Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 21,407	$ 5,585
Accounts receivable, net of allowance for doubtful accounts of $16 and $2 at December 31, 2020 and 2019, respectively	232	147
Inventory		4
Prepaid expenses and other current assets	401	642
Other receivable due from related party	618
Total current assets	22,658	6,378
Property and equipment, net	145	181
Operating lease right-of-use asset, net	567	1,065
Other assets	54	54
Total assets	23,424	7,678
Current liabilities:
Accounts payable	746	914
Accrued expenses and other current liabilities	2,205	2,561
Deferred revenue	683
Operating lease liability - current	614	528
Total current liabilities	4,248	4,003
Operating lease liability - noncurrent		614
Deferred revenue		691
Total liabilities	4,248	5,308
Commitments and contingencies (Note 15)
Stockholders’ equity:
Preferred stock, $0.001 par value, 25,000,000 shares authorized as of December 31, 2020 and 2019, respectively; no shares issued and outstanding as of December 31, 2020 and 2019
Common stock, $0.001 par value, 100,000,000 shares authorized as of December 31, 2020 and 2019, respectively; 16,297,381 and 6,825,183 shares issued and outstanding as of December 31, 2020 and 2019, respectively	16	7
Additional paid-in capital	135,234	103,433
Accumulated deficit	(116,074)	(101,070)
Total stockholders’ equity	19,176	2,370
Total liabilities and stockholders’ equity	$ 23,424	$ 7,678