Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 27,893	$ 14,437
Accounts receivable	919	905
Inventories	2,957	2,957
Other current assets	369	237
Total current assets	32,138	18,536
Property, plant and equipment, net	1,219	1,200
Operating lease right-of-use asset, net	206	255
Other assets	0	21
TOTAL ASSETS	33,563	20,012
Current liabilities
Accounts payable	1,613	1,097
Accrued compensation	1,245	2,192
Current portion of operating lease liability	212	206
Current portion of finance lease liability	24	24
Other current liabilities	69	66
Total current liabilities	3,163	3,585
Operating lease liability	0	55
Finance lease liability	48	54
Total liabilities	3,211	3,694
Commitments and contingencies
Stockholders' equity
Preferred stock	0	0
Common stock as of March 31, 2021 and December 31, 2020, par value $0.0001 per share; authorized 100,000,000 shares, issued and outstanding 6,531,942 and 2,736,060, respectively	0	0
Additional paid-in capital	268,921	249,663
Accumulated other comprehensive loss:
Foreign currency translation adjustment	(10)	(7)
Accumulated deficit	(238,559)	(233,338)
Total stockholders' equity	30,352	16,318
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	33,563	20,012
Series A Junior Participating Preferred Stock [Member]
Stockholders' equity
Preferred stock	0	0
Series F Convertible Preferred Stock [Member]
Stockholders' equity
Preferred stock	$ 0	$ 0