LEASES	9 Months Ended
Sep. 30, 2024
Leases [Abstract]
LEASES	13. LEASES The Company has real estate operating leases in Cambridge, Andover, Burlington and Bedford, Massachusetts, Dublin and Columbus, Ohio, and Durham, North Carolina that provide for scheduled annual rent increases over the lease term. The Company has also identified leases embedded in certain of its manufacturing and supply agreements as the Company determined that it controls the use of the facilities and related equipment therein. For more information related to the lease embedded in manufacturing and supply agreements with Catalent, Inc. (“Catalent”), please refer to Note 21, Commitments and Contingencies of the Company's Annual Report on Form 10-K for the year ended December 31, 2023. Bedford, Massachusetts On April 22, 2022, the Company entered into a lease agreement (the “Bedford Lease”) for 288,000 square feet of to-be-constructed research and development and manufacturing space in Bedford, Massachusetts. The term of the Bedford Lease commences upon the landlord’s completion of the initial construction of the core and shell of the building, at which time the Company will obtain control of the premises and commence internal construction activities. The Company has two options to extend the lease for a period of ten years each, exercisable under certain conditions and at a market rate determined in accordance with the lease agreement. In May 2022, in connection with the execution of the Bedford Lease, the Company issued a letter of credit collateralized by cash deposits of approximately $8.4 million, which was included in the other non-current assets of the Company’s unaudited condensed consolidated balance sheets. Such letter of credit shall be reduced to approximately $5.6 million at the commencement of the fourth rent year, provided certain conditions set forth in the Bedford Lease are satisfied. Undiscounted minimum rent payments due over the term of the lease aggregate to $307.4 million. Additionally, the Company is responsible for reimbursing the landlord for the Company’s share of the property’s operating expenses and property taxes. The Bedford Lease also provides for a tenant improvement allowance from the landlord of up to $72.0 million to be used towards costs incurred by the Company in the design and construction of the premises. The Company recorded the $72.0 million tenant improvement allowance as a reduction to right-of-use (“ROU”) assets and lease liabilities in May 2023 as the Company obtained control of the premises. In August 2024, the Company entered into an amendment to the Bedford Lease to extend the term in which the tenant improvement allowance could be reimbursed from the landlord (the “Bedford Amendment”). The Bedford Amendment extended the reimbursement period associated with the tenant improvement allowance through December 2, 2025. The Company also agreed to reimburse the landlord for certain costs incurred in order to fund the extension of the reimbursement period associated with the tenant improvement allowance, totaling $2.9 million. The Bedford Amendment was accounted for as a modification to the Bedford Lease. As of September 30, 2024, the Company had a lease liability and ROU asset of $131.7 million and $92.0 million, respectively, on its unaudited condensed consolidated balance sheets related to the Bedford Lease. Tenant improvement costs incurred by the Company that had been reimbursed by the landlord totaled $29.5 million through September 30, 2024 and were recorded as an increase to lease liabilities when received within the Company's unaudited condensed consolidated balance sheets.

LEASES

9 Months Ended

Sep. 30, 2024

13. LEASES

The Company has real estate operating leases in Cambridge, Andover, Burlington and Bedford, Massachusetts, Dublin and Columbus, Ohio, and Durham, North Carolina that provide for scheduled annual rent increases over the lease term. The Company has also identified leases embedded in certain of its manufacturing and supply agreements as the Company determined that it controls the use of the facilities and related equipment therein. For more information related to the lease embedded in manufacturing and supply agreements with Catalent, Inc. (“Catalent”), please refer to Note 21, Commitments and Contingencies of the Company's Annual Report on Form 10-K for the year ended December 31, 2023.

Bedford, Massachusetts

On April 22, 2022, the Company entered into a lease agreement (the “Bedford Lease”) for 288,000 square feet of to-be-constructed research and development and manufacturing space in Bedford, Massachusetts. The term of the Bedford Lease commences upon the landlord’s completion of the initial construction of the core and shell of the building, at which time the Company will obtain control of the premises and commence internal construction activities. The Company has two options to extend the lease for a period of ten years each, exercisable under certain conditions and at a market rate determined in accordance with the lease agreement.

In May 2022, in connection with the execution of the Bedford Lease, the Company issued a letter of credit collateralized by cash deposits of approximately $8.4 million, which was included in the other non-current assets of the Company’s unaudited condensed consolidated balance sheets. Such letter of credit shall be reduced to approximately $5.6 million at the commencement of the fourth rent year, provided certain conditions set forth in the Bedford Lease are satisfied.

Undiscounted minimum rent payments due over the term of the lease aggregate to $307.4 million. Additionally, the Company is responsible for reimbursing the landlord for the Company’s share of the property’s operating expenses and property taxes. The Bedford Lease also provides for a tenant improvement allowance from the landlord of up to $72.0 million to be used towards costs incurred by the Company in the design and construction of the premises. The Company recorded the $72.0 million tenant improvement allowance as a reduction to right-of-use (“ROU”) assets and lease liabilities in May 2023 as the Company obtained control of the premises.

In August 2024, the Company entered into an amendment to the Bedford Lease to extend the term in which the tenant improvement allowance could be reimbursed from the landlord (the “Bedford Amendment”). The Bedford Amendment extended the reimbursement period associated with the tenant improvement allowance through December 2, 2025. The Company also agreed to reimburse the landlord for certain costs incurred in order to fund the extension of the reimbursement period associated with the tenant improvement allowance, totaling $2.9 million. The Bedford Amendment was accounted for as a modification to the Bedford Lease.

As of September 30, 2024, the Company had a lease liability and ROU asset of $131.7 million and $92.0 million, respectively, on its unaudited condensed consolidated balance sheets related to the Bedford Lease. Tenant improvement costs incurred by the Company that had been reimbursed by the landlord totaled $29.5 million through September 30, 2024 and were recorded as an increase to lease liabilities when received within the Company's unaudited condensed consolidated balance sheets.