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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q


☒	QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended September 30, 2025


☐	TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

Commission file number 001-36548

ATARA BIOTHERAPEUTICS, INC.

(Exact Name of Registrant as Specified in its Charter)


Delaware		46-0920988
(State or Other Jurisdiction of Incorporation or Organization)		(I.R.S. Employer Identification No.)

1280 Rancho Conejo Boulevard Thousand Oaks, CA		91320
(Address of Principal Executive Offices)		(Zip Code)

Registrant’s Telephone Number, Including Area Code: (805) 623-4211

Securities registered pursuant to Section 12(b) of the Act:


Title of Each Class	Trading Symbol(s)	Name of Each Exchange on Which Registered
Common Stock, par value $0.0001 per share	ATRA	The Nasdaq Stock Market LLC

Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.


Large accelerated filer	☐	Accelerated filer	☐
Non-accelerated filer	☒	Smaller reporting company	☒
Emerging growth company	☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒

The number of outstanding shares of the Registrant’s Common Stock as of November 6, 2025 was 7,210,235 shares.

ATARA BIOTHERAPEUTICS, INC.

INDEX


		Page
PART I.	FINANCIAL INFORMATION

Item 1.	Financial Statements (Unaudited)

	Condensed Consolidated Balance Sheets	6

	Condensed Consolidated Statements of Operations and Comprehensive Income (Loss)	7

	Condensed Consolidated Statements of Changes in Stockholders’ Equity (Deficit)	8

	Condensed Consolidated Statements of Cash Flows	9

	Notes to Condensed Consolidated Financial Statements	10

Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	30

Item 3.	Quantitative and Qualitative Disclosures about Market Risk	40

Item 4.	Controls and Procedures	41

PART II.	OTHER INFORMATION	42

Item 1.	Legal Proceedings	42

Item 1A.	Risk Factors	42

Item 5.	Other Information	88

Item 6.	Exhibits	89

	Signatures	90

NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Quarterly Report on Form 10-Q contains forward-looking statements within the meaning of the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995. Such forward-looking statements, which represent our intent, belief or current expectations, involve risks and uncertainties and other factors that could cause actual results and the timing of certain events to differ materially from future results expressed or implied by such forward-looking statements. In some cases, you can identify these statements by forward-looking words such as “believe,” “may,” “will,” “estimate,” “continue,” “anticipate,” “intend,” “could,” “would,” “project,” “predict,” “plan,” “expect” or the negative or plural of these words or similar expressions. The forward-looking statements include, but are not limited to, statements about:

•

our review of strategic alternatives;

•

our expectations with regard to our programs, including client sites, the clinical studies, and reporting results of such studies;

•

the likelihood and timing of regulatory submissions or related approvals for our product candidates, including the expectations about the timing of approvals for a biologics license application (BLA) for tab-cel® for patients with Epstein-Barr virus with post-transplant lymphoproliferative disease (EBV+ PTLD);

•

the potential indications for our product and product candidates;

•

commercialization of tab-cel (Ebvallo™ in the United Kingdom (UK), the European Economic Area (EEA) and Switzerland) worldwide and our amended and restated Commercialization Agreement with Pierre Fabre Medicament, including potential milestone and royalty payments under the agreement (Ebvallo in the UK, the EEA and Switzerland subject to the Purchase and Sale Agreement with HCR Molag Fund, L.P.);

•

our Purchase and Sale Agreement and related transactions with HCR Molag Fund, L.P.;

•

our expectations regarding the potential commercial market opportunities, market size and the size of the patient populations for our product and product candidates;

•

estimates of our expenses, capital requirements and need for additional financing;

•

our expectation regarding the length of time that our existing capital resources will be sufficient to enable us to fund our planned operations, including our going concern assessment;

•

our ability to enter into favorable commercialization arrangements with third parties to commercialize our product candidates;

•

our ability to develop, acquire and advance product candidates into, and successfully complete, clinical studies;

•

the initiation, timing, costs, progress and results of clinical studies and our research and development programs;

•

our ability to enter into and maintain contracts with clinical research organizations (CROs), contract manufacturing organizations (CMOs) and other vendors for clinical studies, supplies, and other services;

•

the scope of protection we are able to obtain and maintain for the intellectual property rights covering our product and product candidates;

•

our financial performance;

•

our election to rely on reduced reporting and disclosure requirements available to smaller reporting companies;

•

developments and projections relating to our competitors and our industry;

•

our ability to have our product and product candidates manufactured for clinical studies or for commercial sale, including at commercially reasonable values;

•

the impact of public health emergencies to our business and operations, as well as the businesses and operations of third parties on which we rely;

•

the impact of our workforce reductions on our ability to attract, retain and motivate qualified personnel and on our business, operations, and financial condition; and

•

timing and costs related to the qualification of the manufacturing facilities of CMOs for commercial production.

These statements are only current predictions and are subject to known and unknown 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 sufficiency of our cash resources and need for additional capital; and other factors that may cause our or our industry’s actual results, levels of activity, performance or achievements to be materially different from those anticipated by the forward-looking statements. We discuss many of these risks in this report in greater detail under the heading “1A. Risk Factors” and elsewhere in this report. You should not rely upon forward-looking statements as predictions of future events. New risk factors and uncertainties may emerge from time to time, and it is not possible for management to predict all risks and uncertainties.

In this Quarterly Report on Form 10-Q, unless the context requires otherwise, “Atara,” “Atara Biotherapeutics,” “Company,” “we,” “our,” and “us” means Atara Biotherapeutics, Inc. and, where appropriate, its subsidiaries.

Summary Risk Factors

Our business is subject to numerous risks and uncertainties that may have a material adverse effect on our business, financial condition, or results of operations. These risks are more fully described under the heading “1A. Risk Factors” and elsewhere in this report and include, among others:

•

our activities to review and pursue strategic alternatives may not result in a strategic transaction, and even if we do consummate a strategic transaction, there is no assurance that it will deliver the benefits we expect or enhance stockholder value;

•

our board of directors may determine to pursue a liquidation and dissolution or other wind down of our business, and in such event, the amount of cash available for distribution to our stockholders, if any, will depend heavily on the timing of such liquidation as well as the amount of cash that will need to be reserved for commitments and contingent liabilities;

•

we have incurred substantial losses since our inception and anticipate that we will continue to incur substantial losses for the foreseeable future;

•

we have earned limited commercialization revenues to date, and we may never achieve profitability or we may be unable to sustain profitability on a continuing basis;

•

we will require substantial near-term financing to continue operations, and a failure to obtain this necessary capital when needed could force us to delay, limit, reduce, or terminate our product development or manufacturing efforts, or impair our exploration of strategic alternatives, or require us to pursue a liquidation and dissolution or other wind down of our business;

•

we have one approved product, Ebvallo, in the EEA, the UK, and Switzerland. We paused the development of our allogeneic CAR T cell programs and discontinued substantially all CAR T operations. If we or our collaborators are unable to successfully develop, manufacture, and commercialize our product or product candidates, or experience significant delays in doing so, our business may be materially harmed;

•

our T-cell immunotherapy product and product candidates represent new therapeutic approaches that could result in heightened regulatory scrutiny, delays in clinical development or our inability to achieve regulatory approval, or our partner's inability to achieve commercialization or secure payor coverage of our product candidates;

•

the results of preclinical studies or earlier clinical studies are not necessarily predictive of future results, and our existing product candidates may not receive regulatory approval;

•

clinical drug development involves a lengthy and expensive process with an uncertain outcome;

•

the market opportunities for our product and product candidates may be limited to those patients who are ineligible for or have failed prior treatments and may be small;

