Atara Biotherapeutics Strengthens Board; Senior Management Team

— Matthew K. Fust joins Board of Directors —
— Mitchall G. Clark named Chief Regulatory and Quality Assurance Officer —

BRISBANE and THOUSAND OAKS, Calif., April 8, 2014 – Atara Biotherapeutics, Inc., a drug development company with a focus on innovative therapies for patients with debilitating diseases, announced today that it has strengthened its board of directors and executive team by appointing Matthew K. Fust as a director and hiring Mitchall G. Clark, B.Pharm, as chief regulatory and quality assurance officer.

Mr. Fust most recently served for five years as executive vice president and chief financial officer of Onyx Pharmaceuticals, where his responsibilities included the corporate finance, accounting, and information technology organizations, along with other operating functions at the company. Prior to Onyx, Fust spent more than five years as senior vice president and chief financial officer of Palo Alto, California-based Jazz Pharmaceuticals, and prior to that he was CFO at Mountain View, California-based Perlegen Sciences and at Mountain View, California-based ALZA Corporation. Fust currently serves as a board member and audit committee chair at Rockville, Maryland-based MacroGenics, South San Francisco, California-based Sunesis Pharmaceuticals, and Novato, California-based Ultragenyx Pharmaceutical.

Prior to joining Atara, Mr. Clark was senior vice president, regulatory affairs at Los Angeles-based Nantworks Group of Companies where he established the regulatory affairs function. Prior to that he was senior vice president, regulatory affairs at Abraxis where he led the regulatory team responsible for the global regulatory approvals of Abraxane® at Celgene Corporation after the Abraxis acquisition. In addition, Clark spent more than 13 years in senior management positions at a number of pharmaceutical companies including American Pharmaceutical Partners, Inc. and VivoRX, Inc.

“We have sought to build a board and management team that have world class biopharmaceutical credentials,” said Isaac Ciechanover, MD, chief executive officer of Atara.  “We are fortunate that these two seasoned and accomplished individuals have chosen to join the Atara team.  Matt is a leader in pharmaceutical company management and finance, and his experience and guidance will be a great asset to the board and the entire organization.  Mitch Clark is also a recognized industry leader and has broad experience in regulatory affairs, having built companies from formation through commercialization. His experience taking compounds from IND to approval on aggressive schedules should serve Atara, and ultimately patients, well.”

About Atara Biotherapeutics

Atara Biotherapeutics, Inc. is a privately-held drug development company with a focus on innovative therapies for patients with debilitating diseases. The company’s lead programs are focused on myostatin and activin, members of the TGF-beta family of proteins that have demonstrated the potential to have therapeutic benefit in a number of clinical indications.  Atara was launched in 2012 by a proven team of drug developers, and Kleiner Perkins Caufield & Byers.  For more information, please visit www.atarabio.com.

Investor Contact:
Matt Clawson
matt@allencaron.com
949-474-4300

Media Contact:
Dan Budwick, Pure Communications
dan@purecommunicationsinc.com
973-271-6085