Mr. Daniel G. Welch has been the Chairman of the company since 2015. Prior to this, he served as the Chairman, Chief Executive Officer and President of InterMune. Mr. Welch also served as the Chairman and Chief Executive Officer at Triangle Pharmaceuticals, Inc, President of the Pharmaceutical Division at Elan Corporation, PLC. Currently, he serves on the boards of directors of Seattle Genetics and Hyperion Therapeutics and Executive Partner at Sofinnova Ventures.

Dr. Emil D. Kakkis has been the Director, President and Chief Executive Officer of the company since 2010. Prior to this, he served as the Chief Medical Officer and Development Consultant at BioMarin Pharmaceutical Inc. Dr. Kakkis also served as the Board Member at National Organization for Rare Disorders. Currently, he serves as the President at EveryLife Foundation for Rare Diseases and Director of Odylia Therapeutics.

Mr. Howard Horn has been the Chief Financial Officer and Executive Vice President of the company since July 2023. Prior to this, he served as the Chief Financial Officer Vir Biotechnology.

Ms. Karah Parschauer has been the General Counsel, Executive Vice President and Chief Legal Officer of the company since 2016. Prior to this, she served in various leadership positions at Allergan PLC, including, Vice President, Associate General Counsel, Head of Legal and Compliance for Allergan’s Medical Aesthetic division and Chief Privacy Officer. She was also an associate attorney at Latham & Watkins LLP. Ms. Parschauer currently serves on the Board of Directors of Arcturus Therapeutics, Evolus and Tenaya Therapeutics.

Mr. Eric Crombez has been the Executive Vice President and Chief Medical Officer of the company since May 2023. Prior to this, he served as Ultragenyx’s Chief Medical Officer For Gene Therapy And Inborn Errors Of Metabolism. Previously he served at Shire in its Human Genetics Therapy business unit.