Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 136,379	$ 144,514
Prepaid expenses and other current assets	3,904	2,591
Total current assets	140,283	147,105
Property and equipment, net	2,142	2,243
Operating lease, right-of-use ("ROU") asset	3,819	4,089
Other assets	320	320
Total assets	146,564	153,757
Current liabilities:
Accounts payable	257	867
Accrued expenses	8,050	8,775
Operating lease obligations, current portion	1,027	989
Total current liabilities	9,334	10,631
Operating lease obligations, long-term portion	2,740	3,048
Total liabilities	12,074	13,679
Commitments and contingencies (Note 6)
Stockholders' equity:
Preferred stock, $0.0001 par value; 10,000 shares authorized and no shares issued and outstanding as of March 31, 2022 and December 31, 2021	0	0
Common stock, $0.0001 par value: 300,000 shares authorized; 101,286 and 101,303 shares issued at March 31, 2022 and December 31, 2021, respectively; 100,905 and 100,832 shares outstanding at March 31, 2022 and December 31, 2021, respectively	10	10
Additional paid-in-capital	375,231	373,657
Accumulated deficit	(240,751)	(233,589)
Total stockholders' equity	134,490	140,078
Total liabilities and stockholders' equity	$ 146,564	$ 153,757