An indictment was unsealed today charging a former U.S. citizen with engaging in an insider trading scheme involving the stock of Humanigen Inc., a publicly traded biopharmaceutical company. Dale Chappell, 54, who was formerly the chief scientific officer and member of the Board of Directors of Humanigen, was arrested on Dec. 20 in Switzerland based on the U.S. criminal charges. The United States will seek Chappell’s extradition to stand trial in the District of New Jersey.