CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net loss	$ (19,711)	$ (26,558)	$ (7,967)
Adjustments to reconcile net loss to cash used in operating activities:
Impairment of intangible assets	176	1,142	0
Impairment of Panacea investment	1,741
Amortization and depreciation	1,094	1,186	1,200
Amortization of license fees	251	239	143
Amortization of ROU assets	182	212
Realized gain on the sale of investments			(14,493)
Unrealized (gain) loss on investment	434	2,419	(284)
Realized (gain) loss on short-term investment securities	(5)	(221)	54
Litigation settlement		1,891
Gain on the sale of machinery and equipment	(1)	(87)
Warrant liability (gain) loss			(49)
Accretion of non cash interest expense	43	48	11
Accretion of non-cash interest income	(369)	(22)
Equity-based employee compensation expense	1,654	3,540	3,187
Inventory write-off	521	985
(Decrease) increase in inventory reserve			(95)
(Increase) decrease in assets:
Accounts receivable	(1,292)	4	86
Inventory	(289)	(207)	334
Prepaid expenses and other assets	(787)	280	(182)
Increase (decrease) in liabilities:
Operating lease obligations	(552)	(212)
Accounts payable	(936)	(732)	322
Accrued expenses	2,183	792	(167)
Accrued severance	(225)	792
Deferred income	267	(78)	55
Net cash provided by (used in) operating activities	(15,621)	(14,588)	(17,845)
Cash flows from investing activities:
Acquisition of patents and trademarks	(468)	(565)	(657)
Acquisition of machinery and equipment	(54)	(527)	(449)
Proceeds from the sale of machinery and equipment	6	166
Investment in Panacea		(12,000)
Proceeds from sale of investments			13,052
Sales and maturities of short-term investment securities	39,728	19,320	37,415
Purchase of short-term investment securities	(22,743)	(1,842)	(34,216)
Net cash provided by investing activities	16,469	4,552	15,145
Cash flows from financing activities:
Payment on note payable	(2,549)	(700)	(800)
Proceeds from note payable issuance	2,195
Proceeds from exercise of stock options	50		445
Net proceeds from exercise of stock warrants		10,616
Proceeds from SBA loan	1,183
Repayment of SBA loan	(1,183)
Net cash used in financing activities	(304)	9,916	(355)
Net increase (decrease) in cash and cash equivalents	544	(120)	(3,055)
Cash and cash equivalents - beginning of period	485	605	3,660
Cash and cash equivalents - end of period	1,029	485	605
Net cash paid for:
Cash paid during the period for interest	29	3
Non-cash transactions:
Patent and trademark additions included in accounts payable	55	155	152
Machinery and equipment additions included in accounts payable	2		19
Right-of-use assets and corresponding operating lease obligations	198	814
Patent and trademark additions included in accrued expenses	$ 28
Licenses acquired with notes payable			2,326
Reclassification of warrant liability to capital in excess of par			$ 168
Stock issued in connection with investment		$ 1,297