Balance Sheets (Current Period Unaudited) (USD $)	Sep. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 8,318,336	$ 20,145,854
Investment securities – available for sale, at fair value	14,229,181	10,157,160
Accrued interest receivable on investment securities	133,552	243,745
Advances and deposits for investigator grants	807,795	758,297
Vendor reimbursements receivable	173,598
Other current assets	103,728	203,429
Total current assets	23,766,190	31,508,485
Property and equipment (at cost, less accumulated depreciation of $799,712 and $643,472, respectively)	1,007,590	782,720
Other assets:
Deposits, deferred fees and other assets	605,372	322,629
Patent licensing fees, net	30,000	35,625
Total other assets	635,372	358,254
Total assets	25,409,152	32,649,459
Current liabilities:
Accounts payable	2,944,956	4,010,203
Accrued liabilities	2,715,509	2,031,934
Notes payable - current portion	945,433	110,287
Total current liabilities	6,605,898	6,152,424
Common stock warrant liability	1,417,248	166,398
Notes payable – non-current portion	4,140,186	71,602
Other non-current liabilities	221,832	65,467
Total liabilities	12,385,164	6,455,891
Stockholders' equity:
Common stock, $0.01 par value; 75,000,000 shares authorized and 35,459,494 and 33,899,057 shares issued at September 30, 2012 and December 31, 2011 and 34,792,207 and 33,186,325 shares outstanding at September 30, 2012 and December 31, 2011, respectively	354,595	338,991
Additional paid-in capital	158,121,079	153,237,225
Accumulated other comprehensive loss	(131,306)	(276,700)
Accumulated deficit	(142,620,295)	(124,221,823)
Subtotal	15,724,073	29,077,693
Treasury stock, at cost (667,287 and 712,732 shares at September 30, 2012 and December 31, 2011, respectively)	(2,700,085)	(2,884,125)
Total stockholders' equity	13,023,988	26,193,568
Total liabilities and stockholders' equity	$ 25,409,152	$ 32,649,459