Leases

12 Months Ended

Dec. 31, 2023

Leases

Leases

7. Leases

The Company has an operating lease for its headquarters and a finance lease for certain lab equipment. In August 2019, the Company entered into a facility lease agreement with a landlord providing funding for tenant improvements and occupancy of approximately 27,830 square feet of office and laboratory space (the “premises”) at 828 Winter Street, Waltham, Massachusetts. The initial term of the lease expires in March 2030, unless terminated earlier in accordance with the terms of the lease. The Company has a right to a five-year option to extend at then-market rates. The Company is obligated to pay its portion of real estate taxes and costs related to the premises, including costs of operations, maintenance, repair, replacement, and management of the leased premises, which it began paying simultaneous with the rent commencement date in March 2020. As of December 31, 2023 and 2022, the Company has a letter of credit for the benefit of its landlord in the amount of $1.6 million, collateralized by a money market account, which is recorded as restricted cash on the consolidated balance sheets.

The components of lease expense were as follows:

	Year Ended
	December 31,
	2023		2022
Operating lease cost	$	1,225	$	1,225
Variable lease cost		982		959
Total lease costs	$	2,207	$	2,184
Finance lease cost:
Amortization of right-of-use asset	$	85	$	85
Interest on lease liability		6		12

Supplemental balance sheet information related to the leases was as follows (in thousands, except for remaining lease term and discount rates):

	Year Ended
	December 31,
	2023			2022
Operating Lease:
Operating lease right-of-use asset	$	5,125		$	5,585
Operating lease liability, current portion	$	1,047		$	918
Operating lease liability, net of current portion	$	8,142		$	9,189
Finance Lease:
Other non-current assets	$	134		$	219
Other current liabilities		48			82
Other liabilities, long-term		—			45
Weighted-average remaining lease term (in years):
Operating lease		6.2			7.2
Finance lease		0.7			1.7
Weighted-average discount rate:
Operating lease		8.0	%		8.0	%
Finance lease		6.9	%		6.9	%

Supplemental cash flow information related to leases was as follows:

		Year Ended
		December 31,
		2023		2022
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	1,683	$	1,634
Financing cash flows from finance leases		85		85

Future minimum lease payments under non-cancellable leases as of December 31, 2023 are as follows:

	Operating Lease		Finance Lease
2024	$	1,733	$	49
2025		1,785		—
2026		1,839		—
2027		1,894		—
2028		1,951		—
Thereafter		2,516		—
Total future minimum lease payments		11,718		49
Present value adjustment		(2,529)		(1)
Present value of lease liabilities	$	9,189	$	48