Shares of PhaseBio Pharmaceuticals Inc. more than doubled in premarket trade Monday, soaring 112% toward a record high, after the biopharmaceutical company announced positive phase 1 trial results of PB2452, a reversal agent for the antiplatelet drug ticagrelor. The trial showed that the effects of PB2452 were immediate, with sustained reversal of ticagrelor antiplatelet effects without reports of drug-related serious adverse events. "The data support further evaluation of PB2452 for the reversal of the antiplatelet effects of ticagrelor in emergency situations involving major bleeding and to enable emergent or urgent surgery in patients," said Deepak Bhatt, executive director of Interventional Cardiovascular Programs at Brigham and Women's Hospital. The company is planning to initiate a phase 2a trial in the first half of this year. The stock, which went public in October, has lost 9.5% over the past three months through Friday, while the iShares Nasdaq Biotechnology ETF has run up 16% and the S&P 500 has gained 11%.