•

we may not be able to obtain or maintain orphan drug exclusivity for our product candidates;

•

the proposed revision of the European legislation on pharmaceuticals, changes in governmental administration, or changes in leadership at relevant regulatory agencies could lead to uncertainties over the regulatory framework that will be applicable to medicinal products in the EU and US, including orphan medicinal products;

•

maintaining clinical and commercial timelines is dependent on our partner's end-to-end supply chain network to support manufacturing; if they experience problems with their third party suppliers or CMOs, development and/or commercialization of our product and product candidates may be adversely affected;

•

if we are unable to obtain and maintain sufficient intellectual property protection for our product candidates, or if the scope of the intellectual property protection is not sufficiently broad, our ability to commercialize our product candidates successfully and to compete effectively may be adversely affected;

•

our principal stockholders own a significant percentage of our stock and will be able to exert control or significant influence over matters subject to stockholder approval;

•

we qualify as a “smaller reporting company” and a “non-accelerated filer,” and any decision on our part to comply only with certain reduced reporting and disclosure requirements applicable to such companies could make our stock less attractive to investors;

•

our future success depends on our ability to retain our executive officers and to attract, retain, and motivate qualified personnel; and

•

our workforce reductions may not result in anticipated savings, could result in total costs and expenses that are greater than expected, and could disrupt our business.

Atara Biotherapeutics, Inc.

Condensed Consolidated Balance Sheets

(Unaudited)

(In thousands, except per share amounts)


	September 30,			December 31,
	2025			2024
Assets
Current assets:
Cash and cash equivalents	$	5,742		$	25,030
Short-term investments		7,970			17,466
Restricted cash		—			146
Accounts receivable		1,913			1,482
Inventories		—			10,655
Other current assets		2,807			10,115
Total current assets		18,432			64,894
Property and equipment, net		147			1,294
Operating lease assets		10,707			39,807
Other assets		881			3,103
Total assets	$	30,167		$	109,098

Liabilities and stockholders’ equity (deficit)
Current liabilities:
Accounts payable	$	318		$	4,367
Accrued compensation		2,067			6,589
Accrued research and development expenses		342			7,984
Deferred revenue		1,011			95,092
Liability related to the sale of future revenues – current portion		9,670			382
Other current liabilities		4,649			20,160
Total current liabilities		18,057			134,574
Operating lease liabilities – long-term		15,005			29,914
Liability related to the sale of future revenues – long-term		31,976			38,624
Other long-term liabilities		1,763			3,269
Total liabilities		66,801			206,381

Commitments and contingencies (Note 9)

Stockholders’ equity (deficit):
Common stock—$0.0001 par value, 500,000 shares authorized as of September 30, 2025 and December 31, 2024; 7,210 and 5,859 shares issued and outstanding as of September 30, 2025 and December 31, 2024, respectively		1			1
Additional paid-in capital		1,981,822			1,957,261
Accumulated other comprehensive income (loss)		2			8
Accumulated deficit		(2,018,459	)		(2,054,553	)
Total stockholders’ equity (deficit)		(36,634	)		(97,283	)
Total liabilities and stockholders’ equity (deficit)	$	30,167		$	109,098

See accompanying notes to the condensed consolidated financial statements.

Atara Biotherapeutics, Inc.

Condensed Consolidated Statements of Operations and Comprehensive Income (Loss)

(Unaudited)

(In thousands, except per share amounts)


	Three Months Ended September 30,						Nine Months Ended September 30,
	2025			2024			2025			2024
Commercialization revenue	$	3,453		$	40,190		$	119,177		$	96,187
Costs and operating expenses:
Cost of commercialization revenue		115			7,602			21,108			14,214
Research and development expenses		2,925			43,924			37,668			122,762
General and administrative expenses		3,987			10,421			21,976			30,446
Total costs and operating expenses		7,027			61,947			80,752			167,422
Income (loss) from operations		(3,574	)		(21,757	)		38,425			(71,235	)
Other income (expense), net:
Interest income		204			459			583			1,513
Interest expense		(909	)		(1,183	)		(2,898	)		(3,598	)
Other income (expense), net		4			555			15			617
Total other income (expense), net		(701	)		(169	)		(2,300	)		(1,468	)
Income (loss) before provision for (benefit from) income taxes		(4,275	)		(21,926	)		36,125			(72,703	)
Provision for (benefit from) income taxes		28			(17	)		31			7
Net income (loss)	$	(4,303	)	$	(21,909	)	$	36,094		$	(72,710	)
Other comprehensive gain (loss):
Unrealized gain (loss) on available-for-sale securities		2			36			(6	)		226
Comprehensive income (loss)	$	(4,301	)	$	(21,873	)	$	36,088		$	(72,484	)

Basic earnings (loss) per common share	$	(0.32	)	$	(2.93	)	$	2.96		$	(11.34	)
Diluted earnings (loss) per common share	$	(0.32	)	$	(2.93	)	$	2.93		$	(11.34	)

Basic and diluted weighted-average shares outstanding		13,564			7,466			12,185			6,414
Diluted weighted-average shares outstanding		13,564			7,466			12,319			6,414

See accompanying notes to the condensed consolidated financial statements.

Atara Biotherapeutics, Inc.

Condensed Consolidated Statements of Changes in Stockholders’ Equity (Deficit)

(Unaudited)

(In thousands)


								Accumulated
	Common				Additional			Other						Total
	Stock				Paid-in			Comprehensive			Accumulated			Stockholders’
For the Nine Months Ended September 30, 2025	Shares		Amount		Capital			Income (Loss)			Deficit			Equity (Deficit)
Balance as of January 1, 2025		5,859	$	1	$	1,957,261		$	8		$	(2,054,553	)	$	(97,283	)
RSU settlements, net of shares withheld		65		—		—			—			—			—
Stock-based compensation expense		—		—		4,209			—			—			4,209
Net (loss) income		—		—		—			—			38,010			38,010
Unrealized gain (loss) on available-for-sale securities		—		—		—			(8	)		—			(8	)
Balance as of March 31, 2025		5,924	$	1	$	1,961,470		$	—		$	(2,016,543	)	$	(55,072	)
Issuance of pre-funded warrants to purchase common stock through an underwritten registered direct offering, net of offering costs of $522		834		—		14,843			—			—			14,843
RSU settlements, net of shares withheld		220		—		(1	)		—			—			(1	)
Issuance of common stock pursuant to employee stock awards		—		—		1			—			—			1
Stock-based compensation expense		—		—		2,801			—			—			2,801
Net (loss) income		—		—		—			—			2,387			2,387
Balance as of June 30, 2025		6,978	$	1	$	1,979,114		$	—		$	(2,014,156	)	$	(35,041	)
Issuance of common stock through ATM facilities, net of commissions and offering costs of $48		125			$	1,471			—			—			1,471
RSU settlements, net of shares withheld		106		—		—			—			—			—
Issuance of common stock pursuant to employee stock awards		1		—		12			—			—			12
Stock-based compensation expense		—		—		1,225			—			—			1,225
Net (loss) income		—		—		—			—			(4,303	)		(4,303	)
Unrealized gain (loss) on available-for-sale securities		—		—		—			2			—			2
Balance as of September 30, 2025		7,210	$	1	$	1,981,822		$	2		$	(2,018,459	)	$	(36,634	)


