Consolidated Statements of Operations and Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue:
Revenue	$ 4,046,000	$ 9,862,000	$ 4,159,000
Operating expenses:
Research and development	19,863,000	14,540,000	17,275,000
General and administrative	15,202,000	6,187,000	6,681,000
Impairment of intangible assets			1,600,000
Costs of exit from leased premises			359,000
Restructuring charges and (reversals)	(849,000)	4,920,000
Total operating expenses	34,216,000	25,647,000	25,915,000
Operating loss	(30,170,000)	(15,785,000)	(21,756,000)
Other income and (expenses):
Bargain purchase gain			6,760,000
Interest income	75,000	149,000	58,000
Interest expense		(315,000)	(821,000)
Non-cash interest expense related to sale of future royalties	(1,874,000)	(2,073,000)	(1,859,000)
Gain (loss) on sale of equipment		1,000	(11,000)
Loss on revaluation of financial instruments			(3,000)
Loss on debt extinguishment		(100,000)
Foreign exchange loss, net	(13,000)	(32,000)	(266,000)
Loss before provision for income taxes	(31,982,000)	(18,155,000)	(17,898,000)
Provision for income taxes	238,000	490,000	109,000
Net loss	(32,220,000)	(18,645,000)	(18,007,000)
Series B and C preferred dividend			(339,000)
Net comprehensive loss attributable to common stockholders	$ (32,220,000)	$ (18,645,000)	$ (18,346,000)
Net loss per share – basic and diluted (in dollars per share)	$ (0.36)	$ (0.86)	$ (2.90)
Shares used to compute net loss per share – basic and diluted (in shares)	88,295,762	21,569,523	6,316,065
Customer Service Contracts [Member]
Revenue:
Revenue	$ 198,000	$ 406,000
Government Contract [Member]
Revenue:
Revenue		(20,000)	1,344,000
Royalty [Member]
Revenue:
Revenue	2,962,000	4,446,000	1,340,000
Non Cash Royalty Revenue [Member]
Revenue:
Revenue	$ 886,000	$ 5,030,000	$ 1,475,000