News

— Accelerates Two Development-Stage Compounds —
— Appoints Joel Marcus as New Board Member —

BRISBANE, Calif. and THOUSAND OAKS, Calif., December 17, 2013 – Atara Biotherapeutics, Inc., a drug development company with a focus on innovative therapies for patients with debilitating diseases, announced today that it has secured $38.5 million in initial closings under its Series B financing. In this round, investors Amgen Ventures (Nasdaq: AMGN), Celgene Corporation (Nasdaq: CELG), and EcoR1 Capital, joined existing investors Alexandria Venture Investments, DAG Ventures, Domain Associates, and Kleiner Perkins Caufield & Byers,

Proceeds will be used to accelerate the clinical development of Atara’s two lead programs, PINTA 745 and STM 434, which are expected to generate new clinical data within the next 18 months.

“We founded Atara with the goal of accelerating the development of novel biologic compounds to bring meaningful therapeutic advances to conditions underserved by innovation in recent years,” said Isaac Ciechanover, MD, chief executive officer of Atara.  “This financing allows us to advance our pipeline and moves us closer to achieving our mission of addressing substantial unmet medical needs.”

Within only 15 months of its founding, the Atara team initiated a Phase 2 pilot trial of PINTA 745, a myostatin inhibiting peptibody, being investigated as a potential treatment for protein energy wasting (PEW), a form of inflammation, malnutrition and muscle wasting in patients with end-stage renal disease. PEW is a condition that correlates with adverse outcomes and increased mortality in patients with chronic renal disease receiving dialysis.  This condition affects a significant proportion of the 400,000 patients in the US who annually undergo treatment with dialysis.  The goals of this Phase 2 trial are to assess PINTA 745 potential effects on lean body mass, physical function, quality of life and other outcomes for these patients.

In addition, the Atara team plans to submit an investigational new drug (IND) application to the US Food and Drug Administration to conduct a first-in-human, Phase 1 study of STM 434, an inhibitor of activin.  STM 434 represents a novel targeted approach for the treatment of ovarian cancer as well as other solid tumors.   Considered the deadliest cancer for women, ovarian cancer kills approximately 125,000 globally each year.  Pre-clinical data with Atara’s activin inhibitors suggest an anti-tumor effect as a single agent and additive benefit in combination with chemotherapy.

In conjunction with the financing, Atara announced that it has appointed Joel Marcus, chairman, chief executive officer, and founder of Alexandria Real Estate Equities, Inc. (NYSE: ARE) / Alexandria Venture Investments to the board of directors of the Atara family of companies.

“Atara has moved quickly to build a pipeline of innovative, targeted therapies designed to address the underlying mechanisms of disease, and disease states for which there are few therapeutic options today,” said Mr. Marcus.  “The company has employed a strategic business structure that provides optionality for value creation.  I am honored to join the board and the world-class team that Isaac is assembling.”

The financing described above relates to three biotechnology entities – Nina Biotherapeutics, Inc., Pinta Biotherapeutics, Inc., and Santa Maria Biotherapeutics, Inc. – in the Atara family of companies.  Atara’s unique structure was designed to help enable investors to preserve optionality and maximize potential value creation.  Atara has raised more than $58 million to date for this family of companies.

About Atara Biotherapeutics

Atara Biotherapeutics, Inc. is a privately-held drug development company with a focus on innovative therapies for patients with debilitating diseases. The research of Atara and its family of companies is based on groundbreaking discoveries regarding the ability of activin, myostatin and other biological targets to change the course of disease progression.  Atara has three novel biologics in development, including PINTA 745 (Phase 2) for protein energy wasting in end-stage renal disease, STM 434 (IND-ready) for ovarian cancer and other solid tumors, and NINA 842 (pre-clinical) for cancer-related cachexia.   Atara and its family of companies were launched in 2012 by a proven team of drug developers, Amgen, and Kleiner Perkins Caufield & Byers.  For more information, please visit www.atarabio.com.

Investor Contact:
Matt Clawson
matt@allencaron.com
949-474-4300

Media Contact:
Dan Budwick, Pure Communications
dan@purecommunicationsinc.com
973-271-6085

A team of oncology researchers including Dr. Christopher Haqq, Atara Biotherapeutics’ Chief Medical Officer, presented a poster at the June 2013 annual meeting of the American Society of Clinical Oncology in Chicago. The findings were published in the Journal of Clinical Oncology: “Effects of a soluble activin type 2B receptor Fc fusion protein (STM 217) in TOV-21G, a mouse xenograft model of clear cell ovarian cancer.” The study, led by John Lu, HQ Han and Haqq, demonstrated that inhibition of activin signaling by use of a ligand trap results in antitumor activity as a monotherapy, and that additive activity was observed in combination with chemotherapy. Increases in body weight were not impaired by concomitant administration of 5-FU chemotherapy. This study suggests that a phase 1 clinical trial of activin inhibition in metastatic ovarian cancer is warranted. (Abstract)

AMGEN AND KLEINER PERKINS CAUFIELD & BYERS PARTNER TO CREATE NEW SPIN-OUT BIOTECH COMPANY

Amgen to License Pipeline Assets to Newly Formed Company

THOUSAND OAKS, Calif. and MENLO PARK, Calif. (Oct. 25, 2012) – Amgen and Kleiner Perkins Caufield & Byers (KPCB) today announced the formation of Atara Biotherapeutics, (www.atarabio.com), a new drug development company with a focus on innovative therapies for patients with chronic diseases in therapeutic areas including nephrology and oncology. Atara Biotherapeutics will have licenses to six Amgen assets, which are in various stages of development, ranging from preclinical to Phase 1. Financial terms of the transaction are not being disclosed.

