Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Consolidated Statements of Operations
License and collaboration revenue - related party	$ 231	$ 30,925	$ 20,063
Operating expenses:
Research and development	65,003	59,497	46,181
General and administrative	15,749	13,697	11,779
Total operating expenses	80,752	73,194	57,960
Loss from operations	(80,521)	(42,269)	(37,897)
Interest income	2,813	2,566	948
Interest expense	(169)
Other expense, net	(1)	(20)	(8)
Loss before income tax benefit	(77,878)	(39,723)	(36,957)
Income tax benefit	691	799
Net loss	$ (77,187)	$ (38,924)	$ (36,957)
Net loss per share, basic and diluted	$ (2.98)	$ (1.74)	$ (2.09)
Weighted-average shares used to compute net loss per share, basic and diluted	25,894,024	22,364,515	17,694,505