Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 24,930	$ 9,899
Short-term investments	20,000	26,345
Prepaid expenses and other current assets	1,395	2,714
Total current assets	46,325	38,958
Right-of-use asset	966	2,349
Other assets	165	473
Total assets	47,456	41,780
Current liabilities:
Accounts payable	1,544	1,197
Accrued expenses	4,197	2,610
Current portion of operating lease liabilities	649	1,225
Total current liabilities	6,390	5,032
Long-term portion of operating lease liabilities	397	1,028
Total liabilities	6,787	6,060
Commitments (Note 6)
Stockholders' equity:
Preferred stock, $0.001 par value per share, 5,000,000 shares authorized and no shares issued and outstanding
Common stock, $0.001 par value per share, 150,000,000 shares authorized; 20,084,337 and 12,433,600 shares issued and outstanding at December 31, 2020 and December 31, 2019, respectively	20	12
Additional paid-in capital	301,546	259,305
Accumulated deficit	(260,897)	(223,597)
Total stockholders' equity	40,669	35,720
Total liabilities and stockholders' equity	$ 47,456	$ 41,780