Tran B. Nguyen M.B.A. — Chief Financial Officer at Prothena

Mr. Tran B. Nguyen, M.B.A. has been Chief Financial Officer of Prothena Corporation plc since March 2013 and served as its Principal Accounting Officer. Mr. Nguyen has 15 years of finance experience in the healthcare, banking and private equity industries. Prior to joining Prothena, he served as the Chief Financial Officer and Senior Vice President of Somaxon Pharmaceuticals, Inc. from April 12, 2010 to 2013 and from February 10, 2011 t o 2013 respectively and served as its Principal Accounting Officer until 2013. He served as Vice President of Corporate and Investment Banking at West Coast of Citigroup Inc. since May 24, 2007. He served as a Vice President at Pernix Sleep, Inc. from April 12, 2010 to February 10, 2011 and also served as its Chief Financial Officer since April 12, 2010, Senior Vice President since February 10, 2011 and Principal Accounting Officer. He served as Vice President of Finance and Principal Accounting Officer at Metabasis Therapeutics, Inc. He served as a Treasurer and Corporate Secretary of Metabasis Therapeutics Inc. He served as the Chief Financial Officer and Vice President at Metabasis Therapeutics Inc. since March 2009 and was primarily responsible for managing the financial operations. From May 2007 to January 2009, he was a part of the Healthcare Investment Banking group of Citi Global Markets Inc. as a Vice President, where he specialized in working with large-to-small capitalization biotechnology and specialty pharmaceutical companies. Prior to joining Citigroup Global Markets, he served as a Vice President of the Healthcare Investment Banking group at Lehman Brothers Inc., from January 2006 to April 2007 and as an Associate from July 2004 to December 2005. Prior to joining Lehman Brothers, he held various analytical financial positions at private equity and investment banking companies including CP Group, Waterton Management LLC, Merrill Lynch & Co. and Merrill Lynch International. He has been a Director of Sierra Oncology, Inc. since March 18, 2016. Mr. Nguyen holds B.A. degree in Economics and Psychology from Claremont McKenna College in 1995 and an M.B.A. degree from The Anderson School of Management at UCLA.