Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 13,344	$ 9,899
Short-term investments	41,759	26,345
Prepaid expenses and other current assets	2,037	2,714
Total current assets	57,140	38,958
Right-of-use asset	1,799	2,349
Other assets	237	473
Total assets	59,176	41,780
Current liabilities:
Accounts payable	709	1,197
Accrued expenses	3,002	2,610
Current portion of operating lease liabilities	879	1,225
Total current liabilities	4,590	5,032
Long-term portion of operating lease liabilities	875	1,028
Total liabilities	5,465	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; 17,897,172 and 12,433,600 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively	18	12
Additional paid-in capital	285,257	259,305
Accumulated other comprehensive loss	(15)
Accumulated deficit	(231,549)	(223,597)
Total stockholders' equity	53,711	35,720
Total liabilities and stockholders' equity	$ 59,176	$ 41,780