Leases

12 Months Ended

Dec. 31, 2023

Leases

Leases

11. Leases

The Company has operating leases for office space and laboratory facilities. The components of lease expense were as follows:

	Year Ended
	December 31,
(In thousands)	2023		2022		2021
Operating lease expense	$	1,092	$	1,013	$	1,013

Rent expense was $1.1 million for the year ended December 31, 2023, and $1.0 million for each of the years ended December 31, 2022 and 2021, which was recognized on a straight-line basis over the term of the lease.

Operating Leases

Agreements for Office and Laboratory Space

The Company had a sublease agreement pursuant to which it subleased 33,019 square feet of office space for its headquarters in Wayne, Pennsylvania, which expired on October 31, 2023. In December 2020, the Company entered into a sub-sublease agreement under which it sub-subleased 8,115 square feet to a third party. The sub-sublease was terminated in December 2022.

In May 2023, the Company entered into a new lease agreement pursuant to which it leases 11,564 square feet of office space for its headquarters in Wayne, Pennsylvania. The lease commenced on November 1, 2023 and has a term that runs through February 2029.

In February 2019, the Company entered into a sublease agreement for 20,433 square feet of office and laboratory space in St. Louis, Missouri. The lease commenced in June 2019 and has a term that runs through June 2029. In January 2023, the Company amended the sublease agreement to add an additional 6,261 square feet of office and laboratory space effective February 2023, which term runs concurrently with the existing term.

Supplemental balance sheet information related to operating leases is as follows:  

		December 31,		December 31,
(In thousands)	2023		2022
Operating Leases:
Gross cost	$	5,094	$	5,240
Accumulated amortization		(1,235)		(2,560)
Other assets	$	3,859	$	2,680
Current portion of lease liabilities	$	426	$	684
Other liabilities		3,074		1,570
Total operating lease liabilities	$	3,500	$	2,254

Amortization expense related to operating lease right-of-use assets and accretion of operating lease liabilities totaled $0.8 million for the year ended December 31, 2023, and $1.0 million for each of the years ended December 31, 2022 and 2021.

Supplemental information related to operating leases is as follows:

	Year Ended
(In thousands, except for years and percentages)	December 31,
Supplemental Cash Flow Lease Information:	2023			2022			2021
Operating cash flows from operating leases	$	974		$	846		$	924
Leased assets obtained in exchange for new operating lease liabilities	$	2,010		$	—		$	—
Weighted-Average Remaining Lease Term (in years):
Operating leases		5.3			5.2			5.4
Weighted-Average Discount Rate:
Operating leases		10.2	%		10.1	%		10.1	%

Future minimum lease payments under operating lease agreements are as follows:

(In thousands)		Operating
Year Ending December 31,		Leases
2024	$	766
2025		847
2026		868
2027		890
2028		912
Thereafter		316
Total undiscounted lease payments		4,598
Less: unrecognized interest		(1,098)
Total lease liability	$	3,500