Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 60,450	$ 62,351
Short-term marketable securities	17,976	37,439
Prepaid expenses and other current assets	1,866	1,536
Total current assets	80,292	101,326
Property and equipment, net	1,979	2,164
Operating lease right-of-use assets	12,134	2,598
Other assets	1,453	1,453
Total assets	95,858	107,541
Current liabilities:
Accounts payable	4,603	7,296
Accrued expenses	5,678	8,986
Deferred revenue	4,804	4,815
Operating lease liabilities	1,150	2,219
Short-term debt	1,167	667
Other liabilities	88	87
Total current liabilities	17,490	24,070
Operating lease liabilities	11,295	677
Long-term debt, net	3,732	4,201
Other liabilities	250	275
Total liabilities	32,767	29,223
Commitments (Note 12)
Stockholders' equity
Preferred stock, $0.0001 par value; 25,000,000 shares authorized; 0 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively
Common stock, $0.0001 par value; 175,000,000 shares authorized; 48,006,049 and 45,388,023 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively	5	5
Additional paid-in capital	272,390	270,662
Accumulated other comprehensive income (loss)	(4)	25
Accumulated deficit	(209,300)	(192,374)
Total stockholders’ equity	63,091	78,318
Total liabilities and stockholders’ equity	$ 95,858	$ 107,541