Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue:
Total revenue	$ 3,787	$ 4,799	$ 23,311	$ 13,625
Operating expenses:
Research and development	9,232	15,251	36,168	49,402
General and administrative	7,604	8,601	24,707	24,657
Restructuring and related expense	1,712	341	8,066	3,702
Loss on impairment of intangible assets		5,006		5,006
Amortization of intangible assets	146	138	418	417
Total operating expenses	18,694	29,337	69,359	83,184
Loss from operations	(14,907)	(24,538)	(46,048)	(69,559)
Interest income	164	1,366	1,497	4,334
Other income (expense), net	12	(32)	(35)	(54)
Total other income	176	1,334	1,462	4,280
Loss before income tax	(14,731)	(23,204)	(44,586)	(65,279)
Income tax benefit	191	2,252	5,856	2,322
Net loss	$ (14,540)	$ (20,952)	$ (38,730)	$ (62,957)
Net loss per common share, basic and diluted	$ (0.90)	$ (1.31)	$ (2.39)	$ (3.94)
Shares used in computing net loss per common share, basic and diluted	16,232,971	16,046,517	16,185,855	15,988,032
Collaboration and license revenue
Revenue:
Total revenue	$ 3,787	$ 4,799	$ 23,311	$ 13,625