Leases	6 Months Ended
Jun. 30, 2022
Leases [Abstract]
Leases	12. LEASES Lease Arrangements The Company enters into lease arrangements for its facilities. A summary of the arrangements is as follows: Operating Leases Lexington On September 26, 2016, and as amended on December 31, 2016, the Company entered into a 10 year and 9-month lease , which includes two successive five-year renewal options, for its facility in Lexington, Massachusetts (the “Lexington Lease”), which the Company uses primarily for its current good manufacturing practices (“cGMP”) manufacturing, as well as for additional laboratory and office space. Throughout the term of the Lexington Lease, the Company is responsible for paying certain costs and expenses, in addition to the rent, as specified in the lease, including a proportionate share of applicable taxes, operating expenses and utilities. As required under the terms of the Lexington Lease, the Company had restricted cash of approximately $2.7 million in a separate bank account as of June 30, 2022 and December 31, 2021. Cambridge In April 2015, the Company entered into a lease agreement for an office and laboratory facility in Cambridge, Massachusetts (the “Cambridge Lease”), which commenced in October 2015 with a term of 7.5 years with a five-year renewal option to extend the lease. Throughout the term of the Cambridge Lease, the Company is responsible for paying certain costs and expenses, in addition to the rent, as specified in the lease, including a proportionate share of applicable taxes, operating expenses and utilities. As required under the terms of the Cambridge Lease, the Company had restricted cash of $1.0 million in a separate bank account as of June 30, 2022 and December 31, 2021. In December 2020, the Company exercised its option under the Cambridge Lease to lease additional office and laboratory space at the adjoining facility. The combined space constitutes the entire building located at 733 Concord Avenue. The lease for the additional space commenced on October 1, 2021, with a term of five years and, for accounting purposes, is considered a separate lease from the Cambridge Lease (the “Additional Cambridge Lease”). On the commencement date of the Additional Cambridge Lease, the Company recorded a right-of-use asset and corresponding operating lease liability of $4.5 million and began recognizing straight-line rent expense under ASC 842. Throughout the term of the Additional Cambridge Lease, the Company is responsible for paying certain costs and expenses, in addition to the rent, as specified in the lease, including a proportionate share of applicable taxes, operating expenses and utilities. In June 2022, the Company notified the landlord of its intention to exercise the five-year renewal option under the Cambridge Lease to extend the lease term through March 2028 (the “Cambridge Lease Extension”). In June 2022, the Company calculated an incremental borrowing rate of 10.53% and remeasured the right-of-use asset and the lease liabilities related to the Cambridge Lease Extension. As of June 30, 2022, the Company recorded an additional $12.0 million of operating right-of-use asset and corresponding operating lease liabilities relating to the Cambridge Lease Extension. In August 2022, the Company executed the second amendment to the Cambridge Lease with respect to the Cambridge Lease Extension.

Leases

6 Months Ended

Jun. 30, 2022

12. LEASES

Lease Arrangements

The Company enters into lease arrangements for its facilities. A summary of the arrangements is as follows:

Operating Leases

Lexington

On September 26, 2016, and as amended on December 31, 2016, the Company entered into a 10 year and 9-month lease , which includes two successive five-year renewal options, for its facility in Lexington, Massachusetts (the “Lexington Lease”), which the Company uses primarily for its current good manufacturing practices (“cGMP”) manufacturing, as well as for additional laboratory and office space. Throughout the term of the Lexington Lease, the Company is responsible for paying certain costs and expenses, in addition to the rent, as specified in the lease, including a proportionate share of applicable taxes, operating expenses and utilities. As required under the terms of the Lexington Lease, the Company had restricted cash of approximately $2.7 million in a separate bank account as of June 30, 2022 and December 31, 2021.

Cambridge

In April 2015, the Company entered into a lease agreement for an office and laboratory facility in Cambridge, Massachusetts (the “Cambridge Lease”), which commenced in October 2015 with a term of 7.5 years with a five-year renewal option to extend the lease. Throughout the term of the Cambridge Lease, the Company is responsible for paying certain costs and expenses, in addition to the rent, as specified in the lease, including a proportionate share of applicable taxes, operating expenses and utilities. As required under the terms of the Cambridge Lease, the Company had restricted cash of $1.0 million in a separate bank account as of June 30, 2022 and December 31, 2021.

In December 2020, the Company exercised its option under the Cambridge Lease to lease additional office and laboratory space at the adjoining facility. The combined space constitutes the entire building located at 733 Concord Avenue. The lease for the additional space commenced on October 1, 2021, with a term of five years and, for accounting purposes, is considered a separate lease from the Cambridge Lease (the “Additional Cambridge Lease”). On the commencement date of the Additional Cambridge Lease, the Company recorded a right-of-use asset and corresponding operating lease liability of $4.5 million and began recognizing straight-line rent expense under ASC 842. Throughout the term of the Additional Cambridge Lease, the Company is responsible for paying certain costs and expenses, in addition to the rent, as specified in the lease, including a proportionate share of applicable taxes, operating expenses and utilities.

In June 2022, the Company notified the landlord of its intention to exercise the five-year renewal option under the Cambridge Lease to extend the lease term through March 2028 (the “Cambridge Lease Extension”). In June 2022, the Company calculated an incremental borrowing rate of 10.53% and remeasured the right-of-use asset and the lease liabilities related to the Cambridge Lease Extension. As of June 30, 2022, the Company recorded an additional $12.0 million of operating right-of-use asset and corresponding operating lease liabilities relating to the Cambridge Lease Extension. In August 2022, the Company executed the second amendment to the Cambridge Lease with respect to the Cambridge Lease Extension.