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Unless the context otherwise requires, we use the terms Atara, Atara Biotherapeutics, Atara Bio,
Company, we, us and our in this Exhibit 99.1 to refer to Atara Biotherapeutics, Inc. and, where appropriate, our consolidated subsidiaries.
Special Note Regarding Forward-Looking Statements
This Exhibit 99.1 contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the
Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act. These statements relate to future events or to our future operating or financial performance and involve known and unknown risks,
uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performances or achievements expressed or implied by the forward-looking statements. Forward-looking
statements may include, but are not limited to, statements about:
All statements other than statements of
historical facts contained in this Exhibit 99.1 are forward-looking statements. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be
materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. This Exhibit 99.1 also contains estimates and other statistical data made by independent parties and by us relating to
market size and growth and other data about our industry. This data involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. In addition, projections, assumptions and estimates of our future
performance and the future performance of the markets in which we operate are necessarily subject to a high degree of uncertainty and risk.
cases, you can identify forward-looking statements by terms such as may, will, should, expect, plan, anticipate, could, intend, target,
project, contemplate, believe, estimate, predict, potential or continue or the negative of these terms or other similar expressions. The forward-looking statements
in this Exhibit 99.1 are only predictions. We have based these forward-looking statements largely on our
current expectations and projections about future events and financial trends that we believe may affect our business, financial condition and results of operations. These forward-looking
statements speak only as of the date of this Exhibit 99.1 and are subject to a number of risks, uncertainties and assumptions, including those under the heading Risk Factors below and under the heading Risk Factors in our
Quarterly Report on Form 10-Q for the period ended September 30, 2017, filed with the Securities and Exchange Commission on November 9, 2017. The events and circumstances reflected in our
forward-looking statements may not be achieved or occur and actual results could differ materially from those projected in the forward-looking statements. Moreover, we operate in an evolving environment. New risk factors and uncertainties may emerge
from time to time, and it is not possible for management to predict all risk factors and uncertainties. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained in this Exhibit 99.1,
whether as a result of any new information, future events, changed circumstances or otherwise.
Investing in our common stock involves a high degree of risk. You should carefully consider all of the risk factors and uncertainties
described below and those under the heading Risk Factors in our Quarterly Report on Form 10-Q for the period ended September 30, 2017, filed with the Securities and Exchange Commission on
November 9, 2017, before investing in our common stock. If any of the following risks materialize, our business, financial condition and results of operations could be seriously harmed. In these circumstances, the market price of our common
stock could decline, and you may lose all or a part of your investment.
The recently passed comprehensive tax reform bill could adversely
affect our business and financial condition.
On December 22, 2017, President Trump signed into law the Tax Cuts and Jobs Act, or
the TCJA, that significantly reforms the Internal Revenue Code of 1986, as amended. The TCJA, among other things, contains significant changes to corporate taxation, including reduction of the corporate tax rate from a top marginal rate of 35% to a
flat rate of 21%, limitation of the tax deduction for interest expense to 30% of adjusted earnings (except for certain small businesses), limitation of the deduction for net operating losses to 80% of current year taxable income and elimination of
net operating loss carrybacks, one time taxation of offshore earnings at reduced rates regardless of whether they are repatriated, immediate deductions for certain new investments instead of deductions for depreciation expense over time, and
modifying or repealing many business deductions and credits (including reducing the business tax credit for certain clinical testing expenses incurred in the testing of certain drugs for rare diseases or conditions generally referred to as
orphan drugs ). Our federal net operating loss carryovers will be carried forward indefinitely pursuant to the TCJA. We continue to examine the impact this tax reform legislation may have on our business. Notwithstanding the reduction in
the corporate income tax rate, the overall impact of the TCJA is uncertain and our business and financial condition could be adversely affected. The impact of this tax reform on holders of our common stock is also uncertain and could be adverse. We
urge our stockholders to consult with their legal and tax advisors with respect to such legislation and the potential tax consequences of investing in our common stock.
We are a clinical-stage biopharmaceutical company focused on transforming the lives of patients with severe and life-threatening diseases through pioneering
science and expertise. We are currently developing allogeneic, or off-the-shelf, third-party derived, antigen-specific T-cells. T-cells are a type of white blood cell that perform several important functions in a normal healthy immune system. One of these functions is to detect
and eliminate diseased cells. Cytotoxic T-cells, otherwise known as cytotoxic T lymphocytes, or CTLs, can recognize and mount an immune response against a cell expressing a disease-related
antigen in order to combat the disease. In patients with certain cancers, autoimmune conditions and viral infections, there is insufficient T-cell function to avoid or control these diseases. Our T-cell immunotherapies have the potential to restore this loss of immune function by transferring healthy, targeted T-cell immunity to patients.