								Accumulated
	Common				Additional			Other						Total
	Stock				Paid-in			Comprehensive			Accumulated			Stockholders’
For the Nine Months Ended September 30, 2024	Shares		Amount		Capital			Income (Loss)			Deficit			Equity (Deficit)
Balance as of January 1, 2024		4,258	$	—	$	1,870,123		$	(204	)	$	(1,969,150	)	$	(99,231	)
Issuance of pre-funded warrants to purchase common stock through a registered direct offering, net of offering costs of $177		—	$	—	$	14,823		$	—		$	—		$	14,823
Issuance of common stock through ATM facilities, net of commissions and offering costs of $168		493		—		9,312			—			—			9,312
RSU settlements, net of shares withheld		63		—		(6	)		—			—			(6	)
Stock-based compensation expense		—		—		8,397			—			—			8,397
Net (loss) income		—		—		—			—			(31,752	)		(31,752	)
Unrealized gain (loss) on available-for-sale securities		—		—		—			149			—			149
Balance as of March 31, 2024		4,814	$	—	$	1,902,649		$	(55	)	$	(2,000,902	)	$	(98,308	)
RSU settlements, net of shares withheld		81		—		(1	)		—			—			(1	)
Issuance of common stock pursuant to employee stock awards		9		—		113			—			—			113
Stock-based compensation expense		—		—		6,336			—			—			6,336
Net (loss) income		—		—		—			—			(19,049	)		(19,049	)
Unrealized gain (loss) on available-for-sale securities		—		—		—			41			—			41
Balance as of June 30, 2024		4,904	$	-	$	1,909,097		$	(14	)	$	(2,019,951	)	$	(110,868	)
Issuance of common stock and pre-funded warrants to purchase common stock through a registered direct offering, net of offering costs of $220		759	$	1	$	35,779			—			—			35,780
RSU settlements, net of shares withheld		77		—		—			—			—			—
Stock-based compensation expense		—		—		6,422			—			—			6,422
Net (loss) income		—		—		—			—			(21,909	)		(21,909	)
Unrealized gain (loss) on available-for-sale securities		—		—		—			36			—			36
Balance as of September 30, 2024		5,740	$	1	$	1,951,298		$	22		$	(2,041,860	)	$	(90,539	)

See accompanying notes to the condensed consolidated financial statements.

Atara Biotherapeutics, Inc.

Condensed Consolidated Statements of Cash Flows

(Unaudited)

(In thousands)


	Nine Months Ended September 30,
	2025			2024
Operating activities
Net income (loss)	$	36,094		$	(72,710	)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Stock-based compensation expense		8,235			21,155
Depreciation and amortization expense		2,067			3,951
Accretion of liability related to sale of future revenues		2,700			3,180
Amortization (accretion) of investment premiums (discounts)		175			(30	)
Non-cash operating lease expense		4,733			9,102
Loss on impairment of lease right-of-use asset		4,130			—
Gain on derecognition of lease liabilities		(1,167	)		—
Other non-cash items, net		551			(340	)
Changes in operating assets and liabilities:
Accounts receivable		(431	)		32,773
Inventories		10,655			(4,274	)
Other current assets		5,844			(3,135	)
Other assets		42			(254	)
Accounts payable		(4,049	)		(1,537	)
Accrued compensation		(4,522	)		(3,751	)
Accrued research and development expenses		(7,642	)		(11,287	)
Other current liabilities		(3,677	)		(10,446	)
Deferred revenue		(94,081	)		1,419
Operating lease liabilities		(4,901	)		(8,062	)
Other long-term liabilities		1			—
Net cash used in operating activities		(45,243	)		(44,246	)
Investing activities
Purchases of short-term investments		(7,885	)		(19,665	)
Proceeds from maturities and sales of short-term investments		17,200			25,069
Purchases of property and equipment		—			(156	)
Proceeds from sale of property and equipment		393			—
Net cash provided by investing activities		9,708			5,248
Financing activities
Proceeds from sale of pre-funded warrants to purchase common stock in an underwritten registered direct offering or registered direct offering, net		14,843			50,813
Proceeds from issuance of common stock through ATM facilities, net		1,496			9,348
Proceeds from employee stock awards		13			113
Principal payments on finance lease obligations		(250	)		(657	)
Other financing activities, net		(1	)		(7	)
Net cash provided by financing activities		16,101			59,610
Increase (decrease) in cash, cash equivalents and restricted cash		(19,434	)		20,612
Cash, cash equivalents and restricted cash at beginning of period		25,176			25,987
Cash, cash equivalents and restricted cash at end of period	$	5,742		$	46,599
Non-cash financing activities
Accrued costs related to underwritten registered direct offering	$	—		$	210
Accrued costs related to ATM facility	$	25		$	—

Supplemental cash flow disclosure
Cash paid for interest	$	171		$	497
Cash paid for income taxes	$	31		$	24

See accompanying notes to the condensed consolidated financial statements.

Atara Biotherapeutics, Inc.

Notes to Condensed Consolidated Financial Statements

(Unaudited)

Description of Business

Atara Biotherapeutics, Inc. (Atara, we, our or the Company) was incorporated in August 2012 in Delaware. Atara is 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 disease.

Our most advanced T-cell immunotherapy program, tab-cel® (tabelecleucel), has received marketing authorization approval under the proprietary name Ebvallo™ by the European Commission (EC) for commercial sale and use in the European Economic Area (EEA), by the Medicines and Healthcare products Regulatory Agency (MHRA) for commercial sale and use in the United Kingdom (UK) and by Swissmedic for commercial sale and use in Switzerland. Tab-cel is currently in Phase 3 development in the US. In October 2021, we entered into a commercialization agreement (Pierre Fabre Commercialization Agreement) with Pierre Fabre Medicament (Pierre Fabre), as amended in September 2022, pursuant to which we granted to Pierre Fabre an exclusive, field-limited license to commercialize and distribute Ebvallo in Europe and select emerging markets in the Middle East, Africa, Eastern Europe and Central Asia (the Initial Territory), following regulatory approval. In December 2022, we sold a portion of our right to receive royalties and certain milestones in Ebvallo under the Pierre Fabre Commercialization Agreement to HCR Molag Fund L.P. (HCRx) for a total investment amount of $31.0 million, subject to a repayment cap between 185% and 250% of the total investment amount by HCRx. See Note 6 for further information.

In October 2023, we amended and restated the Pierre Fabre Commercialization Agreement (A&R Commercialization Agreement). Pursuant to the A&R Commercialization Agreement, Pierre Fabre’s exclusive rights to research, develop, manufacture, commercialize and distribute tab-cel (Ebvallo) were expanded to include all other countries in the world (Additional Territory) in addition to the Initial Territory (Initial Territory and Additional Territory together, the Territory), subject to our performance of certain obligations. See Note 5 for further information. In March 2025, we completed the transfer of all manufacturing responsibility to Pierre Fabre and Pierre Fabre is, at its cost, responsible for manufacturing and supplying tabelecleucel for development and commercialization worldwide under an amendment to the A&R Commercialization Agreement (A&R Commercialization Agreement Amendment). Pursuant to the A&R Commercialization Agreement Amendment, Pierre Fabre also agreed to assume the future costs related to remediation of the third-party manufacturing facility to address the FDA's requests to support resubmission of the BLA for tab-cel. In exchange for accelerating the transfer of all manufacturing responsibility and assumption of such remediation costs by Pierre Fabre, among other things, we agreed to reduce the amount of certain potential future regulatory and commercial milestone payments under the A&R Commercialization Agreement. In July 2025, we further amended the A&R Commercialization Agreement and completed the transfer of all clinical (including sponsorship of the ALLELE and tab-cel multi-cohort studies) and development responsibility for tab-cel to Pierre Fabre. Pierre Fabre is, at its cost, responsible for all clinical (including sponsorship of the ALLELE and tab-cel multi-cohort studies) and development activities (other than responsibility for regulatory activities) for tabelecleucel worldwide. In October 2025, we further amended the A&R Commercialization Agreement to transfer all regulatory activities (including sponsorship of the tab-cel BLA) to Pierre Fabre. Pierre Fabre is, at its cost, responsible for all regulatory activities (including sponsorship of the tab-cel BLA) for tab-cel worldwide, and Pierre Fabre is to use commercially reasonable efforts to obtain BLA approval as soon as possible. We will, at Pierre Fabre’s expense, continue to observe the regulatory activities and support Pierre Fabre in its efforts to obtain BLA approval. We believe the tab-cel BLA is on track with a Prescription Drug User Fee Act target action date of January 10, 2026.

