8. Leases

The Company currently leases approximately 53,000 square feet of office and laboratory space in Bothell, Washington, including 13,000 square feet of space that was added in June 2025 under amended lease agreements. As part of the amended lease agreements, the Company has the right to receive tenant improvement allowances in the aggregate of up to $9.3 million for leasehold improvements, which are accounted for as lease incentives. The Bothell lease expires on March 31, 2033, and includes two five-year renewal options that are not included in the lease term as it is not reasonably certain that they will be exercised.

The Company also leased approximately 11,000 square feet of office and laboratory space in Exton, Pennsylvania. The Exton lease expired on March 31, 2025.

The Company recorded operating lease expense of $1.0 million and $0.8 million for the years ended December 31, 2025 and 2024, respectively. Under the terms of the lease agreements, the Company is also responsible for certain variable lease payments that are not included in the measurement of the lease liability. The Company incurred variable lease costs of $0.4 million for the year ended December 31, 2025. The Company did not incur significant variable lease costs for the year ended December 31, 2024.

Other information related to the Company’s operating leases was as follows:


	December 31,
	2025			2024
Weighted-average remaining lease term (in years)		7.25			8.15
Weighted-average discount rate		8.7	%		9.5	%

Supplemental cash flow information related to the Company’s operating leases was as follows (in thousands):


	Year Ended December 31,
	2025		2024
Cash paid for operating lease liabilities	$	705	$	337

The Company’s future minimum lease payments were as follows as of December 31, 2025 (in thousands):


Years ending December 31,	Amount
2026	$	1,468
2027		2,330
2028		2,383
2029		2,437
2030 and thereafter		8,312
Total lease payments		16,930
Less: imputed interest		(3,737	)
Less: tenant improvement allowance not yet received		(9,338	)
Present value of operating lease liabilities	$	3,855