Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 101,136	$ 92,795
Marketable securities	53,153	92,975
Collaboration receivable	300,000	0
Prepaid expenses and other current assets	5,273	4,917
Total current assets	459,562	190,687
Property and equipment, net	17,563	19,528
Restricted cash	1,733	1,733
Other assets	2,400	842
Operating lease right-of-use assets	38,516	42,804
Total assets	519,774	255,594
Current liabilities:
Accounts payable	3,819	3,680
Accrued expenses and other current liabilities	9,562	9,161
Operating lease liabilities	6,994	3,981
Deferred revenue	28,317	2,024
Total current liabilities	48,692	18,846
Notes payable, net of discount	0	19,654
Operating lease liabilities, net of current portion	51,338	58,361
Deferred revenue, net of current portion	322,730	12,546
Other liabilities	143	0
Total liabilities	422,903	109,407
Commitments and contingencies (Note 13)
Stockholders’ equity:
Preferred stock, $0.0001 par value; 25,000,000 shares authorized as of December 31, 2021 and 2020; no shares issued or outstanding	0	0
Common stock, $0.0001 par value; 175,000,000 shares authorized at December 31, 2021 and 2020; 41,299,720 shares issued and outstanding at December 31, 2021 and 36,790,946 shares issued and outstanding at December 31, 2020	4	4
Additional paid-in capital	361,133	309,126
Accumulated other comprehensive loss	(10)	(7)
Accumulated deficit	(264,256)	(162,936)
Total stockholders’ equity	96,871	146,187
Total liabilities and stockholders’ equity	$ 519,774	$ 255,594