Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue:
Revenue	$ 265	$ 454	$ 3,690	$ 5,946
Operating expenses:
Research and development	4,616	3,713	11,272	11,249
General and administrative	4,190	1,455	10,076	4,856
Restructuring costs	(952)		(849)
Total operating expenses	7,854	5,168	20,499	16,105
Operating loss	(7,589)	(4,714)	(16,809)	(10,159)
Other income and (expenses):
Interest income	5	58	69	97
Interest expense		(84)		(288)
Non-cash interest expense related to sale of future royalties	(464)	(500)	(1,401)	(1,560)
Foreign exchange gain (loss), net	(11)	11	(13)	(32)
Total other income and (expenses)	(470)	(515)	(1,345)	(1,783)
Net loss before income taxes	(8,059)	(5,229)	(18,154)	(11,942)
Provision for income taxes	26	31	205	294
Net loss	$ (8,085)	$ (5,260)	$ (18,359)	$ (12,236)
Net loss per share - basic and diluted (in dollars per share)	$ (0.08)	$ (0.32)	$ (0.23)	$ (0.96)
Shares used to compute net loss per share - basic and diluted (in shares)	107,718,578	16,249,032	81,121,045	12,748,665
Customer Service Contracts [Member]
Revenue:
Revenue	$ 2	$ 94	$ 193	$ 94
Royalty [Member]
Revenue:
Revenue		8	2,962	3,736
Non Cash Royalty Revenue [Member]
Revenue:
Revenue	$ 263	$ 352	$ 535	$ 2,116