The Company has historically entered into lease arrangements for its facilities and certain equipment. As of March 31, 2022, the Company had one operating lease with required future minimum payments related to its headquarters in Lexington, MA.

In November 2019, the Company entered into a lease agreement for office, laboratory and vivarium space located at 65 Hayden Avenue, Lexington, Massachusetts (“65 Hayden Ave Lease”) to replace the Company’s prior headquarters located at 99 Erie Street Cambridge, Massachusetts. Under the terms of the 65 Hayden Ave Lease, the Company leases approximately 23,901 square feet of space and pays an initial annual base rent of approximately $1,494, which is subject to scheduled annual increases, plus certain operating expenses and taxes. The Company took possession of the space on April 1, 2020 (“Lease Commencement Date”) and the lease will continue through July 1, 2025 (“Lease Termination Date”). The Company has an option to extend the lease for a single additional term of 5 years. Upon execution of the 65 Hayden Ave Lease, the Company executed a $622 cash-collateralized letter of credit. Lease payments are due in monthly installments through the Lease Termination Date.

At the Lease Commencement Date, the Company performed a lease assessment under the guidance prescribed in ASC Topic 842, Leases (“ASC 842”), and concluded that the 65 Hayden Ave Lease was an operating lease. As such, the Company recorded an

operating lease right-of-use asset and corresponding operating lease liability on the consolidated balance sheets of $6,428 which reflected the net present value of future payments under the lease. The discount rate used to calculate the net present value of future payments was the Company’s incremental borrowing rate at the Lease Commencement Date, which was 7.6%.

The following table contains a summary of the lease costs recognized under ASC 842 and other information pertaining to the Company’s operating leases for the three months ended March 31, 2022 and 2021:

	Three Months Ended March 31,
	2022		2021
Operating leases
Lease cost
Operating lease cost	$	378	$	378
Variable lease cost		223		215
Total lease cost	$	601	$	593
Other year-to-date lease information
Operating cash flows used for operating leases	$	385	$	373
Operating lease liabilities arising from obtaining right-of-use assets	$	—	$	—

The following table contains a summary of the lease liabilities recognized on the Company’s unaudited condensed consolidated balance sheet as of March 31, 2022 and on the Company’s audited consolidated balance sheet as of December 31, 2021:

	As of March 31, 2022			As of December 31, 2021
Other operating lease information
Operating lease liabilities — short-term	$	1,262		$	1,227
Operating lease liabilities — long-term	$	3,397		$	3,725
Weighted-average remaining lease term	3.3 years			3.5 years
Weighted-average discount rate		7.60	%		7.60	%

The variable lease costs for the three months ended March 31, 2022 and 2021 include common area maintenance and other operating charges. As the Company’s leases do not provide an implicit rate, the Company utilized its incremental borrowing rate based on what it would normally pay to borrow on a collateralized basis over a similar term for an amount equal to the lease payments at the commencement date in determining the present value of lease payments.

Future minimum lease payments under the Company’s operating lease as of March 31, 2022 and December 31, 2021, were as follows:

	As of March 31, 2022			As of December 31, 2021
Maturity of lease liabilities
2022	$	1,177		$	1,562
2023		1,609			1,609
2024		1,656			1,656
2025		841			841
Thereafter		—			—
Total lease payments		5,283			5,668
Less: imputed interest		(624	)		(716	)
Total operating lease liabilities	$	4,659		$	4,952