CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 36,103	$ 24,846
Short-term investments	0	1,999
Accounts receivable	4	108
Prepaid expenses and other current assets	2,234	2,786
Total current assets	38,341	29,739
Property and equipment, net	443	523
Operating lease right-of-use asset, net	266
Total assets	39,050	30,262
Current liabilities:
Accounts payable	1,629	1,096
Accrued liabilities	3,055	5,108
Current portion of note payable	3,977	3,976
Total current liabilities	8,661	10,180
Note payable, net of current portion	3,389	4,328
Total liabilities	12,050	14,508
Commitments and contingencies
Stockholders’ equity:
Common stock, $0.01 par value; 100,000,000 shares authorized; 53,077,348 and 34,861,876 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively	531	349
Additional paid-in capital	202,685	183,574
Accumulated deficit	(176,216)	(168,169)
Total stockholders’ equity	27,000	15,754
Total liabilities and stockholders’ equity	$ 39,050	$ 30,262