Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue:
Collaboration and license revenue from related party	$ 35,952	$ 42,875	$ 82,497
Grant revenue	176	0	0
Total revenue	36,128	42,875	82,497
Operating expenses:
Research and development	70,276	62,736	49,495
General and administrative	24,155	20,409	16,509
Total operating expenses	94,431	83,145	66,004
(Loss) income from operations	(58,303)	(40,270)	16,493
Other income (expense):
Interest income	4,963	3,528	1,370
Interest expense	(2,149)	(1,224)	(4)
Total other income, net	2,814	2,304	1,366
Net (loss) income	$ (55,489)	$ (37,966)	$ 17,859
Net (loss) income per common share
Basic	$ (0.98)	$ (0.76)	$ 0.37
Diluted	$ (0.98)	$ (0.76)	$ 0.36
Shares used to compute net (loss) income per common share
Basic	56,898	49,814	48,413
Diluted	56,898	49,814	49,615