Press Release

Audentes Therapeutics Expands Senior Leadership Team

Natalie Holles Appointed Chief Operating Officer, Thomas Soloway Appointed Chief Financial Officer and Kevin Baker, Ph.D. Appointed Senior Vice President, Preclinical Development

SAN FRANCISCO, CA – September 29, 2015 – Audentes Therapeutics, Inc., a biotechnology company committed to the development and commercialization of gene therapy products for patients with serious, rare diseases, today announced the addition of three accomplished biopharmaceutical executives to its leadership team. Natalie Holles has joined Audentes as Senior Vice President and Chief Operating Officer, Thomas Soloway has joined as Senior Vice President and Chief Financial Officer and Kevin Baker, Ph.D. has joined as Senior Vice President, Preclinical Development. In these newly created roles, each will report to Matthew Patterson, President and Chief Executive Officer of Audentes Therapeutics, Inc.

“It takes great people to build a great company and to achieve ambitious goals,” stated Mr. Patterson. “We are honored to have Natalie, Tom and Kevin join our team at this exciting time in our company’s growth, as their shared passion for our mission of serving patients with rare diseases combined with their proven leadership experience will greatly strengthen our ability to achieve our vision of becoming a leading gene therapy company.”

Ms. Holles joins Audentes with over 15 years of corporate development, strategic planning, and commercial experience, gained in a range of therapeutic areas and with a focus on orphan diseases. Most recently, Ms. Holles served as Senior Vice President, Corporate Development at Hyperion Therapeutics, Inc. from 2013 through its acquisition by Horizon Pharma, plc in May 2015. From 2010-2013, Ms. Holles provided executive-level strategy and business development advisory services to a number of privately-held biopharmaceutical companies, most recently acting as Executive Vice President, Corporate Development at Immune Design, Inc. Earlier in her career, Ms. Holles served as Vice President, Business Development at KAI Pharmaceuticals, Inc. (acquired by Amgen in 2012) and previously held corporate development and commercial roles at InterMune, Inc. (acquired by Roche in 2014) and Genentech, Inc. Ms. Holles holds an M.A. in molecular, cellular and developmental biology from the University of Colorado, Boulder, where she was a Howard Hughes Medical Institute Predoctoral Fellow, and an A.B. in Human Biology from Stanford University.

Mr. Soloway joins Audentes with over 20 years of experience in operations, corporate finance, and venture capital related to the life sciences industry. Prior to joining Audentes, Mr. Soloway served as the Senior Vice President, Chief Financial Officer of Ascendis Pharma A/S, a Danish biopharmaceutical company, where he helped lead a successful initial public offering on NASDAQ. Prior to Ascendis, Mr. Soloway co-founded Transcept Pharmaceuticals, Inc. At Transcept, Mr. Soloway held positions of increasing responsibility, serving initially as Senior Vice President, Operations and Chief Financial Officer and over time as Executive Vice President, Chief Operating Officer. In this role he oversaw project planning, manufacturing, pharmaceutical sciences, legal, human resources, regulatory and corporate communications. Prior to joining Transcept, Mr. Soloway financed and advised early stage healthcare and life sciences companies as a Principal at Montreux Equity Partners, a venture capital firm. Mr. Soloway earned a B.S. in Entrepreneurial Studies from the University of Southern California and an M.B.A. from Georgetown University.

Dr. Baker joins Audentes with over 20 years of experience in the discovery and development of novel biologic drugs for a wide range of diseases. Dr. Baker most recently served as Vice President, Preclinical Development at FivePrime Therapeutics, Inc. In this role, he led a multidisciplinary team that was responsible for advancing three therapeutics into the clinic to treat a variety of indications spanning oncology, immunology and other therapeutic areas. Prior to joining FivePrime in 2006, Dr. Baker served as Associate Director of Protein Therapeutics at Human Genome Sciences, Inc. (HGS), where he led a team responsible for progressing BENLYSTA, a novel FDA-approved therapeutic for the treatment of lupus, from research to Phase 2 clinical trials in autoimmune diseases. Prior to joining HGS, Dr. Baker was a scientist at Genentech, Inc., where he conducted research aimed at identifying novel therapeutics for cancer, autoimmune disease and cystic fibrosis. Dr. Baker received a B.Sc. in Biochemistry and Physiology from the University of Salford, England, earned a Ph.D. in Biochemistry from the University of Dundee, Scotland and conducted postdoctoral research in the department of biochemistry at the Biocenter, University of Basel, Switzerland.

About Audentes Therapeutics, Inc.

Audentes is a biotechnology company committed to the development and commercialization of innovative new treatments for people with serious, rare diseases through the application of AAV gene therapy technology. We have three products in development, AT001 for the treatment of X-Linked Myotubular Myopathy (XLMTM), AT002 for the treatment of Pompe disease, and AT003 for the treatment of the CASQ2 subtype of Catecholaminergic Polymorphic Ventricular Tachycardia (CASQ2-CPVT). Our team consists of focused, experienced, and passionate individuals committed to forging strong, global relationships with the patient, research, and medical communities. For more information regarding Audentes, please visit us atwww.audentestx.com.