Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 27,661	$ 25,842
Short-term investments, available-for-sale	155,174	191,492
Accounts receivable	4	1,040
Prepaid expenses and other current assets	6,271	9,764
Total current assets	189,110	228,138
Long-term investments	21,657	48,626
Property and equipment, net of accumulated depreciation	224	227
Operating lease right-of-use assets	1,482	1,964
Other long-term assets	301	386
Total assets	212,774	279,341
Current liabilities:
Accounts payable	2,851	3,034
Accrued liabilities	15,592	17,381
Total current liabilities	18,443	20,415
Line of credit commitment fee	125	250
Lease-related obligations	1,177	1,819
Total liabilities	19,745	22,484
Stockholders’ equity:
Preferred stock, $0.001 par value, 10,000,000 shares authorized at December 31, 2023 and 2022; no shares issued and outstanding as of December 31, 2023 and 2022	0	0
Common stock, $0.001 par value; 200,000,000 shares authorized at December 31, 2023 and 2022; 88,929,300 and 88,054,127 shares issued and outstanding at December 31, 2023 and 2022, respectively	89	88
Additional paid-in capital	988,457	970,535
Accumulated other comprehensive gain (loss), net	7	(337)
Accumulated deficit	(795,524)	(713,429)
Total stockholders’ equity	193,029	256,857
Total liabilities and stockholders’ equity	$ 212,774	$ 279,341