Condensed Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Product sales (including related party sales of $572, and $734 for the three months ended March 31, 2017 and 2016)	$ 7,220	$ 6,126
Licensing and royalty revenue (including related party revenue of $569 and zero for the three months ended March 31, 2017 and 2016, respectively)	660	81
Total revenue	7,880	6,207
Cost of sales	3,663	2,545
Gross profit	4,217	3,662
Operating expenses:
Research and development	6,389	5,137
General and administrative	2,845	1,715
Sales and marketing	858	827
Total operating expenses	10,092	7,679
Loss from operations	(5,875)	(4,017)
Interest expense	(230)	(466)
Other income (expense), net	19	(57)
Net loss and comprehensive loss	$ (6,086)	$ (4,540)
Net loss per common share, basic and diluted	$ (0.49)	$ (1.78)
Weighted-average shares used to compute net loss per common share, basic and diluted	12,299,981	2,553,765