Mr. Ellberger was appointed Chairman of the Board of Directors of Celldex in September 2009. Mr. Ellberger has been an independent member of the Celldex Board of Directors since the merger between Celldex and AVANT Immunotherapeutics in March 2008 and had been a director of AVANT since 2003. From 2003 to July 2012, he was Founding Partner of HVA, a consulting firm specializing in business development, product acquisition and licensing, and mergers and acquisitions for pharmaceutical, biotechnology, drug delivery and medical device companies. He served as Chairman of the Board of Omrix Biopharmaceuticals until its acquisition by Johnson & Johnson in 2008. From October 2005 to May 2016, Mr. Ellberger was interim Chief Executive Officer of PDI, where he had been serving as a Director and Chairman of the Audit Committee. Mr. Ellberger was a Board member and Senior Vice President of Powderject plc from 2000 to 2003. From 1995 to 1999, Mr. Ellberger was an officer of W.R. Grace & Co., serving as interim Chief Executive Officer, Chief Financial Officer and Senior Vice President, Strategic Planning and Development. From 1975 to 1995, Mr. Ellberger held numerous senior executive positions at American Cyanamid Company, serving the last four years as Vice President, Corporate Development. Mr. Ellberger is a director of NeuroDerm, a NASDAQ-listed Israeli biotech company, and is a member of its audit and nominating committees. He is also a director of The Jewish Children’s Museum. He received a B.A. in economics from Columbia College and a B.Sc. in Chemical Engineering from Columbia School of Engineering.