Leases classified as operating leases are included in operating lease right-of-use assets (“ROU”), operating lease liabilities, current portion and operating lease liabilities, net of current portion, in the Company's consolidated balance sheets.

The Company leases its office and facilities in Boston, Massachusetts under a non-cancellable operating lease agreement that continues through December 31, 2032. Under the terms of the lease agreement, the Company is responsible for certain insurance, property taxes and maintenance expenses, which represents the Company’s proportionate share of the actual expenses incurred by the landlord. The operating lease agreement contains scheduled annual rent increases over the lease term.

On February 2, 2023, the Company entered into a sublease agreement for approximately 17,729 square feet of office and laboratory space in the building located at 321 Harrison Avenue, Boston, Massachusetts. The sublease included a rent-free period, with rent payments commencing on May 24, 2023. Under the terms of the sublease, the sublessee is to pay the Company approximately $1.5 million in year one and $1.9 million per year thereafter, which is subject to a 3.0% annual rent increase, plus certain other costs under the sublease, such as operating expenses, taxes, insurance, property management fee and utilities. The Company remains jointly and severally liable under the head lease and accounts for the sublease as an operating lease. The sub-lease term commenced on March 24, 2023 and is expected to end in March 2026. The sublessee has the option to extend the sublease for a one-year period on the same terms and conditions as the current sublease, subject to a change in base rent for the extended period equal to a 3% increase to the then current rent. Upon execution of the sublease agreement, the sublessee provided the Company a security deposit of $0.4 million which is held in the form of a letter of credit. The Company recognized sublease income of $1.8 million for the year ended December 31, 2023.

The Company was not party to any finance leases during the years ended December 31, 2023 and 2022.

The components of lease expense were as follows (in thousands):


	Year Ended December 31,
	2023		2022
Lease cost
Operating lease cost	$	2,666	$	1,978
Variable lease cost		753		121
Short-term lease cost		499		1,681
Total lease cost	$	3,918	$	3,780


Other information
Operating lease right-of-use asset obtained in exchange for new operating lease liabilities	$	—		$	14,497
Cash paid for amounts included in the measurement of lease liabilities, included in operating cash flows	$	2,516		$	663
Weighted-average remaining lease term (in years)		9.00			10.00
Weighted-average discount rate		9.40	%		9.40	%

Variable lease costs primarily relate to common area costs and other operating costs, which are assessed based on the Company’s proportionate share of such costs for the leased premises. Total lease costs are included as operating expenses in the Company’s consolidated statements of operations and comprehensive loss.

Maturities of lease liabilities as of December 31, 2023, were as follows (in thousands):


Years Ending December 31,	Operating Lease Payments			Sublease Receipts		Net Operating Lease Payments
2024	$	3,185		$	1,844	$	1,341
2025		3,278			1,898		1,380
2026		3,375			437		2,938
2027		3,473			—		3,473
2028		3,575			—		3,575
Thereafter		15,383			—		15,383
Total undiscounted payments	$	32,269		$	4,179	$	28,090
Less: present value adjustment		(10,938	)
Present value of future payments		21,331
Less: current portion of operating lease liabilities		(1,232	)
Operating lease liabilities, net of current portion	$	20,099