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
Operating expenses:
Research and development	$ 16,553	$ 11,845	$ 25,405	$ 19,951
General and administrative	2,616	2,268	5,455	4,362
Total operating expenses	19,169	14,113	30,860	24,313
Loss from operations	(19,169)	(14,113)	(30,860)	(24,313)
Other income, net	847	522	1,478	863
Loss before income taxes	(18,322)	(13,591)	(29,382)	(23,450)
Income tax expense	10		19
Net loss	$ (18,332)	$ (13,591)	$ (29,401)	$ (23,450)
Net loss per share, basic and diluted	$ (0.51)	$ (0.48)	$ (0.91)	$ (0.95)
Weighted-average common shares used in computing net loss per share, basic and diluted	35,684,368	28,046,315	32,248,646	24,802,713
Other comprehensive gain (loss):
Net loss	$ (18,332)	$ (13,591)	$ (29,401)	$ (23,450)
Unrealized gain (loss) on marketable securities	138	(30)	211	(30)
Comprehensive loss	$ (18,194)	$ (13,621)	$ (29,190)	$ (23,480)

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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