CONDENSED STATEMENTS OF CASH FLOWS (Unaudited) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net loss	$ (20,267,256)	$ (21,813,157)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	89,256	87,199
Retirement of fixed assets	2,595	6,257
Stock compensation and warrant expense	1,336,667	1,309,660
Fair value adjustment on warrant liabilities	3,172,324	5,980,016
Net foreign exchange gain	(140,780)	0
Changes in assets and liabilities:
Receivables	107,351	92,805
Interest receivable	(51,443)	15,670
Prepaid expenses and other current assets	335,948	(169,486)
Accounts payable	(199,435)	506,038
Accrued expenses and other current liabilities	407,221	510,133
Net cash used in operating activities	(15,207,552)	(13,474,865)
Cash flows from investing activities:
Proceeds from sale of short-term investments	7,000,000	8,057,672
Purchases of equipment and furnishings	(22,274)	(124,960)
Net cash provided by investing activities	6,977,726	7,932,712
Cash flows from financing activities:
Repurchase of common stock for treasury	(78,975)	0
Net proceeds from exercise of stock options	933	7,200
Net cash provided by (used in) financing activities	(78,042)	7,200
Net decrease in cash and cash equivalents	(8,307,868)	(5,534,953)
Cash and cash equivalents at beginning of period	14,344,088	17,988,590
Cash and cash equivalents at end of period	6,036,220	12,453,637
Supplemental disclosure of cash flow information:
Equipment and furnishings purchased on credit	4,535	4,476
Repurchase of common stock for treasury (portion not disbursed)	15,229	0
Cash paid for income taxes	$ 34,221	$ 47,334