Right of Use Assets and Liabilities

12 Months Ended

Dec. 31, 2025

Right-of-Use Assets and Liabilities

In August 2024, the Company entered into a Lease Termination Agreement with 101 College Street LLC (the "Landlord"). Under the terms of the Lease Termination Agreement, the lease, by and between the Company and the Landlord, dated May 4, 2021 (as amended, the "Terminated Lease"), for certain leased premises of approximately 160,000 square feet of laboratory and office space, was terminated in full, effective August 15, 2024. The leased premises were expected to be occupied by the Company in 2025. In connection with the Lease Termination Agreement and as consideration for the Landlord’s agreement to terminate the lease for its laboratory and office space at 101 College Street in full, the Company agreed to pay to the Landlord a one-time cash termination fee in the amount of $41.5 million and wrote-off $1.9 million of prepaid rent, both of which were recognized in general and administrative operating expenses on the consolidated statements of operations. The Company also cancelled its previously issued letter of credit in the amount of $5.5 million.

The Company has operating leases for its corporate office, laboratories and certain equipment, which expire no later than December 2029. The leases have a weighted-average remaining term of 4.0 years.

The components of lease expense were as follows:


	Year Ended December 31,
(dollars in millions)	2025		2024		2023
Operating lease cost	$	2.9	$	1.9	$	2.1

Supplemental cash flow information related to leases was as follows:


	December 31,
(dollars in millions)	2025		2024		2023
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	2.0	$	1.9	$	2.0
Supplemental non-cash information:
Right-of-use assets obtained in exchange for new lease obligations	$	1.5	$	8.5	$	—

In December 2024, the Company, entered into a Seventh Amendment and an Eighth Amendment to its lease (collectively the “Seventh and Eighth Building 5 Lease Amendments") with Science Park Development Corporation for certain premises in New Haven, Connecticut (the “Building 5 Premises”). The Seventh and Eighth Building 5 Lease Amendments extend the term of the original lease to December 31, 2029, resulting in an increase in the Company's ROU assets of $8.5 million, and, effective on January 1 2025, expand the Building 5 Premises to include approximately 11,200 square feet of additional laboratory and office space resulting in an increase in the Company's ROU assets of $1.5 million. The annual base rent during the extended term will range from $2.2 million to $2.6 million.

Maturities of operating lease liabilities as of December 31, 2025 were as follows:


(dollars in millions)
2026	$	2.3
2027	2.4
2028	2.5
2029	2.6


Total lease payments	9.8
Less: imputed interest	(1.3)
Total	$	8.5