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

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

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 to 5 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,
	2021		2020
Laboratory equipment (1)	$	33,101	$	25,468
Leasehold improvements	16,117		10,785
Computer equipment and software	3,481		3,192
Office equipment and furniture	1,297		1,246
Construction in progress (2)	3,231		2,357
Property and equipment	57,227		43,048
Less: accumulated depreciation and amortization	(35,882)		(33,373)
Property and equipment, net	$	21,345	$	9,675

(1) Fully depreciated property and equipment with a cost of $0.6 million and $1.8 million were retired during the years ended December 31, 2021 and 2020, 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,
	2021		2020		2019
Depreciation expense	$	3,113	$	1,950	$	1,570