Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net loss	$ (2,843)	$ (8,886)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	20	106
Stock-based compensation	19	279
Non-cash lease expense	16	3
Restructuring charges-inventory and fixed asset impairment		1,115
Changes in operating assets and liabilities:
Accounts receivable		455
Inventories		(112)
Prepaid expenses and other assets	332	(610)
Accounts payable	1,158	497
Accrued expenses	345	286
Accrued compensation expenses	26	(1,813)
Accrued clinical trial expenses	149	26
Net cash used in operating activities	(778)	(8,654)
Cash flows from investing activities:
Purchases of property and equipment		(331)
Net cash used in investing activities		(331)
Cash flows from financing activities:
Net proceeds from sale of common stock and/or warrants	24,466	6
Repurchase of fractional shares in connection with reverse stock split		(11)
Net cash provided by (used in) financing activities	24,466	(5)
Effect of exchange rate changes on cash and cash equivalents	(3)	2
Cash and cash equivalents:
Net increase (decrease)	23,685	(8,988)
Balance at beginning of period	3,177	11,327
Balance at end of period	$ 26,862	$ 2,339