Condensed Statements of Cash Flows (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Operating activities
Net loss	$ (3,520,748)	$ (2,955,484)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	371,600	223,310
Non-cash interest	15,174	5,816
Deferred rent expense	(3,298)	8,688
Change in operating assets and liabilities:
Prepaid expenses and other assets	73,333	58,015
Accounts payable and accrued expenses	68,870	659,038
Net cash used in operating activities	(2,995,069)	(2,000,617)
Financing activities
Payments on bank line of credit		(360,576)
Proceeds from issuance of common stock, net	531,620
Net cash provided by (used in) financing activities	531,620	(360,576)
Net decrease in cash and cash equivalents	(2,463,449)	(2,361,193)
Cash and cash equivalents at beginning of period	14,155,809	24,196,691
Cash and cash equivalents at end of period	11,692,360	21,835,498
Supplemental disclosure of cash flow information
Interest paid	$ 41,250	$ 32,495