Basis of Presentation and Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2023

Schedule of Estimated Ranges of Useful Lives of Property and Equipment

Property, equipment and leasehold improvements are stated at cost less accumulated depreciation and amortization calculated using the straight-line method over their estimated useful lives as follows:


			Asset classification			Estimated useful life
			Laboratory equipment			5 years
			Computer equipment and software			3 years
			Office equipment and furniture			5 years
			Leasehold improvements			Lesser of useful life or lease term

Property and equipment, net consisted of the following (in thousands):


	December 31,
	2023		2022
Laboratory equipment(1)	$	37,216	$	39,679
Leasehold improvements	11,912		16,633
Computer equipment and software	2,565		3,039
Office equipment and furniture	1,469		1,345
Construction in progress(2)	1,636		1,739
Property and equipment	54,798		62,435
Less: accumulated depreciation and amortization	(39,311)		(39,821)
Property and equipment, net	$	15,487	$	22,614

(1) Fully depreciated property and equipment with a cost of $3.0 million and $1.5 million were retired during the years ended December 31, 2023 and 2022, respectively.

(2) Construction in progress includes equipment received but not yet placed into service pending installation.

Depreciation expense included in both research and development expenses and selling, general and administrative expenses in the consolidated statements of operations was as follows (in thousands):


	Year Ended December 31,
	2023		2022		2021
Depreciation expense	$	5,518	$	5,402	$	3,113