12. Operating Leases

Leases classified as operating leases are included in operating lease ROU, operating lease liabilities, current portion and operating lease liabilities, net of current portion, in the Company's consolidated balance sheets.

The Company leases its office and facilities in Boston, Massachusetts under a non-cancellable operating lease agreement that continues through December 31, 2032. Under the terms of the lease agreement, the Company is responsible for certain insurance, property taxes and maintenance expenses, which represents the Company’s proportionate share of the actual expenses incurred by the landlord. The operating lease agreement contains scheduled annual rent increases over the lease term.

The Company subleases approximately 17,729 square feet of office and laboratory space in the building located at 321 Harrison Avenue, Boston, Massachusetts. The Company remains jointly and severally liable under the head lease and accounts for the sublease as an operating lease. The lease term commenced on March 24, 2023, and is expected to end in May 2026. The Company recognized sublease income of $2.6 million and $2.9 million for the years ended December 31, 2025 and 2024, respectively.

The components of lease expense were as follows (in thousands):

Year Ended December 31,

 

2025

 

 

2024

 

Lease cost

 

 

 

 

 

Operating lease cost

$

2,653

 

 

$

2,653

 

Variable lease cost

 

1,047

 

 

 

1,737

 

Short-term lease cost

 

21

 

 

 

27

 

Total operating lease cost

$

3,721

 

 

$

4,417

 

 

Other information

 

 

 

 

 

Cash paid for amounts included in the measurement of lease liabilities, included in operating cash flows

$

3,359

 

 

$

3,295

 

Weighted-average remaining lease term (in years)

 

7.0

 

 

 

8.0

 

Weighted-average discount rate

 

9.4

%

 

 

9.4

%

 

Variable lease costs primarily relate to common area costs and other operating costs, which are assessed based on the Company’s proportionate share of such costs for the leased premises. Total lease costs are included as operating expenses in the Company’s consolidated statements of operations and comprehensive loss.

Maturities of lease liabilities for the next five years, as of December 31, 2025, are as follows (in thousands):

Years Ending December 31,

Operating Lease Payments

 

 

Sublease Receipts

 

 

Net Operating Lease Payments

 

2026

$

3,375

 

 

$

738

 

 

$

2,637

 

2027

 

3,473

 

 

 

 

 

 

3,473

 

2028

 

3,575

 

 

 

 

 

 

3,575

 

2029

 

3,680

 

 

 

 

 

 

3,680

 

2030

 

3,788

 

 

 

 

 

 

3,788

 

Thereafter

 

7,916

 

 

 

 

 

 

7,916

 

Total undiscounted payments

 

25,807

 

 

$

738

 

 

$

25,069

 

Less: present value adjustment

 

(7,157

)

 

 

 

 

 

 

Present value of future payments

 

18,650

 

 

 

 

 

 

 

Less: current portion of operating lease liabilities

 

(1,692

)

 

 

 

 

 

 

Operating lease liabilities, net of current portion

$

16,958

 

 

 

 

 

 

 

Historical Timeline

Fiscal YearFiled
2025Mar 23, 2026Showing above
2024Mar 18, 2025
2023Mar 21, 2024
2022Mar 22, 2023
2021Mar 29, 2022

About Leases Disclosures

Lease disclosures under ASC 842 provide a comprehensive view of a company's leased asset portfolio, including the split between operating and finance leases, discount rates used to present-value future payments, and the maturity schedule of lease obligations. This section reveals a significant source of off-balance-sheet commitments that were largely hidden before the current standard.

Key signals: the weighted-average discount rate affects the size of recorded lease liabilities — a higher rate reduces the reported obligation, so compare the chosen rate against the company's incremental borrowing rate. The operating versus finance lease mix affects both EBITDA and operating income presentation. Watch the maturity table for concentration risk: large payment cliffs in specific years may create cash flow pressure. Variable lease payments excluded from the liability measurement represent real obligations that do not appear on the balance sheet. Compare total lease costs against prior-year operating lease expense to assess the true economic burden.