CONDENSED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (10,059)	$ (7,186)
Net unrealized gain (loss) on marketable securities	282	(124)
Comprehensive loss	$ (9,777)	$ (7,310)

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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