Atara Biotherapeutics Enhances Commercial Expertise with the Appointment of Dr. Derrell Porter to the Executive Leadership Team

SOUTH SAN FRANCISCO, Calif., May 10, 2017 -- Atara Biotherapeutics, Inc. (Nasdaq:ATRA) today announced the appointment of Dr. Derrell Porter as Senior Vice President and Global Commercial Head. Dr. Porter brings extensive commercialization experience to the management team as Atara moves towards Phase 3 studies of its most advanced allogeneic T-cell product candidate, ATA129, for patients with rituximab refractory Epstein-Barr virus associated Post-Transplant Lymphoproliferative Disease (EBV-PTLD) in 2017.  The Company also expects to submit ATA129 for conditional marketing authorization in the EU in 2018.

"We are pleased to have Derrell join our leadership team,” said Isaac Ciechanover, Chief Executive Officer and President of Atara Biotherapeutics. “He brings extensive global commercial experience that will be instrumental as we plan to bring ATA129 to EBV-PTLD patients in key markets as well as advance our diverse immunotherapy pipeline.”

Prior to joining Atara, Dr. Porter was a Vice President with Gilead Sciences, where he was responsible for corporate strategy, long term commercial planning and global launch preparation in oncology, immunology, HIV and liver diseases including HCV. During his tenure at Gilead, he led commercial preparation for eight global brands and built a global pricing and market access function as well as developed Gilead’s competitive intelligence capabilities. Previously he was with AbbVie and Amgen, where he held multiple US, EU and global commercial leadership roles of increasing responsibility in business unit and brand management, marketing and sales.

Dr. Porter started his career at McKinsey & Company where he worked on global biopharmaceutical engagements. Dr. Porter currently serves on the board of directors for Biosortia Pharmaceuticals. He holds a B.S. from UCLA, an M.D. from University of Pennsylvania’s Perelman School of Medicine where he was a Gamble Scholar, and an M.B.A. from The Wharton School.

About Atara’s “Off-the-Shelf” Allogeneic Immunotherapy Platform
Atara’s immunotherapy platform provides healthy immune capability to a patient and arms the immune system to precisely target and combat disease. T-cells derived from healthy donors are manufactured in advance and stored as inventory so that a customized unit of T-cells can be chosen for each patient. The T-cells are ready to infuse in approximately 3 to 5 days. Once administered, the T-cells home to their target, expand in-vivo to eliminate diseased cells, and eventually recede. This versatile platform can be directed towards a broad array of disease causing targets and has demonstrated clinical proof of concept across both viral and non-viral targets in conditions ranging from hematologic  and solid cancers to autoimmune and infectious diseases. The Company has pursued prospective feedback from health authorities on both manufacturing and clinical trial design. Atara’s lead product candidate, ATA129, has the potential to be the first commercial “off-the-shelf” allogeneic T-cell therapy for a viral target implicated in cancer.

About Atara Biotherapeutics, Inc.
Atara Biotherapeutics, Inc. is a biopharmaceutical company developing meaningful therapies for patients with severe and life-threatening diseases who have been underserved by scientific innovation, with an initial focus on allogeneic T-cell therapies for cancer, autoimmune, and infectious disease. Atara's T-cell product candidates harness the power of the immune system to recognize and attack cancer cells and cells infected with certain viruses. The Company's initial clinical stage T-cell product candidates include Epstein-Barr virus targeted Cytotoxic T-cells (EBV-CTL), or ATA129, Cytomegalovirus targeted Cytotoxic T-cells (CMV-CTL), or ATA230, and Wilms Tumor 1 targeted Cytotoxic T-cells (WT1-CTL), or ATA520. These product candidates have demonstrated the potential to have therapeutic benefit in a number of clinical indications including hematologic malignancies, solid tumors, and refractory viral infections. The Company is also developing a next generation of T-cell product candidates utilizing a technology to selectively enhance a T-cell's ability to target specific viral proteins implicated in a disease. The Company’s ATA188 product candidate leverages this technology. Initial clinical investigations employing this approach will focus on multiple sclerosis and other virally mediated cancers.

Forward-Looking Statements
This press release contains or may imply "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. For example, forward-looking statements include statements regarding: the Company’s plan to move towards Phase 3 clinical trials for ATA129 and to submit ATA129 for conditional marketing authorization in the EU in 2018; the commercialization of ATA129 for EBV-PTLD patients in key markets; and the advancement of the Company’s diverse immunotherapy pipeline. These forward-looking statements are subject to risks and uncertainties, including those discussed under the heading "Risk Factors" in Atara Bio's annual report on Form 10-Q filed with the Securities and Exchange Commission (SEC) on May 4, 2017, including the documents incorporated by reference therein, and subsequent filings with the SEC. Except as otherwise required by law, Atara Bio disclaims any intention or obligation to update or revise any forward-looking statements, which speak only as of the date hereof, whether as a result of new information, future events or circumstances or otherwise.

INVESTOR & MEDIA CONTACTS:

Investors:
John Craighead, Atara Biotherapeutics
650-491-5806
[email protected]

Steve Klass, Burns McClellan
212-213-0006 x331
[email protected]

Media:
Justin Jackson, Burns McClellan
212-213-0006 x327
[email protected]