GW Pharmaceutical PLC /zigman2/quotes/209686240/composite GWPH +0.55% shares rallied Monday after the cannabis-based medicine company forecast better-than-expected sales of its seizure treatment Epidiolex. U.S. shares of GW surged 7.4% to $115.44 in recent activity. The company said it expects fourth-quarter revenue of about $108 million for the fourth quarter and about $309 million for the year. Analysts surveyed by FactSet estimate revenue of $102.4 million for the fourth quarter and $304.6 million for the year, up from a previous estimate of $100.2 million for the quarter and $302.1 million for the year. The company expects Epidiolex sales of about $104 million for the fourth quarter and about $296 million for the full year. "Our fourth quarter and full year results for 2019 reflect an exceptional launch year for Epidiolex," said Justin Gover, GW chief executive, in a statement. "Our goal in 2020 is not only to continue to drive Epidiolex growth but also to leverage our world leadership in cannabinoid science to advance our pipeline."