Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 44,629	$ 24,609
Restricted cash	115
Short-term investments	54,376	35,166
Prepaid expenses and other current assets	5,086	2,556
Total current assets	104,206	62,331
Property and equipment, net	259	281
Right-of-use asset, net	608	716
Other assets	82	197
Total assets	105,155	63,525
Current liabilities:
Accounts payable	8,998	6,178
Accrued expenses and other current liabilities	7,795	10,195
Current portion of deferred revenue	1,517	1,517
Current portion of right-of-use liability	480	478
Total current liabilities	18,790	18,368
Long-term liabilities:
Deferred revenue, less current portion	12,754	13,133
Right-of-use liability, less current portion	306	419
Loan payable	19,792
Other long-term liabilities	4	5
Total long-term liabilities	32,856	13,557
Total liabilities	51,646	31,925
Commitments
Stockholders’ equity:
Preferred stock, $0.001 par value, 10,000,000 shares authorized; 0 shares outstanding at March 31, 2020 and December 31, 2019
Common stock, $0.0001 par value, 100,000,000 shares authorized; 30,240,838 and 27,140,484 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively	3	3
Additional paid-in capital	564,164	527,067
Accumulated other comprehensive income	48
Accumulated deficit	(510,706)	(495,470)
Total stockholders’ equity	53,509	31,600
Total liabilities and stockholders’ equity	$ 105,155	$ 63,525