Condensed Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Total revenue	$ 14,853	$ 7,880
Cost of sales	4,898	3,663
Gross profit	9,955	4,217
Operating expenses:
Research and development	6,480	6,389
General and administrative	3,219	2,845
Sales and marketing	1,366	858
Total operating expenses	11,065	10,092
Loss from operations	(1,110)	(5,875)
Interest expense	(211)	(230)
Other income, net	44	19
Net loss and comprehensive loss	$ (1,277)	$ (6,086)
Net loss per common share, basic and diluted	$ (0.09)	$ (0.49)
Weighted-average shares used to compute net loss per common share, basic and diluted	14,789,036	12,299,981
Product sales
Total revenue	$ 9,264	$ 6,648
Product sales - related party
Total revenue	101
Licensing, royalty and other revenue
Total revenue	5,107	91
Licensing, royalty, and other revenue - related party
Total revenue	$ 381	$ 1,141