Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 210,881	$ 203,519
Marketable securities	277,481	296,326
Accounts receivable	1,371	267
Prepaid expenses and other current assets	7,298	7,198
Total current assets	497,031	507,310
Marketable securities	78,046	120,071
Property and equipment, net	17,258	17,118
Right-of-use assets	23,457	26,173
Restricted cash and other non-current assets	7,316	6,811
Total assets	623,108	677,483
Current liabilities:
Accounts payable	4,693	5,050
Accrued expenses	15,787	20,192
Deferred revenue, current	5,817	11,333
Operating lease liabilities	10,206	10,309
Total current liabilities	36,503	46,884
Operating lease liabilities, net of current portion	12,957	16,069
Deferred revenue, net of current portion	60,888	60,888
Total liabilities	110,348	123,841
Stockholders' equity
Preferred stock, $0.0001 par value per share: 5,000,000 shares authorized; no shares issued or outstanding
Common stock, $0.0001 par value per share: 195,000,000 shares authorized; 68,638,664 and 68,489,257 shares issued, and 68,602,664 and 68,435,257 shares outstanding at March 31, 2022 and December 31, 2021, respectively	7	7
Additional paid-in capital	1,423,476	1,411,827
Accumulated other comprehensive loss	(2,509)	(493)
Accumulated deficit	(908,214)	(857,699)
Total stockholders' equity	512,760	553,642
Total liabilities and stockholders' equity	$ 623,108	$ 677,483

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).