In December 2017, the Company entered into a facility lease agreement for approximately 44,336 square feet of office and laboratory space at 399 Binney Street, Cambridge, Massachusetts, which was increased to 44,807 square feet in January 2018. The Company gained control of the leased space in January 2019 and recorded a right of use asset and a lease liability, accordingly. The lease expires in April 2029, subject to certain renewal options, which have not been included in the Company’s right of use asset and liability, as the Company is not reasonably certain to exercise those options.

In September 2020, the Company entered into an amendment to its facility lease agreement to expand the leased area by approximately 1,824 square feet of office space at 399 Binney Street, Cambridge, Massachusetts. The amended lease expires in April 2029, subject to certain renewal options. The amendment to the lease agreement met the criteria to be accounted for as a separate lease. The Company gained control of the leased space in October 2020 and recorded a right of use asset and a lease liability, accordingly. The right of use asset and lease liability recorded in connection with this amendment were not material.

As discussed in Note 2, the Company provided a letter of credit in the amount of $0.9 million with a financial institution, which expires September 30, 2028.

The following table summarizes the presentation of amounts recorded on the Company’s consolidated balance sheets for the operating lease at 399 Binney Street:


		December 31,
	Balance sheet location	2021		2020
Assets:
Operating lease assets	Operating lease assets	$	20,780	$	22,579
Liabilities:
Current operating lease liabilities	Operating lease liabilities	$	1,844	$	1,521
Non-current operating lease liabilities	Operating lease liabilities, net of current portion		21,056		22,901
	Total lease liabilities	$	22,900	$	24,422

The following table summarizes the effect of lease costs for the Company’s operating lease at 399 Binney Street on Company’s consolidated statements of operations and comprehensive loss for the years ended December 31, 2021, 2020 and 2019:


		Year Ended December 31,
	Statement of operations location	2021		2020		2019
Operating lease costs	Research and development	$	3,262	$	3,273	$	3,216
	General and administrative	846		748			581
	Total operating lease cost	$	4,108	$	4,021	$	3,797

The Company made cash payments of $5.4 million, $4.9 million and $2.6 million under the lease agreement for 399 Binney Street during the years ended December 31, 2021, 2020 and 2019, respectively.

The minimum lease payments for the Company’s operating lease at 399 Binney Street as of December 31, 2021 for the next five years and thereafter is expected to be as follows:


Year Ending December 31,	Amount
2022		4,134
2023		4,254
2024		4,377
2025		4,503
2026		4,634
Thereafter		11,325
Total lease payments		33,227
Less: interest		(10,327	)
Present value of operating lease liabilities	$	22,900

The weighted average remaining lease term and weighted average discount rate of the operating lease were 7.3 years and 10.4%, respectively, at December 31, 2021 for the Company’s operating lease at 399 Binney Street. The weighted average remaining lease term and weighted average discount rate of the operating lease were 8.3 years and 10.4%, respectively, at December 31, 2020 for the Company’s operating lease at 399 Binney Street.

On May 26, 2021, the Company entered into a lease agreement for laboratory and office space located at 60 Hampshire Street, Cambridge, Massachusetts (the “Hampshire Lease”). Under the terms of the Hampshire Lease, the Company will lease approximately 41,474 square feet as the sole tenant, which will supplement the Company’s current leased premises at 399 Binney Street, Cambridge, Massachusetts. The landlord will contribute an aggregate of $6.2 million toward the cost of construction and tenant improvements for the premises. In total, fixed lease payments, which include base rent, landlord fees, and parking, are $55.7 million over the lease term. The Company’s obligation to pay rent under the Hampshire Lease will start on a date set forth in an estimated construction schedule pursuant to the Hampshire Lease or the date on which the landlord tenders possession of the premises to the Company with the tenant improvements substantially completed, whichever occurs later. The term of the Hampshire Lease is ten years following the rent commencement, which is currently expected in 2022. The Company did not control the space or any of the assets being constructed therein as of December 31, 2021 and further concluded the improvements being constructed therein are the landlord’s assets with alternative use to future tenants. As such, no right of use asset or lease liability was recorded on the consolidated balance sheet at December 31, 2021, since lease commencement, for accounting purposes, had not been triggered.

As discussed in Note 2, the Company provided a letter of credit in connection with the Hampshire Lease in the amount of $1.7 million with a financial institution, which expires August 31, 2033.