Atara Bio’s Collaborator QIMR Berghofer Medical Research Institute Reports Positive Clinical Data for T Cell Immunotherapy in Nasopharyngeal Cancer (NPC), a Solid Tumor

Results Highlighted in Oral Presentation at the 2016 American Association for Cancer Research (AACR) Annual Meeting

Atara Bio and QIMR Berghofer Collaborating to Develop Next Generation "Off-the-Shelf" T Cell Immunotherapy for NPC and Other Diseases

SOUTH SAN FRANCISCO, Calif., April 19, 2016 (GLOBE NEWSWIRE) -- Atara Biotherapeutics, Inc. (Nasdaq:ATRA), a biopharmaceutical company focused on developing meaningful therapies for patients with severe and life-threatening diseases that have been underserved by scientific innovation, today announced that its collaborating investigators at QIMR Berghofer Medical Research Institute (“QIMR Berghofer”) presented positive Phase 1 clinical data for autologous targeted Epstein Barr Virus (EBV)-specific cytotoxic T lymphocytes (EBV-CTLs) at the AACR Annual Meeting, being held in New Orleans, LA, April 16-20. EBV-associated NPC accounts for approximately 6,000 cases annually in the US and EU combined and approximately 80,000 cases worldwide.

According to clinical results reported at the AACR meeting, 20 recurrent/metastatic NPC patients who received autologous targeted EBV-CTLs showed a median overall survival since the time of recruitment of 479 days. Additionally, nine patients treated by QIMR Berghofer had no radiographic or minimal residual disease (N/MRD). More than half of these patients remained free of progression at the time of analysis, with three patients exceeding three years.  These N/MRD patients had received a median of two prior treatments of chemotherapy and seven of these nine patients had experienced prior relapses.  The therapy was generally well-tolerated in the 29 patients with two patients experiencing possibly related grade 3 adverse events.

“These clinical findings provide initial data supporting the potential of EBV-targeted CTLs in a difficult to treat solid tumor that has a poor prognosis and extend Atara’s development programs beyond hematologic malignancies,” commented Chris Haqq M.D., Ph.D., Chief Medical Officer of Atara Bio. “The data also demonstrate the utility of the QIMR Berghofer technology, which we are leveraging to develop a next-generation allogeneic product for NPC and other EBV-associated diseases.  We believe that an allogeneic approach has important advantages, including the potentially enhanced immune effector function of healthy donor cells, improved manufacturability, and rapid availability.”

In October 2015, Atara Bio and QIMR Berghofer entered into exclusive license and research agreements under which Atara Bio has exclusive, worldwide rights to develop and commercialize allogeneic, or "off-the-shelf," CTLs targeted to multiple epitopes of EBV utilizing technology developed by QIMR Berghofer.  The QIMR Berghofer technology complements Atara Bio's ongoing CTL development efforts by selectively targeting specific epitopes and antigens of EBV that are associated with NPC and other diseases. Additional applications for which the technology may be appropriate include the treatment of gastric cancer, as well as certain autoimmune disorders, such as multiple sclerosis. In addition, Atara Bio has an option to license the autologous targeted EBV-CTL product candidate from QIMR Berghofer.

To obtain the full text of the abstract, please visit the AACR website link here. The details of the presentation are as follows:

Title: Therapeutic and Prophylactic AdE1-LMPpoly-Based Adoptive T cell Immunotherapy for Epstein–Barr Virus-Associated Nasopharyngeal Carcinoma
Date & Time: Tuesday, April 19, 2016, 4:15 PM - 4:30 PM Central Time
Publication Number: CT136
Session Title: Early Clinical Trials Evaluating Cell-based, Checkpoint Inhibitors, and Novel Immunotherapeutics
Session Type: Clinical Trials Minisymposium
Location: Room 343, Ernest N. Morial Convention Center, New Orleans, LA
Authors: C. Smith, A. Schuessler, J. Tsang, L. Beagley, V. Lee, B. Panizza, S. Porceddu, J. Nicholls, D. Kwong, and R. Khanna

About Targeted EBV-CTL

T cells are a critical component of the body's immune system and can be harnessed to counteract viral infections and some cancers. By focusing the T cells on specific proteins involved in cancers and infections, the power of the immune system can be employed to combat these diseases. Atara Bio's targeted EBV-CTL utilizes a technology in which T cells are collected from the blood of third-party donors and then activated to recognize specific epitopes of select EBV antigens implicated in certain solid tumors and autoimmune disorders such as NPC, gastric cancer, and multiple sclerosis. The resulting activated T cells are then expanded, characterized, and stored for future therapeutic use in an appropriate partially human leukocyte antigen, or HLA, matched patient, providing an “off-the-shelf,” allogeneic, cellular therapeutic option for patients.

About QIMR Berghofer Medical Research Institute

The QIMR Berghofer Medical Research Institute is a world leading translational research institute focused on cancer, infectious diseases, mental health and a range of complex disorders. Working in close collaboration with clinicians and other research institutes, QIMR Berghofer’s aim is to improve health by developing new diagnostics, better treatments and prevention strategies. The Institute's GMP facility, QGen Cell Therapeutics, is one of the largest facilities in Australia for the manufacture of cell therapies.  For more information about QIMR Berghofer, visit www.qimrberghofer.edu.au.

About Atara Biotherapeutics, Inc.

Atara Biotherapeutics, Inc. is a biopharmaceutical company focused on developing meaningful therapies for patients with severe and life-threatening diseases that have been underserved by scientific innovation, with an initial focus on immunotherapy and oncology. Atara Bio’s programs include T cell product candidates and molecularly targeted product candidates. The T cell product candidates include EBV-CTL, CMV-CTL and WT1-CTL and harness the power of the immune system to recognize and attack cancer cells and cells infected with certain viruses. The molecularly targeted product candidates include STM 434. These product candidates target activin and myostatin, members of the TGF-beta family of proteins, and have demonstrated the potential to have therapeutic benefit in a number of clinical indications.

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 continued progress of Atara Bio’s collaborator QIMR Berghofer Medical Research Institute (“QIMR Berghofer”) in advancing autologous targeted EBV-CTLs, the encouraging nature of results being presented at this year’s AACR Annual Meeting, the applicability of these results to allogeneic product development through the Atara-QIMR Berghofer collaboration, and the potential for the allogeneic approach to have important advantages including potentially enhanced immune effector function of healthy donor cells, improved manufacturability, and rapid availability. Because such statements deal with future events and are based on Atara Bio’s current expectations, they are subject to various risks and uncertainties and actual results, performance or achievements of Atara Bio 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 those discussed under the heading “Risk Factors” in Atara Bio’s annual report on Form 10-K filed with the Securities and Exchange Commission (SEC) on March 4, 2016, 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.

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sklass@burnsmc.com

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Released April 19, 2016