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Atara Bio Announces Clinical Trial Results for the Treatment of EBV+ Nasopharyngeal Carcinoma using Allogeneic Epstein-Barr Virus Cytotoxic T-Lymphocyte Product Candidate

SOUTH SAN FRANCISCO, Calif., June 06, 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 Memorial Sloan Kettering Cancer Center (MSK) reported clinical results for Atara's allogeneic Epstein-Barr Virus Cytotoxic T-Lymphocyte (EBV-CTL) product candidate. Data were presented from an on-going Phase 2 clinical trial, which enrolled a heterogeneous group of EBV associated malignancies including NPC and post-transplant lymphoproliferative disorders, at an oral presentation at the ASCO 2016 Annual Meeting. This data included safety and efficacy of EBV-CTL in the treatment of 14 patients with recurrent metastatic nasopharyngeal carcinoma (NPC). EBV-associated NPC accounts for approximately 6,000 cases annually in the US and EU combined and approximately 80,000 cases worldwide. Historical median survival rates range from five to eleven months for patients with metastatic disease.

Dr. Susan Prockop, M.D., and colleagues reported the following data:

  • A 21% objective response rate in NPC patients, including one complete response, and two partial responses.
  • 11 of the 14 NPC patients were alive with median 18-month follow-up.
  • EBV-CTLs expanded after administration to immunocompetent NPC patients without concomitant lymphodepleting chemotherapy.
  • Of the 126 patients enrolled across all indications, there were two grade 4 and seven grade 3 possibly related serious adverse events.

"We are pleased that this study has demonstrated the potential therapeutic benefit of an allogeneic therapy for patients with solid tumors," commented Chris Haqq M.D., Ph.D., Chief Medical Officer of Atara Bio. "We look forward to developing this product candidate as both a single agent and in combination with other therapies in NPC and other indications. In addition, we will be commencing our two upcoming pivotal trials in patients with rituximab refractory EBV Post-Transplant Lymphoproliferative Disorder (EBV-PTLD) after solid organ transplant (SOT) and hematopoietic stem cell transplant (HCT) later this year."

About 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 EBV-CTL utilizes a technology in which T cells are collected from the blood of third-party donors and then exposed to EBV antigens. 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. EBV-CTLs are designed to find cancer cells expressing EBV and kill them. Phase 2 clinical results from trials conducted at MSK have been reported in multiple peer-reviewed forums. Atara Bio plans to commence two pivotal clinical trials of EBV-CTL for rituximab-refractory EBV Post-Transplant Lymphoproliferative Disorder (EBV-PTLD) following hematopoietic cell transplant (HCT), as well as solid organ transplant (SOT), towards the end of 2016.

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 development of our EBV product as a single agent and in combination with other therapies, and the commencement of our pivotal trials in rituximab refractory EBV Post-Transplant Lymphoproliferative Disorder (EBV-PTLD) after solid organ transplant (SOT) later this year. 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-Q filed with the Securities and Exchange Commission (SEC) on May 6, 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.


INVESTOR & MEDIA CONTACT: Investors: Steve Klass 212-213-0006 x331 sklass@burnsmc.com Media: Justin Jackson 212-213-0006 x327 jjackson@burnsmc.com

Source:Atara Biotherapeutics, Inc.