We have licensed rights to T-cell product candidates from Memorial Sloan Kettering Cancer Center (MSK), rights related to our next-generation CAR T programs from MSK, and rights to know-how and technology from the Council of the Queensland Institute of Medical Research (QIMR Berghofer). In May 2025, we returned the rights to the ATA188 and EBV Vaccine programs to QIMR. See Note 9 for further information.

We have executed various strategic reductions in force over the past several years. In November 2023, we announced a reduction in force that reduced our workforce at that time by approximately 30%. We recognized $6.7 million in total for severance and related benefits for employees laid off under the reduction in force. These charges are one-time termination benefits and are all cash charges.

In January 2024, we announced a reduction in workforce at that time of approximately 25%. We recognized $5.1 million in total for severance and related benefits for employees laid off under the reduction in force. The majority of the associated costs are cash expenditures and primarily one-time termination benefits.

In January 2025, we announced a reduction in force of approximately 50% of our total workforce at that time. The workforce reduction included total restructuring charges of $7.1 million, comprised primarily of severance payments and wages for the 60-day notice period in accordance with the California WARN Act. In March 2025, we announced a further reduction in force of approximately 50% of our total workforce at that time. The workforce reduction included total restructuring charges of $2.7 million, comprised primarily of severance payments and wages for the 60-day notice period in accordance with the California WARN Act. In May 2025, we announced a further reduction in force of approximately 30% of our total workforce at that time, retaining approximately 23 employees essential to execute our strategic priorities. The workforce reduction included total restructuring charges of $1.4 million, comprised primarily of severance payments and wages for the 60-day notice period in accordance with the California WARN Act. Refer to Note 8 for further information.

Summary of Significant Accounting Policies

Basis of Presentation

The accompanying unaudited interim condensed consolidated financial statements include the accounts of Atara and its wholly owned subsidiaries and have been prepared in accordance with U.S. generally accepted accounting principles (U.S. GAAP) and the requirements of the Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP can be condensed or omitted. These unaudited interim condensed consolidated financial statements should therefore be read in conjunction with the audited consolidated financial statements and notes for the year ended December 31, 2024, included in the Company’s Annual Report on Form 10-K filed with the SEC on March 7, 2025. In the opinion of management, the condensed consolidated financial statements reflect all adjustments, consisting only of normal recurring adjustments, which are necessary for a fair presentation of the Company’s condensed consolidated financial statements. The results of operations for any interim period are not necessarily indicative of the results to be expected for the full year or any other future period. The condensed consolidated balance sheet as of December 31, 2024 has been derived from audited consolidated financial statements at that date but does not include all of the information required by U.S. GAAP for complete consolidated financial statements.

June 2024 Reverse Stock Split

At our annual meeting of stockholders held on June 10, 2024, our stockholders approved a proposal to authorize our Board of Directors (Board) to amend our Amended and Restated Certificate of Incorporation to effect a reverse stock split. The Board approved the reverse stock split on June 10, 2024 and, on June 20, 2024, we effected a 1-for-25 reverse stock split of our common stock. The par value and the authorized shares of the common stock were not adjusted as a result of the reverse stock split. All equity related information including per share amounts for all periods presented in these condensed consolidated financial statements and the notes thereto have been adjusted retroactively, where applicable, to reflect the effect of this reverse stock split.

Liquidity Risk

We have incurred significant operating losses since inception and have relied primarily on public and private equity financings and receipts from commercialization and license and collaboration agreements to fund our operations. As we continue to incur losses, our transition to profitability will depend on the successful development, approval and commercialization of product candidates and on the achievement of sufficient revenues to support our cost structure. We may never achieve sustained operating cash inflows or profitability.

Going Concern

With the exception of the first nine months of 2025, we have incurred substantial operating losses since inception, and we expect that existing cash, cash equivalents and short-term investments as of September 30, 2025, will not be sufficient to fund our planned operations for at least 12 months from the date of issuance of these condensed consolidated financial statements. Although we anticipate the receipt of certain payments from the amended and restated Pierre Fabre Commercialization Agreement, such payments are contingent upon the approval of the tab-cel BLA, as well as the completion of specific regulatory activities by us, our partner and actions taken by third parties, and are, therefore, uncertain at this time.

In order to alleviate the conditions that raise substantial doubt about our ability to continue as a going concern, we plan to secure additional capital, potentially through a combination of public or private security offerings; use of our ATM facility as described in Note 10; issuance of debt; and/or execution of strategic transactions. We may need to raise additional funding as required based on the status of our development programs and our projected cash flows. Even though we have been successful in raising capital in the past, and expect to continue to raise capital as required, there is no assurance that we will be successful in obtaining sufficient funding on terms acceptable to us to fund continuing operations, if at all, or identify and enter into any

strategic transactions that will provide the capital that we will require. If we are unable to obtain sufficient funding on acceptable terms, we could be forced to delay, limit, reduce or terminate ongoing activities for our product candidate, which could have a material adverse effect on our business, results of operations, and financial condition. Accordingly, we have concluded that substantial doubt exists with respect to our ability to continue as a going concern for at least 12 months after the issuance of the accompanying condensed consolidated financial statements. The condensed consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty.

Segment and Geographic Information

We operate and manage our business as one operating and reportable segment, which is the business of developing therapeutics. Our President & Chief Executive Officer, who is our chief operating decision maker (CODM), reviews financial information on an aggregate basis for purposes of allocating resources and evaluating financial performance. The CODM assesses performance for the business and decides how to allocate resources based on net income (loss) that also is reported on the income statement as consolidated net income (loss). The CODM uses net income (loss) to monitor expenditures and budget versus actual results. The measure of segment assets is reported on the balance sheet as total consolidated assets. The following tables represent information provided to the chief operating decision maker:


	Three Months Ended September 30,						Nine Months Ended September 30,
	2025			2024			2025		2024
Revenue	$	3,453		$	40,190		$	119,177	$	96,187
Less:
Cost of commercialization revenue		115			7,602			21,108		14,214
Technical operations and quality expenses		1,669			30,037			23,479		79,075
Medical and safety expenses		299			9,446			9,262		31,274
Regulatory expenses		957			4,441			4,927		12,413
General and administrative expenses		3,987			10,421			21,976		30,446
Other segment items*		729			152			2,331		1,475
Net income (loss)		(4,303	)		(21,909	)		36,094		(72,710	)

* Other segment items include Other Income (expense), net and Provision for (benefit from) income taxes

Substantially all of our assets are located in the U.S. All commercialization revenue recognized in the three and nine months ended September 30, 2025 and 2024 related to our agreements with Pierre Fabre, a French company.

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates, assumptions and judgments that affect the amounts reported in the financial statements and accompanying notes. Significant estimates relied upon in preparing these financial statements include estimates related to revenue recognition, accrued research and development expenses, stock-based compensation expense, income taxes and the liability related to the sale of future revenues. Actual results could differ materially from those estimates.

Recent Accounting Pronouncements

We consider the applicability and impact of any recent Accounting Standards Update (ASU) issued by the Financial Accounting Standards Board (FASB). Other than the ASUs listed below, all other ASUs were assessed and determined to be either not applicable to Atara or are expected to have minimal impact on our condensed consolidated financial statements.

