CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($)	Sep. 30, 2021	Dec. 31, 2020	[1]
Current assets:
Cash and cash equivalents	$ 145,826,000	$ 147,017,000
Short-term marketable securities	237,603,000	148,139,000
Related party receivable from collaboration	4,400,000	333,000
Related party contract asset	0	6,100,000
Prepaid expenses and other current assets	8,054,000	6,837,000
Total current assets	395,883,000	308,426,000
Property and equipment, net	11,452,000	14,526,000
Restricted cash	1,499,000	1,499,000
Other non-current assets	7,024,000	4,592,000
Total assets	415,858,000	329,043,000
Current liabilities:
Accounts payable	7,632,000	9,663,000
Accrued liabilities	34,720,000	29,945,000
Deferred rent, current	3,088,000	2,975,000
Contract liabilities	12,288,000	0
Total current liabilities	57,728,000	42,583,000
Deferred rent, non-current	4,091,000	6,417,000
Total liabilities	61,819,000	49,000,000
Commitments and contingencies (Note 6)
Stockholders' equity:
Preferred stock, $0.001 par value; 10,000,000 shares authorized; no shares issued or outstanding as of September 30, 2021 and December 31, 2020, respectively	0	0
Common stock, $0.001 par value; 400,000,000 shares authorized; 77,642,628 and 70,585,364 shares issued and outstanding as of September 30, 2021 and December 31, 2020, respectively	78,000	71,000
Additional paid-in capital	745,704,000	578,599,000
Accumulated other comprehensive (loss) income	(11,000)	4,000
Accumulated deficit	(391,732,000)	(298,631,000)
Total stockholders' equity	354,039,000	280,043,000
Total liabilities and stockholders' equity	$ 415,858,000	$ 329,043,000

[1] The condensed consolidated balance sheet as of December 31, 2020 has been derived from the audited financial statements as of that date.