Leases
 12 Months Ended
Dec. 31, 2022
Leases [Abstract]  
Leases Leases
Operating Leases
During the year ended December 31, 2022, the Company leased office and laboratory facilities in Cambridge, Massachusetts under one noncancelable operating lease, which is subject to two expiration dates based on two distinct leased spaces, expiring in January 2027 and August 2028.
In January 2018, the Company entered into a lease for office and laboratory space in Cambridge, Massachusetts (the “Initial Space”). The lease term commenced on January 28, 2019 and was scheduled to expire eight years from the commencement date. The initial annual base rent is approximately $3.8 million, and such amounts increased during the initial term by 3% annually on the anniversary of the commencement date.
In November 2018, the Company entered into a lease amendment for office and laboratory space in the same building (the “Expansion Space”). The lease term for the Expansion Space commenced on August 8, 2019 and was scheduled to expire approximately nine years from the commencement date. The initial annual base rent for the Expansion Space was approximately $2.5 million and such amount increased by 3% annually on the anniversary of the commencement date. The Company was obligated to pay its portion of real estate taxes and costs related to the Expansion Space, including costs of operations, maintenance, repair, replacement and property management.
In December 2022, the Company entered into an Agreement for Termination of Lease (the “Lease Termination Agreement”) relating to its two distinct leased spaces for office and laboratory space in Cambridge, Massachusetts (the “Cambridge Facility”). Under the Lease Termination Agreement, the Company’s lease for the Cambridge Facility terminated on January 31, 2023. Under the terms of the Lease Termination Agreement, the Company paid the landlord a lease termination payment, inclusive of the full amount of a letter of credit that the landlord held under the lease and rent previously paid by the Company to the landlord for the month of December 2022, of approximately $5.9 million in the fourth quarter of the year ended December 31, 2022, and the Company paid the landlord a subsequent payment of $1.1 million in the first quarter of the year ending December 31, 2023.
The Lease Termination Agreement terminated the lease on January 31, 2023. As the lease termination was effective at a future date, the Company accounted for the change as a lease modification that shortened the lease term. Upon the modification, the Company decreased its operating lease, right-of-use asset by an amount equal to the adjustment of its operating lease liabilities.

The Company evaluated its vendor contracts to identify embedded leases, if any, and noted that an agreement with a contract manufacturing supplier constituted a lease under ASC 842 as the Company has the right to substantially all the economic benefits from the use of the asset and can direct the use of the asset. The Company entered into the agreement during the first quarter of 2019. The lease commenced during March 2019 and was scheduled to expire 22 months from commencement date with no stated option to extend the term. The lease was cancelled prior to expiration during the first quarter of 2020, resulting in derecognition of the lease assets and operating lease liabilities.

As the Company’s leases do not provide an implicit rate, the Company utilized its incremental borrowing rate based on information available at the lease commencement date, which represents an internally developed rate that would be incurred to borrow, on a collateralized basis, over a similar term, an amount equal to the lease payments in a similar economic environment. The Company has elected to account for each lease component and its associated non-lease components as a single lease component and, therefore, has allocated all the contract consideration across lease components only. This may result in the initial and subsequent measurement of the balances of the right-of-use asset and lease liability for leases being greater than if the policy election was not applied. Assets under operating lease at December 31, 2022 were $2.7 million. The leases do not include any restrictions or covenants that had to be accounted for under the lease guidance.

As of December 31, 2022, minimum lease payments under the Company’s operating leases are as follows (in thousands):
Year ending December 31,
2023$1,100
2024—
2025—
2026—
2027—
Thereafter—
1,100
Less: imputed interest— 
$1,100
The Company has not entered any material financing leases as of December 31, 2022.
Lease Portfolio
The components of lease cost and supplemental balance sheet information for the Company’s lease portfolio were as follows (in thousands, except term and discount rate amounts):
Year ended December 31,
202220212020
Lease cost:
Operating lease cost$12,655 $8,173 $9,240 
Short-term lease cost— 41 24 
Variable lease cost3,058 3,723 1,916 
Sublease income— (719)(1,017)
Total lease cost$15,713 $11,218 $10,163 
Operating leases:
Operating lease, right-of-use-asset$2,679 $35,095 $40,447 
Operating lease liabilities$1,100 $9,015 $8,945 
Operating lease liabilities, net of current portion$— $28,291 $32,762 
Other information:
Weighted average remaining lease term - operating leases0.08 years5.80 years6.70 years
Weighted-average discount rate - operating leases— %7.60 %7.60 %