In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740) - Improvements to Income Tax Disclosures. This ASU enhances income tax disclosures by requiring, among other things, a tabular reconciliation of the effective tax rate with standardized categories and disclosure of percentage and dollar amounts for significant items, and annual disclosure of income taxes paid by jurisdiction, with a breakdown for significant individual jurisdictions. It also requires disaggregation of income and related tax expense by domestic and foreign components and eliminates certain existing disclosures. ASU 2023-09 is effective for annual periods beginning after December 15, 2024. Early adoption is permitted. We are currently assessing the potential impact of the ASU on our disclosures.

In November 2024, the FASB issued ASU No. 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40), which requires disclosure of additional information about specific expense categories underlying certain income statement expense line items. This ASU is effective for our annual periods beginning after December 15, 2026, and requires either prospective or retrospective application. We are currently evaluating the impact of the ASU on our disclosures.

Net Income (Loss) per Common Share

Basic net income (loss) per common share is calculated by dividing net income (loss) by the weighted-average number of shares of common stock and pre-funded warrants outstanding during the period, without consideration of common share equivalents. Diluted net income (loss) per common share is computed by dividing net income (loss) by the weighted-average number of shares of common stock, pre-funded warrants and common share equivalents outstanding for the period. The pre-funded warrants are included in the computation of basic and diluted net income (loss) per common share as the exercise price is negligible and the pre-funded warrants are fully vested and exercisable. Common share equivalents are only included in the calculation of diluted net income (loss) per common share when their effect is dilutive.

The following table is a reconciliation of the share amounts used in computing earnings per share:


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
	(in thousands)				(in thousands)
Weighted average shares outstanding – Basic		13,564		7,466		12,185		6,414
Effect of dilutive securities		—		—		134		—
Weighted average shares outstanding – Diluted		13,564		7,466		12,319		6,414

Potential dilutive securities, which include unvested restricted stock units (RSUs), unvested performance-based RSUs and performance-based options to purchase common stock for which established performance criteria have been achieved as of the end of the respective periods, vested and unvested options to purchase common stock and shares to be issued under our employee stock purchase plan (ESPP), have been excluded from the computation of diluted net earnings (loss) per common share as the effect is antidilutive. Therefore, the denominator used to calculate both basic and diluted net earnings (loss) per common share is the same in all periods for which we record a net loss.

The following table represents the potential common shares issuable pursuant to outstanding securities as of the related period end dates that were excluded from the computation of diluted net income (loss) per common share, as their inclusion would have an antidilutive effect:



	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Unvested RSUs		10,578		495,996		31,221		495,996
Vested and unvested options		142,338		263,788		142,338		263,788
ESPP share purchase rights		5,763		34,511		5,763		34,511
Total		158,679		794,295		179,322		794,295

Financial Instruments

Our financial assets are measured at fair value on a recurring basis using the following hierarchy to prioritize valuation inputs, in accordance with applicable U.S. GAAP:

Level 1: Quoted prices in active markets for identical assets or liabilities that we have the ability to access.

Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data such as quoted prices, interest rates and yield curves.

Level 3: Inputs that are unobservable data points that are not corroborated by market data.

We review the fair value hierarchy classification on a quarterly basis. Changes in the ability to observe valuation inputs may result in a reclassification of levels of certain securities within the fair value hierarchy. We recognize transfers into and out of levels within the fair value hierarchy in the period in which the actual event or change in circumstances that caused the transfer occurs. There have been no transfers between Level 1, Level 2 and Level 3 in any periods presented.

Financial assets and liabilities are considered Level 2 when their fair values are determined using inputs that are observable in the market or can be derived principally from or corroborated by observable market data such as pricing for similar securities, recently executed transactions, cash flow models with yield curves, and benchmark securities. In addition, Level 2 financial instruments are valued using comparisons to like-kind financial instruments and models that use readily observable market data as their basis. U.S. Treasury, government agency and corporate debt obligations, commercial paper and asset-backed securities are valued primarily using market prices of comparable securities, bid/ask quotes, interest rate yields and prepayment spreads and are included in Level 2.

Financial assets and liabilities are considered Level 3 when their fair values are determined using pricing models, discounted cash flow methodologies, or similar techniques, and at least one significant model assumption or input is unobservable. We have no Level 3 financial assets or liabilities.

The following tables summarize the estimated fair value and related valuation input hierarchy of our available-for-sale securities as of each period end:


		Total			Total			Total		Total
		Amortized			Unrealized			Unrealized		Estimated
As of September 30, 2025:	Input Level	Cost			Gain			Loss		Fair Value
		(in thousands)
Money market funds	Level 1	$	4,072		$	—		$	—	$	4,072
U.S. Treasury obligations	Level 2	$	7,969		$	1		$	—	$	7,970
Total available-for-sale securities			12,041			1			—	$	12,042
Less: amounts classified as cash equivalents			(4,072	)		—			—	$	(4,072	)
Amounts classified as short-term investments		$	7,969		$	1		$	—	$	7,970

		Total			Total			Total		Total
		Amortized			Unrealized			Unrealized		Estimated
As of December 31, 2024:	Input Level	Cost			Gain			Loss		Fair Value
		(in thousands)
Money market funds	Level 1	$	13,718		$	—		$	—	$	13,718
U.S. Treasury obligations	Level 2		27,450			8			—		27,458
Total available-for-sale securities			41,168			8			—		41,176
Less: amounts classified as cash equivalents			(23,708	)		(2	)		—		(23,710	)
Amounts classified as short-term investments		$	17,460		$	6		$	—	$	17,466

The amortized cost and fair value of our available-for-sale securities by contractual maturity were as follows:


	As of September 30, 2025				As of December 31, 2024
	Amortized		Estimated		Amortized		Estimated
	Cost		Fair Value		Cost		Fair Value
	(in thousands)				(in thousands)
Maturing within one year	$	12,041	$	12,042	$	41,168	$	41,176
Maturing in one to five years		—		—		—		—
Total available-for-sale securities	$	12,041	$	12,042	$	41,168	$	41,176

We considered the current and expected future global economic and market conditions, including, but not limited to, the wars in Ukraine and the Middle East and increased tensions between the U.S. and China, and determined that our investments have not been significantly impacted. As of September 30, 2025, no significant facts or circumstances were present to indicate a deterioration in the creditworthiness of the issuers of the available-for-sale securities we hold, and we have no requirement or intention to sell these securities before maturity or recovery of their amortized cost basis. For all securities with a fair value less than its amortized cost basis, we determined the decline in fair value below amortized cost basis to be non-credit related and no allowance for losses has been recorded. During the nine months ended September 30, 2025 and 2024, we did not recognize any impairment losses on our investments.

We have elected the practical expedient to exclude the applicable accrued interest from both the fair value and the amortized cost basis of our available-for-sale securities for purposes of identifying and measuring an impairment. We present accrued interest receivable related to our available-for-sale securities in other current assets, separate from short-term investments, on our condensed consolidated balance sheet. As of September 30, 2025 and December 31, 2024, accrued interest receivable was immaterial. We have not written off any accrued interest receivables during the nine months ended September 30, 2025 and 2024.

In addition, restricted cash collateralized by a certificate of deposit is a financial asset measured at fair value and is a Level 1 financial instrument under the fair value hierarchy.

