Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue:
Revenue from Contract with Customer, Including Assessed Tax	$ 85	$ 608	$ 5,492	$ 2,111
Operating expenses:
Research and development	3,707	5,012	7,536	8,420
General and administrative	1,375	1,771	3,401	3,781
Impairment of intangible assets		1,600		1,600
Total operating expenses	5,082	8,383	10,937	13,801
Operating loss	(4,997)	(7,775)	(5,445)	(11,690)
Other income and (expenses):
Bargain purchase gain		(328)		6,660
Interest income	34	36	39	41
Interest expense	(97)	(136)	(204)	(573)
Non-cash interest expense related to sale of future royalties	(516)	(468)	(1,060)	(766)
Loss on revaluation of financial instruments				(3)
Foreign exchange gain, net	(48)	(199)	(43)	(197)
Total other income and (expenses)	(627)	(1,095)	(1,268)	5,162
Net loss before income taxes	(5,624)	(8,870)	(6,713)	(6,528)
Provision for income taxes	13	1	263	29
Net loss	(5,637)	(8,871)	(6,976)	(6,557)
Series B and C preferred dividend				(339)
Net comprehensive loss attributable to common stockholders	$ (5,637)	$ (8,871)	$ (6,976)	$ (6,896)
Net loss per share - basic and diluted (in dollars per share)	$ (0.39)	$ (1.24)	$ (0.64)	$ (1.26)
Shares used to compute net loss per share - basic and diluted (in shares)	14,597,446	7,141,189	10,969,473	5,477,265
Government Contract [Member]
Revenue:
Revenue from Contract with Customer, Including Assessed Tax		$ 520		$ 1,130
Royalty [Member]
Revenue:
Revenue from Contract with Customer, Including Assessed Tax	69	70	3,728	963
Non Cash Royalty Revenue [Member]
Revenue:
Revenue from Contract with Customer, Including Assessed Tax	$ 16	$ 18	$ 1,764	$ 18