Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 24,237	$ 25,096
Accounts receivable	1,660
Prepaid expenses & other current assets	2,450	244
Total current assets	28,347	25,340
Property and equipment, net	1,271	750
Intangible assets, net	38	43
Equity method investment	960
Other assets	995	345
Total assets	31,611	26,478
Current liabilities:
Accounts payable	2,331	933
Accrued liabilities	2,944	2,121
Deferred revenue	22	120
Total current liabilities	5,297	3,174
Warrant liability		11,868
Total liabilities	5,297	15,042
Total convertible preferred stock		74,202
Commitments and contingencies (Note 12)
Stockholders' equity (deficit):
Common stock (par value, $0.0001 per share; shares authorized: 100,000,000 and 100,000,000 , respectively; shares issued and outstanding: 8,104,757 and 166,373, as of December 31, 2018 and 2017, respectively )	1
Additional paid-in capital	97,401	(15,140)
Accumulated deficit	(71,088)	(47,626)
Total stockholders' equity (deficit)	26,314	(62,766)
Total liabilities, convertible preferred stock and stockholders' equity (deficit)	$ 31,611	26,478
Series A Convertible Preferred Stock
Current liabilities:
Total convertible preferred stock		$ 74,202