Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 52,856	$ 9,899
Short-term investments		26,345
Prepaid expenses and other current assets	2,656	2,714
Total current assets	55,512	38,958
Right-of-use asset	1,178	2,349
Other assets	160	473
Total assets	56,850	41,780
Current liabilities:
Accounts payable	1,408	1,197
Accrued expenses	4,924	2,610
Current portion of operating lease liabilities	648	1,225
Total current liabilities	6,980	5,032
Long-term portion of operating lease liabilities	559	1,028
Total liabilities	7,539	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; 20,077,337 and 12,433,600 shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively	20	12
Additional paid-in capital	301,210	259,305
Accumulated deficit	(251,919)	(223,597)
Total stockholders' equity	49,311	35,720
Total liabilities and stockholders' equity	$ 56,850	$ 41,780