Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 25,445	$ 46,989
Short-term investments, available-for-sale	106,584	31,973
Accounts receivable	36	340
Prepaid expenses and other current assets	4,185	2,356
Total current assets	136,250	81,658
Long-term investments	7,535	0
Property and equipment, net of accumulated depreciation	298	214
Operating lease right-of-use assets	2,612	2,825
Other long-term assets	30	26
Total assets	146,725	84,723
Current liabilities:
Accounts payable	1,457	1,283
Accrued liabilities	9,465	7,250
Note payable	14,000	0
Total current liabilities	24,922	8,533
Lease-related obligations	2,654	2,814
Total liabilities	27,576	11,347
Stockholders’ equity:
Preferred stock, $0.001 par value, 10,000,000 shares authorized at June 30, 2021 and December 31, 2020; no shares issued and outstanding as of June 30, 2021 and December 31, 2020	0	0
Common stock, $0.001 par value, 200,000,000 shares authorized at June 30, 2021 and December 31, 2020; 86,249,744 and 62,816,039 shares issued and outstanding as of June 30, 2021 and December 31, 2020, respectively	86	63
Additional paid-in capital	946,612	785,673
Accumulated other comprehensive loss, net	(11)	0
Accumulated deficit	(827,538)	(712,360)
Total stockholders’ equity	119,149	73,376
Total liabilities and stockholders’ equity	$ 146,725	$ 84,723