CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS
Revenues	$ 2,721	$ 2,632	$ 7,856	$ 8,140
Cost of revenues	1,750	1,471	4,672	4,941
Gross profit	971	1,161	3,184	3,199
Operating expenses:
Research and development	3,955	2,731	11,766	8,350
Selling, general and administrative	6,892	4,575	19,802	12,900
Total operating expenses	10,847	7,306	31,568	21,250
Loss from operations	(9,876)	(6,145)	(28,384)	(18,051)
Interest income	11		23	1
Interest expense	(1,334)	(1,712)	(4,002)	(4,905)
Other income (expense), net	(2,058)	(920)	(1,525)	(837)
Loss before provision for income taxes	(13,257)	(8,777)	(33,888)	(23,792)
Provision for income taxes	(7)	3		37
Net loss and comprehensive loss	(13,250)	(8,780)	(33,888)	(23,829)
Adjustment to net loss resulting from convertible preferred stock modification			(2,384)
Net loss and comprehensive loss attributable to common stockholders	$ (13,250)	$ (8,780)	$ (36,272)	$ (23,829)
Net loss per share, basic and diluted (in dollars per share)	$ (1.08)	$ (36.43)	$ (3.32)	$ (98.88)
Weighted average common shares used to compute net loss per share, basic and diluted	12,280	241	10,935	241