The following table provides a reconciliation of cash, cash equivalents and restricted cash within the condensed consolidated balance sheets that sum to the total of the same such amounts in the condensed consolidated statement of cash flows:


	September 30,		December 31,
	2025		2024
	(in thousands)
Cash and cash equivalents	$	5,742	$	25,030
Restricted cash – short term		—		146
Total cash, cash equivalents and restricted cash	$	5,742	$	25,176

Out-license Agreements

Pierre Fabre Agreements

In October 2021, we entered into the Pierre Fabre Commercialization Agreement, pursuant to which, we granted to Pierre Fabre an exclusive, field-limited license to commercialize and distribute Ebvallo in Europe and select emerging markets in the Initial Territory following regulatory approval. In September 2022, we entered into Amendment No. 1 to the Pierre Fabre Commercialization Agreement (PF Amendment No. 1). Under the terms of PF Amendment No. 1, following European Commission approval of Ebvallo for EBV+ PTLD and subsequent filing of the Marketing Authorization Application (MAA) transfer to Pierre Fabre, we received an additional $30 million milestone payment in exchange for, among other things, a reduction in: (i) royalties we are eligible to receive as a percentage of net sales of tab-cel (Ebvallo) in the Territory, and (ii) the supply price mark up on tab-cel purchased by Pierre Fabre. Additionally, we agreed to extend the time period for provision of certain services to Pierre Fabre in the Initial Territory at our cost pursuant to the Pierre Fabre Commercialization Agreement. In December 2022, we sold a portion of our right to receive royalties and certain milestone payments related to Ebvallo in the Initial Territory under the Pierre Fabre Commercialization Agreement to HCRx for a total investment amount of $31.0 million, subject to a repayment cap between 185% and 250% of the total investment amount by HCRx. See Note 6 for further information related to the agreement with HCRx.

In October 2023, we entered into the A&R Commercialization Agreement with Pierre Fabre. Pursuant to the A&R Commercialization Agreement, Pierre Fabre’s exclusive rights to research, develop, manufacture, commercialize and distribute tab-cel were expanded to include all other countries in the world (Additional Territory) in addition to the Initial Territory (together, the Territory), subject to our performance of certain obligations as described below.

In August 2024, we sold certain intermediates used in the manufacture of Ebvallo to Pierre Fabre for $15.5 million, transferring title and risk of loss to these intermediates in advance of the Manufacturing Transition Date (as defined below), which guarantees Pierre Fabre supply and control of intermediates to be used in the production of Ebvallo. We received payment for these intermediates in September 2024.

We also entered into a separate manufacturing and supply agreement with Pierre Fabre for us to manufacture Ebvallo for Pierre Fabre to use in the Initial Territory based on a fixed price through December 31, 2023 and at a price equal to cost plus a margin for orders placed after December 31, 2023, subject to a maximum annual increase. In March 2025, we completed the transfer of all manufacturing responsibility to Pierre Fabre and Pierre Fabre is, at its cost, responsible for manufacturing and supplying tabelecleucel for development and commercialization worldwide under an amendment to the A&R Commercialization Agreement (A&R Commercialization Agreement Amendment). The A&R Commercialization Agreement Amendment defined the Manufacturing Transition Date as March 31, 2025 (the Manufacturing Transition Date). At the Manufacturing Transition Date, we sold to Pierre Fabre certain unreleased batches and intermediate inventory used in the production of tab-cel. We also sold to Pierre Fabre certain materials that support tab-cel manufacturing at no cost. Pursuant to the A&R Commercialization Agreement Amendment, Pierre Fabre has also agreed to pay certain liabilities owed to our CMOs that were incurred as of December 31, 2024. In exchange for accelerating the transfer of all manufacturing responsibility and assumption of such costs by Pierre Fabre, among other things, we agreed to reduce the amount of certain potential future regulatory and commercial milestone payments under the A&R Commercialization Agreement.

Cell selection is the process of identifying the appropriate cell line from available tab-cel inventory to be used for a patient. In February 2025, we transferred commercial cell selection in the Initial Territory and the Additional Territory to Pierre Fabre. Prior to the transfer of commercial cell selection, we were responsible for the performance of commercial cell selection services in the Initial Territory at our cost, and we were responsible for the performance of commercial cell selection services in the Additional Territory at the sole expense of Pierre Fabre. Without transfer of the cell selection technology, no other party can provide such services. In July 2025, we transferred clinical cell selection to Pierre Fabre.

Pierre Fabre paid us an upfront cash payment of $45.0 million for the exclusive license grant for the Initial Territory in the fourth quarter of 2021. In December 2022, we met the contractual right to receive $40.0 million in milestone payments upon certain regulatory milestones, for which the cash was received in January 2023. Subject to the terms of the royalty purchase agreement with HCRx, as described in Note 6, we are entitled to receive an aggregate of up to $308.0 million in remaining milestone payments upon achieving certain regulatory and commercial milestones in addition to double-digit tiered royalties as a percentage of net sales of Ebvallo in the Initial Territory, until the later of 12 years after the first commercial sale in each such country, the expiration of specified patent rights, or the expiration of all regulatory exclusivity for Ebvallo on a country-by-country basis. In December 2023, upon the effective date of the A&R Commercialization Agreement, we met the contractual right to receive an additional upfront cash payment of $20.0 million for the expanded exclusive license grant in the Additional Territory, for which the cash was received in January 2024. In March 2024, we met the contractual right to receive $20.0 million in milestone payments upon achieving a regulatory milestone, for which the cash was received in April 2024. In July 2024, we met the contractual right to receive an additional $20.0 million in milestone payments upon achieving acceptance of our biologics license application (BLA) for tab-cel by the United States Food and Drug Administration (FDA) and we received the cash in August 2024. We will also be entitled to receive an aggregate of up to $550.0 million in additional payments upon achieving certain regulatory and commercial milestones relating to tab-cel in the Additional Territory, including up to $40.0 million in potential regulatory milestones in connection with the approval by the FDA of a BLA for tab-cel under the terms of the A&R Commercialization Agreement, as amended by the A&R Commercialization Agreement Amendment. We will be eligible to receive double-digit tiered royalties as a percentage of net sales of tab-cel in the Additional Territory until the later of 12 years after the first commercial sale in each such country, the expiration of specified patent rights in each such country, or the expiration of all regulatory exclusivity for tab-cel on a country-by-country basis.

As part of the Pierre Fabre Commercialization Agreement, we formed a joint steering committee (JSC) with Pierre Fabre that provides oversight, decision making and implementation guidance regarding the commercialization activities, the responsibilities of which has been expanded to cover the incremental scope of the A&R Commercialization Agreement.

During the applicable period specified in the A&R Commercialization Agreement, we are responsible for various development, safety, process science, and regulatory activities, including obtaining regulatory approval in the United States for tab-cel for EBV-associated post-transplant lymphoproliferative disease. Pierre Fabre will pay us for these services in accordance with the A&R Commercialization Agreement. Pierre Fabre is responsible, at its cost, for obtaining and maintaining all other required regulatory approvals and for commercialization and distribution of tab-cel in the Additional Territory, including conducting any other clinical study required. We will own any intellectual property rights developed solely by us under the A&R Commercialization Agreement. As described above, in March 2025, we transferred all process science services and manufacturing responsibilities to Pierre Fabre. In July 2025, we further amended the A&R Commercialization Agreement and completed the transfer of all development, clinical (including sponsorship of the ALLELE and tab-cel multi-cohort study) and safety activities for tab-cel to Pierre Fabre.

Accounting Analysis

Identification of the Contract

We assessed this arrangement in accordance with ASC 606 and concluded that the promises in the A&R Commercialization Agreement represent transactions with a customer.

