Atara Biotherapeutics Announces Chief Financial Officer Intention to Retire in April 2018

Launches Search for Chief Financial Officer

SOUTH SAN FRANCISCO, Calif., Feb. 21, 2018 -- Atara Biotherapeutics, Inc. (Nasdaq:ATRA), a leading off-the-shelf T-cell immunotherapy company developing novel treatments for patients with cancer, autoimmune and viral diseases, today announced that John McGrath, Executive Vice President and Chief Financial Officer, intends to retire from the Company as of April 27, 2018.

“I want to thank John for his significant contributions since the founding of Atara in 2012,” said Isaac Ciechanover M.D., Chief Executive Officer and President of Atara Biotherapeutics. “We are grateful for his leadership and the opportunity to continue our relationship with him during this transition.”

“It has been a pleasure to serve as Atara’s CFO since the Company’s inception, and I am proud of the accomplishments we have made,” said Mr. McGrath. “I look forward to continuing to work with the company to help ensure this smooth transition.”

Atara is initiating a search for its next Chief Financial Officer who will play an instrumental leadership role in its continued evolution into a global commercial T‑cell immunotherapy company.

About Atara Biotherapeutics, Inc.
Atara Biotherapeutics, Inc. (@Atarabio) is a leading T-cell immunotherapy company developing novel treatments for patients with cancer, autoimmune and viral diseases. The Company's off-the-shelf, or allogeneic, T-cells are bioengineered from donors with healthy immune function and allow for rapid delivery from inventory to patients without a requirement for pretreatment. Atara's T-cell immunotherapies are designed to precisely recognize and eliminate cancerous or diseased cells without affecting normal, healthy cells. Atara's most advanced T-cell immunotherapy in development, tab-cel™ (tabelecleucel; formerly known as ATA129), is being developed for the treatment of patients with Epstein-Barr virus (EBV) associated post-transplant lymphoproliferative disorder (EBV+PTLD) who have failed rituximab, as well as other EBV associated hematologic and solid tumors, including nasopharyngeal carcinoma (NPC). Tab-cel™ is in Phase 3 clinical development for the treatment of EBV+PTLD following an allogeneic hematopoietic cell transplant (MATCH study) or solid organ transplant (ALLELE study), and a Phase 1/2 study of tab-cel™ in combination with Merck's anti-PD-1 (programmed death receptor-1) therapy, KEYTRUDA® (pembrolizumab), in patients with platinum-resistant or recurrent EBV associated NPC is planned for 2018. Tab-cel™ is also available to eligible patients with EBV associated hematologic and solid tumors through an ongoing multicenter expanded access protocol (EAP) clinical study. Off-the-shelf ATA188 and autologous ATA190, the Company's T-cell immunotherapies using a complementary targeted antigen recognition technology, target specific EBV antigens believed to be important for the potential treatment of multiple sclerosis (MS). A Phase 1 clinical study of autologous ATA190 in patients with progressive MS is ongoing. Atara also initiated a global Phase 1 ATA188 clinical study in patients with progressive or relapsing-remitting MS in Australia in the fourth quarter of 2017 with patient enrollment at U.S. sites beginning in early 2018. Atara's clinical pipeline also includes ATA520 targeting Wilms Tumor 1 (WT1) and ATA230 directed against cytomegalovirus (CMV).

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 ability to identify and retain its next chief financial officer; the timing, enrollment and results of the Company’s clinical trials; and the potential advantages of its product candidates. Because such statements deal with future events and are based on Atara Biotherapeutics' current expectations, they are subject to various risks and uncertainties and actual results, performance or achievements of Atara Biotherapeutics could differ materially from those described in or implied by the statements in this press release. These forward-looking statements are subject to risks and uncertainties, including the competitive market for executives in Atara Biotherapeutics’ industry and geography, as well as those discussed under the heading "Risk Factors" in Atara Biotherapeutics' quarterly report on Form 10-Q filed with the Securities and Exchange Commission (SEC) on November 9, 2017, including the documents incorporated by reference therein, and subsequent filings with the SEC. Except as otherwise required by law, Atara Biotherapeutics 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
650-410-3012
[email protected]

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

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