GW Pharmaceuticals PLC said late Monday that it had a positive phase-three trial result for its Epidiolex drug. GW stock rose more than 7% in after-hours trading. Epidiolex is a drug that contains cannabidiol, or CBD, a compound found in cannabis plants. The drug is an anti-epilepsy medication and the phase-three trial was performed on 224 patients in six countries. GW said it was the fifth consecutive positive trial for Epidiolex. GW stock has gained 28% in the past year, as the S&P 500 index rose 11%.