Identification of the Promises and Performance Obligations

We identified five performance obligations under the A&R Commercialization Agreement, as amended by the A&R Commercialization Agreement Amendment, consisting of the following material promises:

(1)

the transfer of intellectual property rights in the form of a license in the Initial Territory, the obligation to participate in the JSC, the manufacture and supply of Ebvallo, a material right for purchases associated with the manufacture and supply of Ebvallo, and the performance of cell-selection services. We concluded that the individual promises are not distinct because Pierre Fabre cannot benefit from the license without the other services and vice versa, since Pierre Fabre is not capable of carrying out the manufacturing and supply and cell selection services on their own, until the transfer of the related technologies occur. Consequently, these promises represent a single performance obligation, collectively referred to as the Initial Territory Obligation.

(2)

the transfer of intellectual property rights in the form of a license in the Additional Territory, the manufacture and supply of tab-cel and the performance of cell-selection services, as well as the promises to transfer the related technologies, and perform certain development, safety, regulatory and information technology transition services. We concluded that the promises are not distinct because Pierre Fabre cannot benefit from the license without the

other services and vice versa. Consequently, these promises represent a single performance obligation, collectively referred to as the Additional Territory Obligation.

(3)

performance of certain process science services, referred to as the Process Sciences Obligation.

(4)

the sale of certain intermediate inventory used in the production of tab-cel in existence on the Manufacturing Transition Date, referred to as the Intermediate Inventory Obligation; and

(5)

the sale of certain materials to support the production of tab-cel in existence on the Manufacturing Transition Date, referred to as the Manufacturing Materials Obligation.

Determination of the Transaction Price

Under the Pierre Fabre Commercialization Agreement, we determined that the $45.0 million upfront payment constituted the entire consideration to be included in the transaction price at the outset of the arrangement, and the $40.0 million in regulatory milestones achieved in December 2022 were added to the transaction price upon meeting the related milestone criteria. The remaining potential regulatory and commercial milestone payments that we are eligible to receive were excluded from the transaction price, as the milestone amounts were fully constrained based on the probability of achievement or have not been earned. None of the future royalty and sales-based milestone payments were included in the transaction price, as the potential payments represent sales-based consideration.

Upon the effective date of the A&R Commercialization Agreement, the $20.0 million additional upfront payment received and estimated revenue for the development, safety, regulatory and process science services were added to the transaction price, and the $20.0 million regulatory milestone achieved in March 2024 and the $20.0 million regulatory milestone achieved in July 2024 were added to the transaction price upon meeting the related milestone criteria. The remaining potential regulatory and commercial milestone payments that we are eligible to receive were excluded from the transaction price, as the milestone amounts were fully constrained based on the probability of achievement or have not been earned. None of the future royalty and sales-based milestone payments were included in the transaction price, as the potential payments represent sales-based consideration. Upon the effective date of the A&R Commercialization Agreement Amendment, the liabilities owed to the CMOs that were relieved by Pierre Fabre were added to the transaction price.

We reevaluate the transaction price at the end of each reporting period and as uncertain events are resolved or other changes in circumstances occur, and, as necessary, we adjust our estimate of the transaction price.

Allocation of the Transaction Price to Performance Obligations

The transaction price was allocated to each performance obligation based on their relative standalone selling price. We developed the estimated standalone selling price for each of the A&R Commercialization Agreement performance obligations with the objective of determining the price at which we would sell such an item if it were to be sold regularly on a standalone basis.

Recognition of Revenue

Commercialization revenue associated with the Initial Territory Obligation was recognized over the period during which the material right existed, which ended on March 31, 2025, the Manufacturing Transition Date. Commercialization revenue associated with sales of Ebvallo and intermediate inventory to Pierre Fabre was deferred until we performed the associated manufacturing of finished Ebvallo product inventory and cell selection services, or until the transfer of manufacturing and cell selection technology to Pierre Fabre. All revenue associated with the Initial Territory Obligation was recognized as of March 31, 2025. As of March 31, 2025, Pierre Fabre is able to utilize the inventory it had purchased from us on its own.

Commercialization revenue associated with the Additional Territory Obligation and the Process Sciences Obligation is recognized using a cost-based input method based on the amount of actual costs incurred relative to the total budgeted costs expected to be incurred for the respective performance obligations. A cost-based input method of revenue recognition requires us to make estimates of costs to complete our performance obligation. In making such estimates, significant judgment is required to evaluate assumptions related to cost estimates. The cumulative effect of revisions to estimated costs to complete our performance obligation will be recorded in the period in which changes are identified and amounts can be reasonably estimated. The Process Services Obligation was completed on the Manufacturing Transition Date. All revenue associated with the Process Sciences Obligation was recognized as of March 31, 2025. As of September 30, 2025, there is approximately $1 million of deferred revenue remaining associated with the Additional Territory Obligation to be recognized upon completion of certain regulatory obligations. The transfer of control occurs over the respective time period and, in our judgment, is the best measure of progress towards satisfying the performance obligation. A significant change in these assumptions and estimates could have

a material impact on the timing and amount of revenue recognized in future periods. We recognized all revenue associated with the Intermediate Inventory Obligation and the Manufacturing Materials Obligation at a point in time, upon the Manufacturing Transition Date, which is when title and risk of loss, and thus, control, of the intermediate inventory and materials transferred to Pierre Fabre.

Deferred revenue activity related to commercialization revenue for the nine months ended September 30, 2025 was as follows:


	(in thousands)
Deferred revenue, January 1, 2025	$	95,092
Additions		22,811
Recognized into commercialization revenue		(116,892	)
Deferred revenue September 30, 2025		1,011
Less: deferred revenue – current portion		(1,011	)
Deferred revenue – long-term, September 30, 2025	$	—

During the nine months ended September 30, 2025, we recognized $91.1 million of revenue that was included in the deferred revenue balance as of December 31, 2024.

Costs incurred relating to performing the services within the Additional Territory Obligation and Process Sciences Obligation consist of third party expenses and time incurred by our employees to satisfy requirements set forth by the A&R Commercialization Agreement. These costs are included in research and development expenses in the condensed consolidated statements of operations and comprehensive income (loss). Such costs were $0.9 million and $12.0 million for the three and nine months ended September 30, 2025, respectively, and such costs were $11.1 million and $33.8 million for the three and nine months ended September 30, 2024, respectively.

Liability Related to the Sale of Future Revenues

In December 2022, we entered into a Purchase and Sale Agreement (HCRx Agreement) with HCR Molag Fund, L.P., a Delaware limited partnership, (HCRx). In exchange for a payment of $31.0 million (Investment Amount) to Atara, net of certain transaction expenses, HCRx obtained the right to receive certain Ebvallo royalties and milestone payments payable by Pierre Fabre under the Pierre Fabre Commercialization Agreement up to an agreed upon multiple of the Investment Amount.

Under the HCRx Agreement, HCRx is entitled to receive tiered royalties on net sales of Ebvallo in the Initial Territory in amounts ranging from the mid-single digits to double digits based on annual net sales. HCRx is also entitled to certain milestone payments due to Atara from Pierre Fabre. The total royalties and milestones payable to HCRx are capped between 185% and 250% of the Investment Amount, depending upon the timing of such royalties and milestones. Upon meeting the cap amount, HCRx’s right to receive royalties and milestone payments will terminate and all rights will revert to Atara. To the extent a certain milestone within the Pierre Fabre Commercialization Agreement is not achieved on or prior to June 30, 2026, we will be required to make a one-time cash payment in the amount of $9.0 million to HCRx, and HCRx shall transfer all of its right, title and interest in this certain $9.0 million milestone payment to Atara. This payment, if required, would be included in the calculation of aggregate payments made to HCRx.

