Atara Biotherapeutics Announces Two Presentations at MSParis2017, Including Updated, Interim Results from a Phase 1 Study of Autologous ATA188 in Patients with Progressive Multiple Sclerosis (MS)

New results characterizing the molecular signature of Epstein-Barr Virus (EBV) in MS brain lesions will also be presented

Presentations to take place during the upcoming MSParis2017 Congress, the 7th Joint Meeting of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) and the Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS)

SOUTH SAN FRANCISCO, Calif., July 31, 2017 -- Atara Biotherapeutics, Inc. (Nasdaq:ATRA), a leading cell therapy company developing novel treatments for patients with cancer and multiple sclerosis (MS), today announced that the Company’s collaborating investigators will present results from two studies during the upcoming MSParis 2017 Congress.

Updated, interim results will be presented from a Phase 1 study of an autologous version of ATA188, an Epstein-Barr Virus (EBV) specific T-cell immunotherapy, conducted by the Company’s collaborating investigators at the QIMR Berghofer Medical Research Institute and The University of Queensland.  The meeting will also feature new results by Atara and its collaborating investigators at Stanford Medicine characterizing the molecular signature of EBV in MS brain lesions. The MSParis2017 Congress will be held October 25-28, 2017, at the Palais des Congrès de Paris, in Paris, France. Details for the poster presentations are as follows:

Abstract Title: Safety and clinical improvement in a phase 1 trial of autologous Epstein-Barr virus-specific T cell therapy in patients with progressive multiple sclerosis
Session Title: Poster Session 1
Presentation Date & Time: Thursday, October 26, 2017; 15:30 CEST
Lead Authors: Michael Pender, M.D., and Professor Rajiv Khanna

Abstract Title: Molecular signature of Epstein-Barr virus infection in multiple sclerosis brain lesions
Session Title: Poster Session 2
Presentation Date & Time: Friday, October 27, 2017; 15:30 CEST
Lead Authors: May Han, M.D., and Lawrence Steinman, M.D.

About ATA188
Epstein-Barr Virus (EBV) is associated with a wide range of hematologic malignancies and solid tumors, as well as certain autoimmune conditions such as multiple sclerosis (MS). T-cells are a critical component of the body's immune system and can selectively target specific EBV antigens believed to be important for the potential treatment of MS. ATA188, the Company’s next generation T-cell immunotherapy for autoimmune diseases, has the potential to precisely recognize and eliminate EBV-infected B-cells and plasma cells in the central nervous system that may catalyze autoimmune responses and MS pathophysiology. As reported at the American Academy of Neurology (AAN) meeting in April 2017, the first study to test adoptive immunotherapy in patients with MS showed that autologous ATA188 led to encouraging clinical improvements in MS symptoms that correlated with the EBV reactivity of ATA188 in 3 of 6 patients. In addition, no patient in the study experienced progression of disability or worsening in Expanded Disability Status Scale (EDSS). Additional reported results are available at this link. In addition to the ongoing Phase 1 clinical study of autologous ATA188 in progressive forms of MS, a Phase 1 allogeneic ATA188 clinical study is expected to begin in the second half of 2017.

About Progressive Multiple Sclerosis
Progressive Multiple Sclerosis (PMS) is a severe disease with few therapeutic options. PMS comprises two conditions, both characterized by persistent progression and worsening of MS symptoms and physical disability over time. This is distinct from Relapsing Remitting MS (RRMS) where flares of the disease are followed by periods of recovery and quiescence. Primary Progressive MS (PPMS) occurs when continuous progressive disease is present at diagnosis.  Secondary Progressive MS (SPMS) initially begins as RRMS and develops into a progressive form. There is substantial unmet medical need for new and effective therapies for patients with PPMS and SPMS.  Most treatment options that work well in reducing flares in RRMS have not been shown to be effective in slowing or reversing disability in PMS.

About Atara Biotherapeutics, Inc.
Atara Biotherapeutics, Inc. (@Atarabio) is a leading cell therapy company developing novel treatments for patients with cancer and multiple sclerosis (MS). The Company’s “off-the-shelf”, or allogeneic, T-cells are engineered 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, ATA129, is being developed for the treatment of cancer patients with rituximab refractory Epstein-Barr virus (EBV) associated post-transplant lymphoproliferative disorder (EBV-PTLD), as well as other EBV positive hematologic and solid tumors including nasopharyngeal carcinoma (NPC). Phase 3 clinical studies of ATA129 in EBV-PTLD are expected to start in the second half of 2017 and a Phase 1/2 clinical study in NPC is planned for 2018. In addition, Atara expects to submit a conditional marketing authorization for ATA129 in the EU in 2018. ATA188, the Company’s next generation T-cell immunotherapy for autoimmune diseases, selectively targets specific EBV antigens believed to be important for the potential treatment of multiple sclerosis (MS). A Phase 1 clinical study of autologous ATA188 in progressive forms of MS is ongoing, and a Phase 1 allogeneic ATA188 clinical study is expected to begin in the second half of 2017. Atara’s clinical pipeline also includes ATA520 targeting Wilms Tumor 1 (WT1) and ATA230 directed against cytomegalovirus (CMV).

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]