Restructuring, Impairment and Costs of Terminated Program (Tables)

12 Months Ended

Dec. 31, 2023

Restructuring and Related Activities [Abstract]

Schedule of Restructuring, Impairment and Costs of Terminated Program

Restructuring, impairment and costs of terminated program includes the following (in thousands):

	Year Ended December 31,
	2023						2022
	2022 Restructuring Plan		2023 Restructuring Plan		Total		2022 Restructuring Plan
Clinical trial expense, other third-party and employee costs for the wind down of the bempegaldesleukin program	$	5,492	$	—	$	5,492	$	31,693
Severance and benefit expense		—		7,885		7,885		30,904
Impairment of right-of-use assets and property, plant and equipment		14,728		20,600		35,328		65,761
Loss (gain) on sale or disposal of other property, plant and equipment, net		—		1,300		1,300		(3,326	)
Contract termination and other restructuring costs		1,919		34		1,953		10,898
Restructuring, impairment and costs of terminated program	$	22,139	$	29,819	$	51,958	$	135,930

The following table provides details regarding the severance and benefit expense for the years ended December 31, 2023 and 2022 pursuant to the 2022 and 2023 Restructuring Plans and a reconciliation of the severance and benefits liability for the year ended December 31, 2023 pursuant to the 2022 and 2023 Restructuring Plans, which we report within accrued expenses on our Consolidated Balance Sheets (in thousands):

	2023 Restructuring Plan			2022 Restructuring Plan			Total
Liability balance as of December 31, 2021	$	—		$	—		$	—
Expense recognized during the period		—			30,904			30,904
Payments during the period		—			(27,605	)		(27,605	)
Liability balance as of December 31, 2022	$	—		$	3,299		$	3,299
Expense recognized during the period		7,885			—			7,885
Payments during the period		(7,689	)		(3,299	)		(10,988	)
Liability balance as of December 31, 2023	$	196		$	—		$	196

We recorded non-cash impairment charges of lease assets pertaining to the 2022 and 2023 Restructuring Plans as follows (in thousands):

	Three-months Ended
Sublease Spaces	June 30, 2022		September 30, 2022		December 31, 2022		March 31, 2023		June 30, 2023		September 30, 2023		December 31, 2023		Total
Mission Bay Blvd. South	$	3,000	$	1,200	$	361	$	—	$	7,061	$	1,467	$	—	$	13,089
Third St		49,200		—		12,000		—		6,200		—		—		67,400
Total 2022 Restructuring Plan		52,200		1,200		12,361		—		13,261		1,467		—		80,489
Mission Bay Blvd. South - 2023 Restructuring Plan	N/A		N/A		N/A			11,500		—		9,100		—		20,600
Total impairment of lease assets	$	52,200	$	1,200	$	12,361	$	11,500	$	13,261	$	10,567	$	—	$	101,089

The following are reconciliations of the impairment charges we recorded for the years ended December 31, 2023 and 2022, including the net book values of the sublease assets before the impairment and the fair values of the sublease assets. Since we recorded multiple impairment charges for certain spaces as a resulting of worsening lease markets, we present the net book value before the first impairment in such year and the fair value after the second impairment in such year (in thousands):

	Year Ended December 31, 2022
	Operating Lease			Property, Plant and
	Right-of-Use Assets			Equipment			Total
Net book value of impaired sublease assets	$	72,481		$	16,348		$	88,829
Less: Fair value of impaired sublease assets — Level 3 of Fair Value Hierarchy		(16,174	)		(4,780	)		(20,954	)
Book value in excess of fair value		56,307			11,568			67,875
Less: Amounts recorded as amortization between June 30, 2022 and December 31, 2022 for Third St. facility		(1,717	)		(397	)		(2,114	)
Total impairment of sublease assets	$	54,590		$	11,171		$	65,761

	Year Ended December 31, 2023
	Operating Lease Right-of-Use Assets			Property, Plant and Equipment			Total
Net book value of impaired facilities before write-off	$	46,292		$	7,206		$	53,498
Less: Fair value of impaired facilities — Level 3 of Fair Value Hierarchy		(14,364	)		(2,172	)		(16,536	)
Book value in excess of fair value		31,928			5,034			36,962
Less: Amounts recorded as amortization between March 31, 2023 and September 30, 2023 for Mission Bay facility		(1,371	)		(263	)		(1,634	)
Total impairment of right-of-use assets and property, plant and equipment	$	30,557		$	4,771		$	35,328

The following is a reconciliation of the contract termination and other costs for the 2022 Restructuring Plan and the related liability of which we report $3.0 million within accrued expenses and the remaining within other long-term liabilities on our Consolidated Balance Sheet as of December 31, 2023:

	Year Ended
	December 31, 2023
Liability balance as of December 31, 2021	$	—
Expense recognized during the period		10,898
Payments during the period		(3,188	)
Liability balance as of December 31, 2022		7,710
Expense recognized during the period		1,919
Payments during the period		(4,087	)
Liability balance as of December 31, 2023	$	5,542

Schedule of Property, Plant and Equipment

Property, Plant and Equipment

Property, plant and equipment consists of the following (in thousands):

	December 31,
	2023			2022
Building and leasehold improvements	$	43,184		$	74,889
Laboratory equipment		14,537			24,243
Computer equipment and software		22,438			26,205
Manufacturing equipment		24,315			25,052
Furniture, fixtures, and other		541			4,263
Depreciable property, plant and equipment at cost		105,015			154,652
Less: accumulated depreciation		(86,898	)		(124,731	)
Depreciable property, plant and equipment, net		18,117			29,921
Construction-in-progress		739			2,530
Property, plant and equipment, net	$	18,856		$	32,451

We recorded the gains and losses as follows (in thousands):

	Year Ended December 31,
	2023		2022
Proceeds from sales	$	1,245	$	13,196
Net book value of assets		2,545		9,870
Total (gain) loss on sale or disposal of other property, plant and equipment, net	$	1,300	$	(3,326	)