Our T-cell immunotherapy product candidates are designed to precisely recognize and eliminate cancerous or
diseased cells without affecting normal, healthy cells. The technology allows for rapid delivery of a T-cellimmunotherapy product that has been manufactured in advance and stored in inventory, with each manufactured lot of cells providing
therapy for numerous potential patients. This differs from autologous, or patient-derived, treatments, in which each patient s own cells must be extracted, modified outside the body and then delivered back to the patient. We utilize a
proprietary cell selection algorithm to select the appropriate set of cells for use based on a patient s unique immune profile, and, unlike many other T-cell programs, there is no requirement for pre-treatment before our cells are administered nor is there extended monitoring following administration. For example, in our ongoing trials with our most advanced product candidate, tabelecleucel
(formerly known as ATA129), patients are monitored for two hours following receipt of tabelecleucel. Our T-cellimmunotherapy platform is applicable to a broad array of targets and diseases. With more than 200 patients treated across the
platform, we have observed clinical proof of concept across both viral and non-viral targetsin conditions ranging from liquid and solid tumors to infectious and autoimmune diseases. We have also
observed a safety profile characterized by few treatment-related serious adverse events, or SAEs, and no evidence of cytokine release syndrome to date.
Our T-cell product candidates are engineered from cells donated
by healthy individuals with normal immune function. Once cells are collected from a donor, they are bioengineered to expand those T-cells that recognize the antigen of interest. The resulting expanded T-cells are then characterized and held as inventory. From inventory, these cells can be selected, distributed and prepared for infusion in a partially human leukocyte antigen, or HLA, matched
patient in approximately 3-5 days. Following administration, our T-cells home to their target, undergo target-controlled proliferation,
eliminate diseased cells and eventually recede. Target-controlled proliferation means that our T-cells expand in number when they encounter diseased cells in a patient s body that express the
antigen the cells are designed to recognize.
We have two technology platforms. One of our technology platforms was developed from more than a decade of
groundbreaking experience at Memorial Sloan Kettering Cancer Center, or MSK. The other was developed at QIMR Berghofer Medical Research Institute, or QIMR Berghofer, in Australia. We licensed rights to certain know-how and T-cell product candidates from MSK in June 2015. Our most advanced product candidate, tabelecleucel, targets Epstein-Barr virus, or EBV. Tabelecleucel received
Breakthrough Therapy Designation, or BTD, from the U.S. Food and Drug Administration, or FDA, and Priority Medicines, or PRIME, designation from the European Medicines Agency, or EMA, and is currently being evaluated as monotherapy in two Phase 3
trials for the treatment of patients with rituximab-refractory EBV associated post-transplant lymphoproliferative disease, or EBV+PTLD. We believe that tabelecleucel has the potential to be the first commercially available off-the-shelf T-cell immunotherapy and the first FDA and EMA approved therapy for EBV+PTLD. With a European conditional marketing
authorization application planned for the first half of 2019 and U.S. biologics licensing applications planned following the completion of one of our ongoing Phase 3 trials, we are currently developing the infrastructure to commercialize
tabelecleucel globally in EBV+PTLD. We are also evaluating the potential utility of tabelecleucel in patients with other EBV associated cancers, such as nasopharyngeal carcinoma, or NPC, to continue its development in solid tumors. Additional
product candidates derived from the collaboration with MSK are being developed to treat various cancers and severe viral infections.
September 2016, we licensed rights to certain know-how and technology from QIMR Berghofer that is complementary to that which was licensed from
MSK. This know-how and technology uses targeted antigen recognition to
create off-the-shelf T-cell immunotherapy product candidates applicable to a variety of diseases,
including autoimmune conditions such as multiple sclerosis, or MS. We are working with QIMR Berghofer on the development of EBV and other virally targeted CTLs. Through this technology, we are expanding the role of immunotherapy beyond oncology and
viral infections to autoimmune disease. Our most advanced off-the-shelf T-cell product candidate
utilizing this technology, ATA188, targets select antigens of EBV and is currently being evaluated in a Phase 1 trial initially for the treatment of patients with progressive MS. In connection with the initial license from QIMR Berghofer, we
received an option to exclusively license an autologous version of ATA188, also known as ATA190, which recently demonstrated clinical activity in a Phase 1 trial in progressive MS. We expect to broadly explore the utility of our targeted antigen
recognition technology in EBV and other virally driven diseases, and additional product candidates derived from our collaboration with QIMR Berghofer are being developed.
Overall, we believe that Atara Bio is a leading allogeneic T-cell immunotherapy company with a robust and
late stage oncology pipeline and potentially transformative T-cell immunotherapies for MS and other viral associated diseases. With tabelecleucel poised to potentially become the first approved off-the-shelf T-cell therapy and a robust pipeline of high potential candidates, our ambition is to
be recognized as the leader in off-the-shelf T-cell immunotherapy.
