STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities
Net loss	$ (7,226,048)	$ (3,875,229)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	7,520	5,881
Stock-based compensation expense	263,063	160,510
Noncash interest on convertible notes payable		90,498
Change in fair value of warrant liability	(1,191,514)	(91,583)
Amortization of debt issuance costs	2,700
Changes in operating assets and liabilities:
Prepaid expenses and other assets	1,331,593	(530,124)
Accounts payable and accrued expenses	191,955	738,566
Net cash used in operating activities	(6,620,731)	(3,501,481)
Cash flows from investing activities
Purchases of property and equipment		(14,029)
Net cash used in investing activities		(14,029)
Cash flows from financing activities
Proceeds from exercise of stock options	28,117	14,429
Proceeds from initial public offering, net of offering costs	41,671,360
Proceeds from notes payable, net of issuance costs	1,989,200
Proceeds from issuance of convertible preferred stock, net of issuance costs		7,531,849
Net cash provided by financing activities	43,688,677	7,546,278
Net increase in cash and cash equivalents	37,067,946	4,030,768
Cash and cash equivalents-beginning of period	10,037,123	8,633,775
Cash and cash equivalents-end of period	47,105,069	12,664,543
Supplemental disclosure of cash flow information
Conversion of preferred stock to common stock	70,340,206
Conversion of notes principal and accrued interest to preferred stock		2,761,019
Cash paid for interest	46,444
Issuance of Series C Preferred Stock	500,000
Accrued initial public offering costs	$ 469,175