Atara Biotherapeutics will be financed initially by KPCB, and Isaac Ciechanover, M.D., a former partner at KPCB, will serve as the president and chief executive officer. Amgen will have a minority equity interest in Atara Biotherapeutics.

“Amgen is excited to partner with KPCB to help advance molecules in Amgen’s pipeline that have the potential to treat serious illnesses,” said Sean E. Harper, M.D., executive vice president of Research and Development at Amgen. “With facilities in both the Bay Area and near Amgen’s Thousand Oaks campus, Atara Biotherapeutics will provide the opportunity to further foster biotechnology innovation in Amgen’s communities.”

“We look forward to building on Amgen’s research to bring a promising group of therapeutics to patients with serious illnesses,” said Ciechanover.

About Amgen
Amgen discovers, develops, manufactures and delivers innovative human therapeutics. A biotechnology pioneer since 1980, Amgen was one of the first companies to realize the new science’s promise by bringing safe and effective medicines from lab to manufacturing plant to patient. Amgen therapeutics have changed the practice of medicine, helping millions of people around the world in the fight against cancer, kidney disease, rheumatoid arthritis, bone disease and other serious illnesses. With a deep and broad pipeline of potential new medicines, Amgen remains committed to advancing science to dramatically improve people’s lives. To learn more about our pioneering science and our vital medicines, visit www.amgen.com. Follow us on www.twitter.com/amgen.

About Kleiner Perkins
Kleiner Perkins Caufield & Byers (KPCB) has backed entrepreneurs in more than 500 ventures leading to 150 IPOs, 350,000 jobs and a deep strategic network. The firm has helped build pioneering companies like Align, Amazon, Electronic Arts, Genentech, Genomic Health, Google, Intuit, Juniper Networks, Netscape, Symantec, VeriSign and WebMD. KPCB partners serve on the boards of Amazon, Apple, Bloom Energy, Flipboard, Foundation Medicine, Google, Hewlett-Packard, Nest, Square, Tesaro and Zynga, among others. KPCB accelerates the success of entrepreneurs with a team of partners delivering company-building services including strategy, operational scaling, recruiting, business development and product delivery. The firm invests in all stages from seed and incubation to growth companies. KPCB operates from offices in Menlo Park, San Francisco, Shanghai and Beijing. http://www.kpcb.com.

Forward-Looking Statements
This news release contains forward-looking statements that involve significant risks and uncertainties, including those discussed below and others that can be found in Amgen’s Form 10-K for the year ended Dec. 31, 2011, and in its periodic reports on Form 10-Q and Form 8-K. Amgen is providing this information as of the date of this news release and does not undertake any obligation to update any forward-looking statements contained in this document as a result of new information, future events or otherwise.

No forward-looking statement can be guaranteed and actual results may differ materially from those Amgen projects. Amgen’s results may be affected by Amgen’s ability to successfully market both new and existing products domestically and internationally, clinical and regulatory developments (domestic or foreign) involving current and future products, sales growth of recently launched products, competition from other products (domestic or foreign), difficulties or delays in manufacturing its products. In addition, sales of Amgen products are affected by reimbursement policies imposed by third-party payors, including governments, private insurance plans and managed care providers and may be affected by regulatory, clinical and guideline developments and domestic and international trends toward managed care and healthcare cost containment as well as U.S. legislation affecting pharmaceutical pricing and reimbursement. Government and others’ regulations and reimbursement policies may affect the development, usage and pricing of Amgen products. Furthermore, Amgen’s research, testing, pricing, marketing and other operations are subject to extensive regulation by domestic and foreign government regulatory authorities. Amgen or others could identify safety, side effects or manufacturing problems with Amgen products after they are on the market. Amgen’s business may be impacted by government investigations, litigation and products liability claims. Further, while Amgen routinely obtains patents for its products and technology, the protection offered by its patents and patent applications may be challenged, invalidated or circumvented by its competitors. Amgen depends on third parties for a significant portion of its manufacturing capacity for the supply of certain of its current and future products and limits on supply may constrain sales of certain of its current products and product candidate development. In addition, Amgen competes with other companies with respect to some of its marketed products as well as for the discovery and development of new products. Discovery or identification of new product candidates cannot be guaranteed and movement from concept to product is uncertain; consequently, there can be no guarantee that any particular product candidate will be successful and become a commercial product. Further, some raw materials, medical devices and component parts for Amgen products are supplied by sole third-party suppliers. Amgen’s business performance could affect or limit the ability of its Board of Directors to declare a dividend or its ability to pay a dividend or repurchase its common stock.