CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME
Revenue			$ 0
Operating expenses:
Research and development	$ 8,061	$ 4,778	26,185	$ 13,057
General and administrative	3,173	1,164	8,947	3,514
Total operating expenses	11,234	5,942	35,132	16,571
Loss from operations	(11,234)	(5,942)	(35,132)	(16,571)
Other income (expense):
Interest income, net	472	9	828	32
Other expense, net		4	(56)	1
Total other income	472	13	772	33
Net loss	$ (10,762)	$ (5,929)	$ (34,360)	$ (16,538)
Net loss per share, basic and diluted (in dollars per share)	$ (0.44)		$ (2.72)
Net loss per unit, basic and diluted (in dollars per unit)		$ (3.70)		$ (10.32)
Weighted average common shares outstanding, basic and diluted (in shares)	24,310,681		12,647,032
Weighted average common units outstanding, basic and diluted (in units)		1,603,088		1,603,088
Comprehensive loss:
Net loss	$ (10,762)	$ (5,929)	$ (34,360)	$ (16,538)
Other comprehensive income
Unrealized gain on marketable securities		13	2	14
Total other comprehensive income		13	2	14
Comprehensive loss	$ (10,762)	$ (5,916)	$ (34,358)	$ (16,524)