In December 2021, the Company entered into a non-cancellable operating lease agreement, or the Harrison Lease, pursuant to which the Company leases 31,668 square feet of office and laboratory space located in Boston, Massachusetts, or the Premises. The Harrison Lease commenced for accounting purposes when the Company gained access to the Premises on December 29, 2022, or the Lease Commencement Date. The Harrison Lease has a term of nine years and two months from the Lease Commencement Date. The Company’s obligation for the payment of base rent for the Premises began in May 2023, and is $0.2 million per month, increasing up to $0.3 million per month during the term of the Lease. The Company has one option to extend the term of the Harrison Lease, for a period of an additional five years. Due to the timing of the Lease Commencement Date at the end of 2022, there was no fixed lease rent expense associated with the Harrison Lease in 2022. At December 31, 2023, the Harrison Lease was the only lease for which the Company recorded a lease liability and corresponding right-of-use asset.

The landlord completed significant leasehold improvements to the Premises, a portion of which the Company was obligated to pay per the terms of the Harrison Lease. The Company paid $2.0 million for the improvements prior to lease commencement in 2022, and paid $3.4 million for the improvements in 2023, for total payments to the landlord for improvements of $5.4 million. The Company determined that the landlord is the accounting owner of the improvements, and payments by the Company for the improvements are included in the calculation of the right-of-use asset and lease liability.

During 2022 and the first quarter of 2023, the Company leased office space in Cambridge, Massachusetts, the terms of which were month-to-month, with a 30-day written notice of cancellation. The Company terminated this lease in January 2023. The Company also leased laboratory space at the University of Massachusetts, Mount Ida Campus in Newton, Massachusetts, with an

initial lease term from February 1, 2022 to January 31, 2023, which the Company extended until March 2023. The Company also leased space at Innovation Building, University of Oxford in Oxford, U.K. The Company terminated its lease in Oxford in July 2022. All of these leases had initial terms of under 12 months and are considered short-term lease costs and are not recognized on the consolidated balance sheets.

The components of lease cost under ASC 842 for the leases were as follows (in thousands):


	2023		2022
Fixed lease cost	$	3,799	$	—
Variable lease cost		993		—
Short-term lease cost		188		1,294
Total lease cost	$	4,980	$	1,294

Cash payments for operating leases during 2023 related to tenant improvements of $3.4 million and $1.9 million in rent payments in line with the Harrison Lease. Additionally, the Company made payments on variable lease costs throughout the year of $1.0 million. These payments related to parking, management fees, and other costs associated with maintaining our office and lab space.

The remaining lease term for the Harrison Lease is 8.4 years, and the discount rate is 8.0%.

Future minimum lease payments under the non-cancelable operating lease consisted of the following as of December 31, 2023:


Year Ending December 31,	(in thousands)
2024	$	3,004
2025		3,094
2026		3,187
2027		3,282
2028		3,381
Thereafter		12,079
Total future minimum lease payments	$	28,027
Less: imputed interest		(7,923	)
Present value of lease liability	$	20,104

Included in the consolidated balance sheet (in thousands)	December 31, 2023
Lease liability	$	3,004
Lease liability, net of current portion		17,100
Total lease liability	$	20,104