Condensed Statements of Operations and Comprehensive Loss - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenue
Revenue	$ 63,142		$ 125,529
Operating expenses
Cost of revenue	16,957		51,255
Research and development expense	1,751,288	$ 691,180	3,174,331	$ 2,149,555
Sales and marketing expense	163,227		353,530
General and administrative expense	1,300,156	1,245,560	2,393,843	1,740,515
Total operating expenses	3,231,628	1,936,740	5,972,959	3,890,070
Loss from operations	(3,168,486)	(1,936,740)	(5,847,430)	(3,890,070)
Interest expense, net	(1,936,611)	(7,014)	(2,869,643)	(20,164)
Other income	15,523		18,632
Change in fair value of warrants	(173,101)		(501,617)
Net loss and comprehensive loss	(5,262,675)	(1,943,754)	(9,200,058)	(3,910,234)
Accretion of redeemable convertible preferred stock	(159,288)	(205,163)	(346,374)	(285,009)
Net loss attributable to common stockholders	$ (5,421,963)	$ (2,148,917)	$ (9,546,432)	$ (4,195,243)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (1.00)	$ (0.75)	$ (2.30)	$ (1.48)
Weighted-average common shares outstanding, basic and diluted (in shares)	5,410,661	2,874,330	4,149,502	2,833,952