Since September 2017, the Company has had an arrangement with Cell Therapy Catapult Limited to lease manufacturing suites at the Cell and Gene Therapy Catapult manufacturing center in Stevenage, United Kingdom. In March 2023, the Company and Cell Therapy Catapult Limited mutually agreed: (i) to terminate the lease relating to the leased manufacturing suite which originally had a lease term until February 2025, (ii) to extend the lease term of one of the remaining manufacturing suites from June 2023 to August 2024, and (iii) to extend the lease term of a third manufacturing suite leased by the Company from September 2023 to August 2024. In August 2024, one of the leased manufacturing suites ended and the Company exited the suite. In September 2024, the Company extended the lease term from August 2024 to December 2026 for the remaining manufacturing suite.

In January 2019, the Company executed a lease agreement with Whitewood Media Village GP Limited and Whitewood Media Village Nominee Limited to lease the fifth floor of MediaWorks including laboratory space. The Company has the option to terminate the lease in November 2026. In August 2021, MediaWorks became the Company's main corporate headquarters. In addition to base rent, the Company is obligated to pay its proportionate share of building operating expenses and real estate taxes in excess of base year amounts. These costs are considered to be variable lease payments and are not included in the determination of the lease’s right-of-use asset or lease liability. The lease agreement includes an option to lease additional space. The lease term is nine years and eleven months with an eighteen-month rent free period at the beginning of the lease term. In addition, in January 2026, the Company entered into an amendment to the lease agreement that extended the lease term into November 2035. The amendment provides certain rent-free and reduced rent periods as an incentive, and includes a break window during which the Company may terminate the lease early in exchange for payment of a pre-specified rent penalty.

In February 2019, the Company agreed to enter into a fifteen-year lease for manufacturing space units located in Enfield, United Kingdom, provided that the landlord completed the required leasehold improvements described in the agreement. The Company executed these lease agreements for 3 manufacturing space units, each for fifteen-year lease terms upon such completion. The leases commenced in February 2019, with the option to terminate the lease in February 2029. In addition to base rent, the Company is obligated to pay its proportionate share of building operating expenses and real estate taxes in excess of base year amounts. These costs are considered to be variable lease payments and are not included in the determination of the lease’s right-of-use asset or lease liability. In March 2021, one of the units was split in two separate units and the Company surrendered one of those units back to the landlord. The Company has no further obligations for the surrendered unit and the right of use asset and lease liability which were recorded for this unit were written off during the year ended December 31, 2021. In October 2021, the Company subleased two of the three remaining units to third parties with lease terms ending in February 2029 and October 2026, respectively. The Company completed an asset impairment analysis of the right-of-use lease concluding the undiscounted cash flows exceeded the carrying value as of December 31, 2025 which resulted the recognition of a $0.3 million impairment of operating lease right-of-use assets and related property and equipment.

On September 19, 2023, the Company entered into a 20-year lease agreement with the landlord for The Nucleus. The Company made fit-out costs in other areas of the building which may be required to be removed at the end of the lease term. On September 10, 2024, the Company completed a variation of the lease for the manufacturing facility, related to additional works at the site. The landlord will provide funding for certain specified improvements to the facility (the “Works”), which the Company commits to undertake on a mutually agreed schedule. Funding received for the Works done are deemed lease incentives in accordance with ASC 842. Once the Works are complete, the rental payments under the lease will be increased according to a specified formula for the remainder of the lease term from December 2025. The deed of variation does not affect the lease term, which continues to run for 20 years from September 19, 2023. In the three months ended December 31, 2025, the landlord handed over various portions of the facility upon the completion of the Works. The Company made fit-out costs in other areas of the building and may be required to be removed at the end of the lease term. As a result, as of December 31, 2025, the Company has recognized an estimated Asset Retirement Obligation (“ARO”) amounting to $0.4 million. The Company will continue to assess the ARO as more related assets are brought into use.


		Year ended December 31,
Lease costs	Statement of Operations Classification	2025		2024
Operating lease costs	Research and development expenses, net	$	2,199	$	6,642
Variable costs	Research and development expenses, net	958		1,281
Short term lease costs	Research and development expenses, net	1,269		258

Operating lease costs	Selling, general and administrative expenses	4,518		1,393
Variable costs	Selling, general and administrative expenses	753		318
Short term lease costs	Selling, general and administrative expenses	100		117

Operating lease costs	Cost of sales	2,021		558
Variable costs	Cost of sales	228		64
Short term lease costs(1)	Cost of sales	(942)		—
Total Lease Costs		$	11,104	$	10,631
(1) Includes lease incentives received during the year ended December 31, 2025 relating to the Company's Nucleus facility lease.


	Year ended December 31,
Other information	2025			2024
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash outflows from operating leases (in thousands)(1)	$	(5,554)		$	4,258


Weighted-average remaining lease term - operating leases (in years)	16.1 years			15.9 years
Weighted-average discount rate - operating leases	8.08		%	8.15		%
(1) Includes lease incentives received during the year ended December 31, 2025 relating to the Company's Nucleus facility lease.