CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 14,344,088	$ 17,988,590
Short-term investments	24,000,000	18,057,672
Receivables	109,802	175,704
Interest receivable	26,517	41,275
Prepaid expenses and other current assets	1,212,041	1,017,799
Total current assets	39,692,448	37,281,040
Equipment and furnishings, net	253,277	266,335
Goodwill	183,780	183,780
Other assets	102,271	123,268
Total assets	40,231,776	37,854,423
Current liabilities:
Accounts payable	3,060,516	2,074,463
Accrued expenses and other current liabilities	3,033,189	4,786,956
Warrant liabilities	3,972,230	6,738,934
Total current liabilities	10,065,935	13,600,353
Commitment and contingencies
Stockholders' equity (Note 2):
Preferred Stock, $.01 par value, 5,000,000 shares authorized, including 25,000 shares of Series A Junior Participating Preferred Stock; no shares issued and outstanding	0	0
Common stock, $.001 par value, 250,000,000 shares authorized; 30,607,916 and 21,302,327 shares issued and outstanding at December 31, 2012 and 2011, respectively	30,608	21,303
Additional paid-in capital	261,318,638	237,452,299
Treasury stock, at cost (90,546 shares)	(2,279,238)	(2,279,238)
Accumulated deficit	(228,904,167)	(210,940,294)
Total stockholders' equity	30,165,841	24,254,070
Total liabilities and stockholders' equity	$ 40,231,776	$ 37,854,423