Condensed Consolidated Statements of Operations - USD ($) shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Total revenue	$ 195,000	$ 167,000	$ 336,000	$ 353,000
Operating expenses:
Research and development	17,271,000	9,583,000	32,519,000	22,879,000
General and administrative	9,656,000	9,081,000	19,397,000	18,986,000
Restructuring credits	0	0	0	(61,000)
Total operating expenses	26,927,000	18,664,000	51,916,000	41,804,000
Loss from operations	(26,732,000)	(18,497,000)	(51,580,000)	(41,451,000)
Other income (expense):
Interest income	179,000	2,296,000	1,316,000	4,600,000
Other income (expense), net	16,000	235,000	(8,000)	218,000
Total other income, net	195,000	2,531,000	1,308,000	4,818,000
Loss before income taxes	(26,537,000)	(15,966,000)	(50,272,000)	(36,633,000)
Provision for (benefit from) income taxes	(255,000)	(156,000)	(421,000)	42,000
Net loss	$ (26,282,000)	$ (15,810,000)	$ (49,851,000)	$ (36,675,000)
Basic and diluted net loss per share (in dollars per share)	$ (0.66)	$ (0.40)	$ (1.25)	$ (0.92)
Shares used to compute basic and diluted net loss per share (in shares)	39,911	39,872	39,910	39,868
Collaboration
Total revenue	$ 145,000	$ 167,000	$ 286,000	$ 353,000
License
Total revenue	$ 50,000	$ 0	$ 50,000	$ 0