The gross proceeds of the Investment Amount of $31.0 million were recorded as a liability related to the sale of future revenues, net of transaction costs of $0.4 million, and is amortized using the effective interest method over the life of the arrangement.

To determine the amortization of the recorded liability, we are required to estimate the total amount of future payments to be received by HCRx. The sum of these amounts less the $31.0 million proceeds we received will be recorded as interest expense over the life of the HCRx Agreement. We estimate the effective interest rate used to record non-cash interest expense under the HCRx Agreement based on the estimate of future royalty payments to be received by HCRx. On September 30, 2025, the annual effective interest rate was approximately 9%. Over the life of the arrangement, the actual effective interest rate will be affected by the amount and timing of the actual and forecasted royalty and milestone payments to HCRx. At each reporting date, we will reassess our estimate of the timing and amounts of future payments made to HCRx, and prospectively adjust the effective interest rate and amortization of the liability as necessary.

The following table presents the changes in the liability related to the sale of future revenues under the HCRx Agreement for the nine months ended September 30, 2025:


	(in thousands)
Liability related to sale of future revenues as of January 1, 2025	$	39,006
Accretion of interest expense on liability related to sale of future revenues		2,700
Amortization of debt discount and debt issuance costs		44
Repayment of the liability		(104	)
Liability related to the sale of future revenues as of September 30, 2025		41,646
Less: Liability related to the sale of future revenues - current portion		(9,670	)
Liability related to sale of future revenues - long-term	$	31,976

Leases

In November 2018, we entered into a lease agreement for office space in Thousand Oaks, California, that expires in February 2026 and for which we have the option to extend the lease for an additional period of five years after the initial term. In February 2025, we vacated this office space prior to the termination of the lease, resulting in the right-of-use asset to be abandoned. When a lease right-of-use asset has been abandoned, the estimated useful life of the asset is updated to reflect the cease use date, and the remaining carrying value of the asset is amortized ratably over the period between the commitment date and the cease use date. In February 2025, with the abandonment of the lease, we recognized an acceleration of amortization expense on the abandoned right-of-use asset in the amount of $1.0 million within general and administrative expenses on the accompanying condensed consolidated statements of operations and comprehensive income (loss) for the nine months ended September 30, 2025. The lease liability for the Thousand Oaks office remains on our balance sheet.

In March 2021, we entered into a lease agreement for the 33,659 square feet of office, lab and warehouse space at the Atara Research Center (ARC). During the third quarter of 2021, the initial 10.5-year lease term commenced, upon substantial completion of the landlord’s work as defined under the agreement. Base rent is subject to annual increases of 3% with each annual anniversary of the rent commencement date. We have the option to extend this lease for two additional five-year periods after the initial term. In March 2025, we announced a pause on our CAR-T research and development activities. As a result, we are winding down activities at the ARC lab and actively seeking to sublease the facility. We considered this to be a triggering event and performed an impairment analysis on the right-of-use asset. For the nine months ended September 30, 2025, we recorded a non-cash impairment of the right-of-use asset of $4.1 million, representing the amount by which the carrying value of the right-of-use asset exceeded its estimated fair value. We recorded the impairment loss within research and development expenses on the accompanying condensed consolidated statements of operations and comprehensive income (loss). The remaining ROU asset and lease liability for the ARC facility remain on our balance sheet.

In February 2017, we entered into a lease agreement (the ATOM Lease) for approximately 90,580 square feet of office, lab and cellular therapy manufacturing space in Thousand Oaks, California (the ATOM Facility). The initial 15-year term of the headlease commenced on February 15, 2018, upon the substantial completion of landlord’s work as defined under the agreement. In April 2022, we assigned the ATOM Lease to FDB in connection with the closing of the sale of the ATOM Facility to FDB. Under ASC 842, we are considered to be the sub-lessor of the ATOM Lease. We have not received novation from the landlord and therefore have not been relieved of our primary obligations under the headlease. Therefore, the ROU asset and lease liability for the ATOM Facility remain on our balance sheet. Given the continued use of the ATOM lease by another party, we did not consider there to be a trigger for valuation considerations following our restructuring activities.

We evaluated our vendor contracts to identify embedded leases and determined that the Master Services and Supply Agreement (Fujifilm MSA) we entered into with FUJIFILM Diosynth Biotechnologies California, Inc. (FDB) contained items that constituted a lease under ASC 842, Leases, as Atara has the right to substantially all of the economic benefits from the use of the asset and can direct the use of the asset. We concluded that the Fujifilm MSA contains an embedded operating lease for certain dedicated processing rooms for the manufacturing of Atara product and an embedded finance lease for certain freezers dedicated for our use. The Fujifilm MSA includes contractual obligations in the form of payments for the processing rooms and the freezers, each over a term of five years. As a result, we added ROU assets and lease liabilities for the processing rooms and freezers for the initial term of the lease in the amounts of $50.8 million and $4.8 million, respectively. In November 2023, we agreed to forego the use of one processing room for approximately one year in return for a reduction in contractual obligations under the Fujifilm MSA, and in November 2024, we exercised the option to release the processing room to FDB for the remainder of the initial term. The Fujifilm MSA was novated to Pierre Fabre in March 2025 as part of the A&R Commercialization Agreement Amendment. As of June 30, 2025, we were relieved of our primary obligations under the Fujifilm MSA. Therefore, the ROU assets and lease liabilities for the processing rooms and the freezers have been removed from our condensed consolidated balance sheet as of June 30, 2025. At the time of this release in June 2025, we recognized a gain on derecognition of the operating lease liability of $0.7 million and a gain on derecognition of the finance lease liability of $0.5 million within research and development expenses on the accompanying condensed consolidated statements of operations and comprehensive income (loss).

Additionally, in 2021, we entered into an amended lease agreement (Aurora Lease) for our office and lab space in Aurora, Colorado, to add additional lab space and in November 2023, we further amended the Aurora Lease to extend the term to April 2025. The lease agreement expired on April 30, 2025, and the ROU asset and lease liability for the Aurora Lease are no longer on our balance sheet.

We originally leased office space in South San Francisco, California under a non-cancellable lease agreement. In December 2021, we entered into a second amendment with the landlord to extend the lease term through May 2025. The amended lease agreement does not include an option to extend the lease term. In connection with the amended lease, we were required to maintain a letter of credit in the amount of $0.1 million to the landlord. In October 2022, we entered into a sub-lease agreement with a third party for this office space. The sub-lease term commenced in November 2022 and expired in May 2025. At the expiration of the lease in May 2025 our ROU asset and lease liability for the South San Francisco office were removed from our balance sheet and the requirement to maintain a letter of credit was released.

We have no finance leases as of September 30, 2025. The maturities of lease liabilities under our operating leases as of September 30, 2025 were as follows:


	Operating Leases
Years Ending December 31,	(in thousands)
2025		1,017
2026		3,258
2027		3,226
2028		3,319
2029		3,415
Thereafter		9,043
Total lease payments	$	23,278
Less: amount representing interest		(6,320	)
Present value of lease liabilities	$	16,958

Balance as of September 30, 2025
Other current liabilities	$	1,953
Operating lease liabilities - long-term		15,005
Other long-term liabilities		—
Total	$	16,958

The components of lease cost were as follows:


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
	(in thousands)				(in thousands)
Operating lease cost:
Operating lease cost	$	502	$	4,293	$	4,900	$	12,879
Short-term lease cost		—		48		42		145
Total operating lease cost	$	502	$	4,341	$	4,942	$	13,024
Finance lease cost:
Amortization expense	$	—	$	240	$	240	$	719
Interest on lease liabilities		—		79		66		254
Total finance lease cost	$	—	$	319	$	306	$	973

Atara Biotherapeutics, Inc. 10-Q