Charles Cohen, Ph.D., has been a director since November 1995. Dr. Cohen is an independent investor and from March 2015 to May 2019, he served as Chief Executive Officer and as a member of the board of directors of Perform Biologics, Inc., a privately held biotechnology start-up company. Previously, Dr. Cohen served as Chief Executive Officer and as a member of the board of directors of On Target Therapeutics, LLC, a privately held biotechnology start-up company, from June 2015 to June 2017. From May 2007 to December 2015, Dr. Cohen was a managing director of Synthesis Capital (formerly Advent Healthcare Ventures), a venture capital firm. From 2003 to 2007, Dr. Cohen was Vice President of Advent International, a global private equity firm.