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 moved our headquarters to Atara Research Center (ARC), our existing office, lab, and warehouse space in Thousand Oaks, California. In March 2021, we entered into a lease agreement for the 33,659 square feet of office, lab and warehouse space at 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.

Additionally, in 2021, we entered into an amended lease agreement for our office and lab space in Aurora, Colorado, to add additional lab space and in November 2023, we further amended the lease agreement for our office and lab space in Aurora, Colorado, to extend the term of the lease agreement to April 2025.

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 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.

We evaluated our vendor contracts to identify embedded leases and determined that the Fujifilm MSA 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.

We lease 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 are 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 expires in May 2025, with no option to extend the sub-lease term. 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 South San Francisco office remain on our balance sheet.

The maturities of lease liabilities under our operating and finance leases as of December 31, 2024 were as follows:


	Operating Leases				Finance Leases
Years Ending December 31,		(in thousands)
2025		$	17,004			$	1,263
2026			15,677				1,285
2027			5,494				437
2028			3,319				—
2029			3,415				—
Thereafter			9,044				—
Total lease payments		$	53,953			$	2,985
Less: amount representing interest			(11,160	)			(346	)
Present value of lease liabilities		$	42,793			$	2,639

Balance as of December 31, 2024
Other current liabilities		$	12,879			$	1,038
Operating lease liabilities – long-term			29,914				—
Other long-term liabilities			—				1,601
Total		$	42,793			$	2,639

The components of lease cost were as follows:


	Year Ended		Year Ended
	December 31, 2024		December 31, 2023
	(in thousands)
Operating lease cost:
Operating lease cost	$	16,930	$	17,192
Short-term lease cost		193		201
Total operating lease cost	$	17,123	$	17,393
Finance lease cost:
Amortization expense	$	959	$	976
Interest on lease liabilities		326		416
Total finance lease cost	$	1,285	$	1,392

Other information related to leases was as follows:


	Year Ended			Year Ended
	December 31, 2024			December 31, 2023
	(in thousands, except lease term and discount rate)
Supplemental Cash Flows Information
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows for operating leases	$	16,019		$	16,660
Operating cash flows for finance leases		326			416
Financing cash flows for finance leases		892			947

Operating lease assets obtained in exchange for lease obligations:	$	—		$	312
Finance lease assets obtained in exchange for lease obligations:		—			—
Non-cash (decrease) increase to operating lease assets due to remeasurement of lease liabilities:		(3,002	)		(1,589	)

Weighted Average Remaining Lease Term
Operating leases	4.7 years			5.2 years
Finance leases	2.3 years			3.3 years
Weighted Average Discount Rate
Operating leases		11.2	%		11.4	%
Finance leases		10.4	%		10.4	%

Our asset retirement obligation (ARO) consists of a contractual requirement to remove the tenant improvements at the ATOM Facility in Thousand Oaks, California and restore the facility to a condition specified in the lease agreement. Although we assigned the ATOM Lease to FDB in connection with the closing of the sale of the ATOM Facility to FDB in April 2022, we have not received novation from the landlord. Therefore, the ARO associated with the ATOM Facility remains on our balance sheet. We recorded an estimate of the fair value of our ARO liability in other long-term liabilities and the ARO asset as a long-term asset in the period incurred. The fair value of the ARO asset is amortized over the lease term. The fair value of our ARO was estimated by discounting projected cash flows over the estimated life of the related assets using our credit adjusted risk-free rate. As of December 31, 2024 and December 31, 2023, the ARO asset and liability were not material.