CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating expenses:
Research and development	$ 21,830	$ 22,503
General and administrative	8,921	9,849
Total operating expenses	30,751	32,352
Loss from operations	(30,751)	(32,352)
Interest income	447	170
Interest expense	(19)	(528)
Interest expense - related party		(121)
Australian research and development incentives	756	1,715
Foreign currency gains (loss)	(835)	759
Change in fair value of warrant liability	7,284	473
Loss before income taxes	(23,118)	(29,884)
Income taxes	(20)	157
Net loss	(23,138)	(29,727)
Accretion of preferred stock to redemption value		(244)
Net loss attributable to common stockholders	$ (23,138)	$ (29,971)
Net loss per share
Basic (in dollars per share)	$ (1.64)	$ (3.27)
Diluted (in dollars per share)	$ (2.11)	$ (3.31)
Weighted average common shares outstanding
Basic (in shares)	14,144,287	9,161,844
Diluted (in shares)	14,412,695	9,188,587