CONDENSED STATEMENTS OF CASH FLOWS (Unaudited) (USD $)	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:
Net loss	$ (11,054,955)	$ (10,287,251)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	64,856	59,226
Stock compensation and warrant expense	2,627,010	762,748
Fair value adjustment on warrant liabilities	(12,234,301)	(838,487)
Net foreign exchange gain	(64)	(138,709)
Changes in assets and liabilities:
Receivables	(1,480,067)	(101,824)
Interest receivable	(48,929)	(29,934)
Prepaid expenses and other current assets	1,410,893	631,137
Accounts payable	(160,032)	(278,151)
Accrued expenses and other current liabilities	3,832,235	(139,290)
Net cash used in operating activities	(17,043,354)	(10,360,535)
Cash flows from investing activities:
Purchase of short-term investments	(45,601,506)	0
Proceeds from the sale of short-term investments	22,084,980	7,000,000
Purchases of equipment and furnishings	(20,733)	(4,000)
Net cash provided by (used in) investing activities	(23,537,259)	6,996,000
Cash flows from financing activities:
Net proceeds from public offering	80,535,401	0
Proceeds from issuance of restricted stock to employee	100	0
Net proceeds from exercise of warrants and stock options	428,891	933
Net cash provided by financing activities	80,964,392	933
Net increase (decrease) in cash and cash equivalents	40,383,779	(3,363,602)
Cash and cash equivalents at beginning of period	11,483,112	14,344,088
Cash and cash equivalents at end of period	51,866,891	10,980,486
Supplemental disclosure of cash flow information:
Equipment and furnishings purchased on credit	107,506	1,529
Cashless warrant exercises	133	0
Repurchase of stock for treasury	115,954	56,580
Cash paid for income taxes	$ 59,431	$ 5,600