David E. Robinson has resigned from his position as chairman, president, chief executive officer and as a director of Ligand Pharmaceuticals, Inc., effective immediately. After consultation with the company’s board of directors, Mr. Robinson resigned to pursue other opportunities. Current director, Henry F. Blissenbach has been named chairman and interim chief executive officer of the company. Dr. Blissenbach has served on the board of directors since May 1995, and recently retired as pres...