Unaudited Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Collaboration revenue
Collaboration revenue	$ 5,175	$ 12,557	$ 45,137	$ 38,094
Expenses
Research and development	27,144	18,326	71,979	50,830
General and administrative	7,486	6,151	24,802	17,312
Depreciation and amortization	105	98	311	336
Total expenses	34,735	24,575	97,092	68,478
Other income (expense)
Investment income	1,094	198	1,787	352
Interest expense	(2,360)	(484)	(3,773)	(956)
Loss on extinguishment of debt			(1,007)
Other expenses		(3)		(3)
Total other income (expense)	(1,266)	(289)	(2,993)	(607)
Loss before taxes on income	(30,826)	(12,307)	(54,948)	(30,991)
Provision for taxes on income	9	1	15	2
Net loss	$ (30,835)	$ (12,308)	$ (54,963)	$ (30,993)
Net loss per share—basic and diluted	$ (1.07)	$ (0.50)	$ (2.03)	$ (1.34)
Weighted-average number of common shares used in net loss per share basic and diluted	28,704,853	24,845,364	27,022,269	23,196,293
License and milestone
Collaboration revenue
Collaboration revenue	$ 4,766	$ 12,501	$ 44,452	$ 37,594
Other revenue
Collaboration revenue
Collaboration revenue	$ 409	$ 56	$ 685	$ 500