Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 139,520	$ 24,930
Short-term investments		20,000
Prepaid expenses and other current assets	532	1,395
Total current assets	140,052	46,325
Right-of-use asset	717	966
Other assets	176	165
Total assets	140,945	47,456
Current liabilities:
Accounts payable	619	1,544
Accrued expenses	2,714	4,197
Current portion of operating lease liabilities	655	649
Total current liabilities	3,988	6,390
Long-term portion of operating lease liabilities	58	397
Total liabilities	4,046	6,787
Commitments
Stockholders' equity:
Common stock, $0.001 par value per share, 150,000,000 shares authorized; 76,948,803 and 20,084,337 shares issued and outstanding at June 30, 2021 and December 31, 2020, respectively	77	20
Additional paid-in capital	475,499	301,546
Accumulated deficit	(438,447)	(260,897)
Total stockholders' equity	136,899	40,669
Total liabilities and stockholders' equity	140,945	$ 47,456
Series X redeemable convertible preferred stock
Stockholders' equity:
Preferred stock, value	$ 99,770