Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenue:
Product revenue	$ 475	$ 416
Collaboration revenue		42
Total revenue	475	458
Costs and operating expenses:
Cost of product revenue	115	99
Research and development	6,729	7,073
Selling and marketing	6,027	1,389
General and administrative	3,276	2,406
Total costs and operating expenses	16,147	10,967
Loss from operations	(15,672)	(10,509)
Other income (expense):
Interest income	92	87
Interest expense	(443)	(418)
Total other expense, net	(351)	(331)
Net loss	$ (16,023)	$ (10,840)
Net loss per share, basic and diluted	$ (0.58)	$ (0.44)
Weighted average common shares outstanding, basic and diluted	27,643,746	24,751,682
Comprehensive loss:
Net loss	$ (16,023)	$ (10,840)
Other comprehensive income (loss):
Unrealized gain (loss) on marketable securities	(4)	68
Total other comprehensive income (loss)	(4)	68
Total comprehensive loss	$ (16,027)	$ (10,772)