Tabelecleucel for EBV+PTLD following HCT or SOT
Since its discovery as the first human oncovirus, EBV has been implicated in the development of a wide range of diseases, including lymphomas and other
cancers. EBV is widespread in human populations and persists as a lifelong, asymptomatic infection. In healthy individuals, a small percentage of T-cells are devoted to keeping EBV in check. In
contrast, immunocompromised patients, such as those undergoing hematopoietic cell transplants (HCT) or solid organ transplants (SOT), have a reduced ability to control EBV. Left without appropriate immune surveillance, EBV transformed cells can, in
some patients, proliferate and cause an aggressive, life-threatening cancer called EBV+PTLD. Nearly all cases of PTLD that occur following HCT are EBV positive while approximately 70% of PTLD cases that occur following SOT are EBV positive. Approximately 10-15% of PTLD patients are children. Patients with EBV+PTLD are currently treated with rituximab or rituximab plus chemotherapy when systemic treatment is indicated, with approximately 50-60% of patients either not responding to or progressing following this first line of therapy. Historical studies suggest a high unmet medical need for improved therapies in
rituximab-refractory EBV+PTLD. Median overall survival in patients with EBV+PTLD following HCT who have failed rituximab-based first line therapy is 16-56 days with a one-yearsurvival rate of
approximately 23% based on our evaluation of available historical outcomes data. One- and two-year survival following incomplete response to
rituximab in patients with high-risk EBV+PTLD after SOT is 36% and 0%, respectively. The use of chemotherapy in rituximab-refractory EBV+PTLD is frequently associated with significant rates of treatment-related mortality due to the frailty of the
patients and severe toxicities associated with chemotherapy.
We believe that the global commercial opportunity for PTLD is attractive. We expect the number of EBV+PTLD
patients to grow over time as a result of increases in the number of transplant procedures and an increasing rate of PTLD following these procedures. Based on Atara market research, we estimate that in 2019, approximately 164,000 transplant
procedures are expected to be performed in the United States, the European Union, or EU, Australia, Canada, China, Japan, South Korea and Turkey, with this number expected to increase to approximately 207,000 by 2024 due predominantly to increases
in bone marrow, peripheral blood and umbilical cord blood donation and more haploidentical transplants. Similarly, the number of cases of EBV+PTLD is expected to increase from approximately 4,700 in 2019 to 6,000 in 2024 due to the use of more
potent immuno-suppression in haploidentical transplants.
most advanced T-cell immunotherapy product candidate, tabelecleucel (previously referred to as ATA129), is an
allogeneic EBV-specific T-cell immunotherapy that is currently being investigated for the treatment of patients with rituximab-refractory
EBV+PTLD. In February 2015, the FDA granted tabelecleucel BTD in the treatment of patients with rituximab-refractory EBV+PTLD after HCT. BTD is an FDA process designed to accelerate the development and review of drugs intended to
treat a serious condition when early trials show that the drug may be substantially better than current treatment. In October 2016, tabelecleucel was accepted into the EMA Priority Medicines, or PRIME, regulatory pathway for the same indication,
providing enhanced regulatory support. In addition, tabelecleucel has received orphan status in the United States and EU for the treatment of patients with EBV+PTLD following HCT or SOT. In December 2016, we announced that we had reached
agreement with the FDA on the designs of two Phase 3 trials for tabelecleucel intended to support approval in two separate indications, the treatment of rituximab-refractory EBV+PTLD following HCT and SOT. In December 2017, following
discussion with the FDA of manufacturing and comparability data generated on material manufactured by our contract manufacturing organization, we initiated these trials in the United States. In 2018, we expect to expand these trials geographically
to include Europe, Canada, and Australia.
The Phase 3 MATCH trial (EBV+PTLD following HCT) is a multicenter, open label, single arm trial
designed to enroll approximately 35 patients with rituximab-refractory EBV+PTLD following HCT. The Phase 3 ALLELE trial (EBV+PTLD following SOT) is a multicenter, open label trial
with two non-comparative cohorts. Each cohort is designed to enroll approximately 35 patients. The first cohort will include patients who previously received rituximab monotherapy, and the
second cohort will include patients who previously received rituximab plus chemotherapy. Both cohorts are planned to enroll concurrently. The primary endpoint of both the MATCH and ALLELE trials is confirmed objective response rate, or ORR, defined
as the percent of patients achieving either a complete or partial response to treatment with tabelecleucel confirmed after the initial tumor assessment showing a response. The protocols are designed to rule out a 20% ORR as the null hypothesis. This
means that if the lower bound of the 95% confidence interval on ORR among patients receiving at least one dose of tabelecleucel exceeds 20% at the end of the study, then the trial would be expected to meet the primary endpoint for the treatment of
PTLD. For example, assuming anticipated enrollment of 35 patients in MATCH, an observed ORR above approximately 37% would be expected to meet the primary endpoint. In ALLELE, each of the two cohorts with an anticipated enrollment of 35 patients will
be analyzed separately with respect to the primary endpoint and, similarly, as an example, with 35 patients enrolled in either cohort, an observed ORR above approximately 37% would be expected to meet the primary endpoint. Secondary endpoints for
both trials include duration of response, overall survival, safety, quality of life metrics, and other measures to evaluate its health economic impact. A safety committee will meet periodically to monitor for safety. Results from the first