• HealthCare Royalty Receives Specified Milestones and Royalties for Ebvallo^TM in Europe in Exchange for Upfront Cash Payment to Atara
• Non-Dilutive Funding Further Extends Atara’s Cash Runway
• Incremental to $40 Million of Existing Milestones from Pierre Fabre Following Ebvallo^TM Marketing Authorization Approval and Filing for Application Transfer

Atara Biotherapeutics, Inc. (Nasdaq: ATRA), a leader in T-cell immunotherapy, leveraging its novel allogeneic Epstein-Barr virus (EBV) T-cell platform to develop transformative therapies for patients with cancer and autoimmune diseases, has entered into a royalty interest financing agreement totaling $31 million with HealthCare Royalty (HCRx) for Ebvallo™ in Europe and other territories covered by Atara’s commercialization agreement with Pierre Fabre.

“This strategic deal with HCRx, a top-tier investment firm, contributes to Atara’s financial position and reflects our positive momentum following the recent European Commission approval of Ebvallo™ as the only approved therapy for EU patients with a rare and potentially deadly cancer,” said Pascal Touchon, President and Chief Executive Officer of Atara. “We share HCRx’s confidence in Ebvallo™ and a vision of bringing a first ever allogeneic T-cell therapy to market in collaboration with our European commercialization partner Pierre Fabre.”

Under the terms of the agreement, Atara will receive a $31 million upfront payment from HCRx. In exchange, HCRx will receive rights to specified royalties and milestones under the Pierre Fabre commercialization agreement for Europe and other territories. The total royalties and milestones payable to HCRx are capped between 185 percent and 250 percent of the total investment amount by HCRx, dependent upon the timing of such royalties and milestones.

Additionally, Atara retains existing milestone payments from Pierre Fabre of $10 million for Ebvallo™ approval in Europe and $30 million for Atara’s initiation of the EU Marketing Authorization Application transfer to Pierre Fabre from the previously announced commercialization agreement and subsequent update announced in September 2022.

“We are proud to support Atara and have strong confidence in their mission of helping transform the lives of cancer and autoimmune patients through pioneering innovative science, proven by rigorous data,” said Clarke Futch, Chairman and Chief Executive Officer of HCRx. “Atara is a differentiated allogeneic T-cell immunotherapy company, and we are pleased to support their efforts at this pivotal moment for tabelecleucel development.”

About HealthCare Royalty

HCRx is a leading royalty acquisition company focused on commercial or near-commercial stage biopharmaceutical products. HCRx has $6.3 billion in cumulative capital commitments with offices in Stamford (CT), San Francisco, Boston, and London. For more information, visit www.hcrx.com. HEALTHCARE ROYALTY^® is a registered trademark of HealthCare Royalty Management, LLC in the U.S. and a trademark in other countries.

About Atara Biotherapeutics, Inc.

Atara Biotherapeutics, Inc. (@Atarabio) is a pioneer in T-cell immunotherapy leveraging its novel allogeneic EBV T-cell platform to develop transformative therapies for patients with serious diseases including solid tumors, hematologic cancers and autoimmune disease. With our lead program receiving marketing authorization in Europe, Atara is the most advanced allogeneic T-cell immunotherapy company and intends to rapidly deliver off-the-shelf treatments to patients with high unmet medical need. Our platform leverages the unique biology of EBV T cells and has the capability to treat a wide range of EBV-associated diseases, or other serious diseases through incorporation of engineered CARs (chimeric antigen receptors) or TCRs (T-cell receptors). Atara is applying this one platform, which does not require TCR or HLA gene editing, to create a robust pipeline including: tab-cel for Epstein-Barr virus positive post-transplant lymphoproliferative disease (EBV+ PTLD) and other EBV-driven diseases; ATA188, a T-cell immunotherapy targeting EBV antigens as a potential treatment for multiple sclerosis; and multiple next-generation chimeric antigen receptor T-cell (CAR-T) immunotherapies for both solid tumors and hematologic malignancies. Improving patients’ lives is our mission and we will never stop working to bring transformative therapies to those in need. Atara is headquartered in Southern California. For additional information about the company, please visit atarabio.com and follow us on Twitter and LinkedIn.

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 tab-cel®: the development, timing and progress of tab-cel®, the potential characteristics and benefits of tab-cel®, and, including the timing thereof, the amount and timing of potential royalties payable to HCRx or Atara by Pierre Fabre, and the royalty cap threshold to which such payments shall be subject. Because such statements deal with future events and are based on Atara’s current expectations, they are subject to various risks and uncertainties and actual results, performance or achievements of Atara 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, without limitation, risks and uncertainties associated with the costly and time-consuming pharmaceutical product development process and the uncertainty of clinical success; the COVID-19 pandemic, which may significantly impact (i) our business, research, clinical development plans and operations, including our operations in South San Francisco and Southern California and at our clinical trial sites, as well as the business or operations of our third-party manufacturer, contract research organizations or other third parties with whom we conduct business, (ii) our ability to access capital, and (iii) the value of our common stock; the sufficiency of Atara’s cash resources and need for additional capital; and other risks and uncertainties affecting Atara’s and its development programs, including those discussed in Atara’s filings with the Securities and Exchange Commission (SEC), including in the “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” sections of the Company’s most recently filed periodic reports on Form 10-K and Form 10-Q and subsequent filings and in the documents incorporated by reference therein. Except as otherwise required by law, Atara 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.