutics stock was indicated up less than 1% ahead of the open. Under terms of the deal, SteadyMed shareholders will receive $4.46 a share in cash for each SteadyMed share they own, which is 68% above Friday's closing price of $2.65, and would value SteadyMed at $118.5 million. SteadyMed shareholders could also receive up to $2.63 a share in if it achieves commercialization milestones related to Trevyent, a development-stage drug device used in the treatment of pulmonary arterial hypertension. "We believe that this proposed acquisition will help us realize our commitment to bring Trevyent to market to improve the lives of patients with PAH," said SteadyMed Chief Executive Jonathan Rigby. SteadyMed's stock had tumbled 28.4% year to date through Friday, while United Therapeutic shares had shed 25.4% and the S&P 500 had eased 0.1%.