Lease obligation	9 Months Ended
Sep. 30, 2024
Lease obligation
Lease obligation	6. Lease obligation Operating Leases As of September 30, 2024, the Company has a lease for laboratory and office space at 75 Hayden Avenue in Lexington, Massachusetts through January 31, 2031 and a lease for additional office and laboratory space at 64 Sidney Street in Cambridge, Massachusetts (the “Cambridge Facility”) through November 30, 2026. On August 11, 2023, the Company entered into a first amendment (the “First Amendment”) to its existing lease for laboratory and office space at 75 Hayden Avenue in Lexington, Massachusetts, pursuant to which the Company agreed to lease approximately 61,307 square feet of additional office and laboratory space through January 31, 2031. The Company received $1.8 million of leasehold improvement incentives associated with the First Amendment. The Company gained control of the space on February 1, 2024 and recorded a $26.7 million right-of-use asset and a $26.7 million operating lease liability, accordingly, which reflect the leasehold improvement incentive. The Company’s lease agreements require the Company to maintain a cash deposit or irrevocable letter of credit in the aggregate amount of $2.9 million payable to its landlords as security for the performance of its obligations under the leases. These amounts are recorded as restricted cash and are included in deposits and other non-current assets in the accompanying condensed consolidated balance sheets. In June 2024, the Company vacated its leased office and laboratory space in Cambridge, Massachusetts. The Company recorded an impairment charge of $2.8 million to operating expenses during the second quarter of 2024 as a result of the carrying value of the leased office and laboratory space asset group exceeding the undiscounted cash flows projected from a planned sublease of the facility. The impairment charge reduced the carrying value of the leased office and laboratory space asset group by $2.8 million. On August 2, 2024, the Company executed the sublease of the Cambridge Facility. Payments received under the sublease are included in other income in the condensed consolidated statements of operations and comprehensive (loss) income. During the three and nine months ended September 30, 2024, the Company recognized $0.2 million of other income from its sublease of the Cambridge Facility. During the three and nine months ended September 30, 2024, the Company incurred lease expenses of $1.9 million and $8.0 million, respectively. During the three and nine months ended September 30, 2023, the Company incurred lease expenses of $0.9 million and $2.7 million, respectively, for operating leases. As of September 30, 2024, the weighted average remaining lease term was 4.9 years and the weighted average incremental borrowing rate used to determine the operating lease liability was 6.8%.

Lease obligation

9 Months Ended

Sep. 30, 2024

6. Lease obligation

Operating Leases

As of September 30, 2024, the Company has a lease for laboratory and office space at 75 Hayden Avenue in Lexington, Massachusetts through January 31, 2031 and a lease for additional office and laboratory space at 64 Sidney Street in Cambridge, Massachusetts (the “Cambridge Facility”) through November 30, 2026.

On August 11, 2023, the Company entered into a first amendment (the “First Amendment”) to its existing lease for laboratory and office space at 75 Hayden Avenue in Lexington, Massachusetts, pursuant to which the Company agreed to lease approximately 61,307 square feet of additional office and laboratory space through January 31, 2031. The Company received $1.8 million of leasehold improvement incentives associated with the First Amendment. The Company gained control of the space on February 1, 2024 and recorded a $26.7 million right-of-use asset and a $26.7 million operating lease liability, accordingly, which reflect the leasehold improvement incentive.

The Company’s lease agreements require the Company to maintain a cash deposit or irrevocable letter of credit in the aggregate amount of $2.9 million payable to its landlords as security for the performance of its obligations under the leases. These amounts are recorded as restricted cash and are included in deposits and other non-current assets in the accompanying condensed consolidated balance sheets.

In June 2024, the Company vacated its leased office and laboratory space in Cambridge, Massachusetts. The Company recorded an impairment charge of $2.8 million to operating expenses during the second quarter of 2024 as a result of the carrying value of the leased office and laboratory space asset group exceeding the undiscounted cash flows projected from a planned sublease of the facility. The impairment charge reduced the carrying value of the leased office and laboratory space asset group by $2.8 million. On August 2, 2024, the Company executed the sublease of the Cambridge Facility. Payments received under the sublease are included in other income in the condensed consolidated

statements of operations and comprehensive (loss) income. During the three and nine months ended September 30, 2024, the Company recognized $0.2 million of other income from its sublease of the Cambridge Facility.

During the three and nine months ended September 30, 2024, the Company incurred lease expenses of $1.9 million and $8.0 million, respectively. During the three and nine months ended September 30, 2023, the Company incurred lease expenses of $0.9 million and $2.7 million, respectively, for operating leases. As of September 30, 2024, the weighted average remaining lease term was 4.9 years and the weighted average incremental borrowing rate used to determine the operating lease liability was 6.8%.