Shares of Amarin Corp. PLC AMRN, +4.85% rose 4.8% in active afternoon trading Monday, after makers of drugs that rival Amarin’s Vascepa, which is used to lower the risk of cardiovascular events in patients with high triglyceride levels reported disappointing trial results. Trading volume in Amarin’s stock was 13.6 million shares, well above the full-day average of about 9.9 million shares. Acasti Pharma Inc. ACST, -64.36% said a phase 3 trial of CaPre failed to meets its primary endpoint, of reducing triglycerides by 20% compared with placebo. The median triglyceride reduction in patients taking CaPre was 30.5% while the median reduction of patients taking a placebo was 27.5%. Acasti’s stock plummeted 64% on volume of 48 million shares. And AstraZeneca PLC shares AZN, -0.50% fell 0.6% said it would discontinue the phase 3 trial of Epanova given its “low likelihood of demonstrating a benefit” to patients at increased risk of cardiovascular events, and that it would take a charge of up to $100 million as a result. Amarin’s stock has run up 30.5% over the past three months, while the S&P 500 SPX, +0.57% has gained 10.5%.