CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue, net	$ 5,041	$ 1,118
Cost of revenue		967
Costs and expenses:
Cost of revenue (excludes amortization)	2,777
Research and development	19,919	13,606
Sales and marketing	9,828	11,233
General and administrative	8,193	6,260
Amortization of definite-lived intangible	1,659
Total costs and expenses	42,376	32,066
Loss from operations	(37,335)	(30,948)
Other income (expense), net	(230)	719
Net loss	$ (37,565)	$ (30,229)
Net loss per share, basic and diluted	$ (0.91)	$ (0.98)
Weighted average common shares outstanding, basic and diluted (in shares)	41,248,663	30,885,928
Other comprehensive income (loss):
Unrealized gain (loss) on marketable securities, net of tax of $0	$ 34	$ (65)
Foreign currency translation adjustments	(14)	(17)
Total other comprehensive income (loss)	20	(82)
Comprehensive loss	(37,545)	(30,311)
Product sales
Revenue, net	3,778
Contract research
Revenue, net	$ 1,263	$ 1,118