Dean J. Mitchell has served as a director since June 2014. Mr. Mitchell has served as Executive Chairman of the board of directors of Covis Pharma Holdings, a specialty pharmaceutical company, since August 2013, Chairman of PaxVax Corporation, a specialty vaccine company, since January 2016, and on the board of directors of ImmunoGen Inc., a public oncology company, since 2012 and Intrexon, Inc., a synthetic biology company, since 2009. Within the past five years, he also served as a director of Ista Pharmaceuticals, Inc., a specialty pharmaceutical company, Lux Biosciences, Inc., a biopharmaceutical company, and Talecris Biotherapeutics Holdings Corp., a biopharmaceutical company. Mr. Mitchell served as President and Chief Executive Officer of Lux Biosciences, Inc., a biotechnology company focusing on the treatment of ophthalmic diseases, from July 2010 to August 2013. Prior to Lux Biosciences, he served as President and Chief Executive Officer of both Alpharma, Inc., a publicly traded specialty pharmaceutical company, from 2006 until its acquisition by King Pharmaceuticals, Inc. in 2008, and Guilford Pharmaceuticals, Inc., a publicly traded pharmaceutical company focused in oncology and acute care, from 2004 until its acquisition by MGI Pharma Inc. in 2005. From 2001 to 2004 he served in various senior executive capacities in the worldwide medicines group of Bristol-Myers Squibb Company, a pharmaceutical company. Prior to the Bristol-Myers Squibb Company, he spent 14 years at GlaxoSmithKline plc, in assignments of increasing responsibility spanning sales, marketing, general management, commercial strategy and clinical development and product strategy. Mr. Mitchell holds an M.B.A. from City University London and a B.Sc. in biology from Coventry University. 

 ophthalmic diseases