X4 Pharmaceuticals, IncXFOR

X4 Pharmaceuticals, Inc Leases Disclosure

10-KFiled Mar 17, 20262 min read
Leases
The Company has a lease agreement for its facilities in Boston, Massachusetts, which is the Company’s principal executive offices, and previously had a lease in Vienna, Austria (the “Vienna Lease”), which was previously the Company’s research and development center. There are no restrictions or financial covenants associated with any of the lease agreements.
Boston Lease— The Company leases approximately 28,000 square feet of office space in Boston, Massachusetts (“Boston Lease”), which serves as the Company’s headquarters. Base rental payments are approximately $1.1 million annually, plus certain operating expenses. The term of the Boston Lease will continue until November 2026, unless earlier terminated. The Company is required to maintain a security deposit in the form of a letter of credit for $0.6 million for the benefit of the landlord.
Vienna Austria Lease— The Company had an operating lease for approximately 1,200 square meters of laboratory and office space in Vienna, Austria that commenced in February 2021 for a term of seven years. Effective November 30, 2025, the Company terminated the Vienna Lease in accordance with a lease amendment entered into with the landlord. Accordingly, the Company accelerated the amortization of the right-of-use asset to zero and adjusted the remaining lease obligation to zero as of December 31, 2025.

The components of lease expense for the years ended December 31, 2025, 2024 and 2023 were as follows:
(dollars in thousands)
Year Ended December 31,
Lease Cost202520242023
Fixed operating lease cost$2,120$1,953$2,084 
Total lease expense$2,120$1,953$2,084 
Other information
Sublease income$— $— $195 
Operating cash outflows from operating leases$1,398$1,377$1,385 
Weighted-average remaining lease term0.9 years2.3 years3.2 years
Weighted-average discount rate11.5 %11.5 %11.5 %


Maturities of lease liabilities due under lease agreements as of December 31, 2025 are as follows (in thousands):
Maturity of lease liabilitiesOperating
Leases
2026$1,052 
Total lease payments1,052 
Less: interest(58)
Total operating lease liabilities as of December 31, 2025$994 

Historical Timeline

Fiscal YearFiled
2025Mar 17, 2026Showing above
2024Mar 26, 2025
2023Mar 21, 2024
2022Mar 21, 2023
2021Mar 17, 2022
2020Mar 19, 2021
2019Mar 12, 2020

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.

Other Available Disclosures

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