Balance Sheets (Current Period Unaudited) (USD $)	Sep. 30, 2013	Dec. 31, 2012
ASSETS
Cash and cash equivalents	$ 13,170,412	$ 14,991,488
Investment securities – available for sale, at fair value	32,038,638	8,037,620
Accrued interest receivable on investment securities	251,298	65,925
Advances and deposits for investigator grants	118,240	246,252
Other current assets	519,378	307,699
Total current assets	46,097,966	23,648,984
Property and equipment (at cost, less accumulated depreciation of $1,149,961 and $924,961, respectively)	947,115	1,114,621
Deposits, deferred fees and other assets	364,173	567,188
Patent licensing fees, net	22,500	28,125
Total other assets	386,673	595,313
Total assets	47,431,754	25,358,918
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable	2,249,000	2,339,768
Accrued liabilities	1,394,120	1,254,979
Notes payable - current portion	1,944,608	1,410,455
Deferred revenue - current portion	500,000
Total current liabilities	6,087,728	5,005,202
Common stock warrant liability	5,252,660	4,283,932
Notes payable – non-current portion	2,346,973	3,661,147
Deferred revenue - non-current portion	4,125,000
Other non-current liabilities	477,919	446,779
Total liabilities	18,290,280	13,397,060
Stockholders' equity:
Common stock, $0.01 par value; 75,000,000 shares authorized; 13,740,629 and 8,437,267 shares issued at September 30, 2013 and December 31, 2012 and 13,604,975 and 8,289,507 shares outstanding at September 30, 2013 and December 31, 2012, respectively	137,406	84,373
Additional paid-in capital	197,082,448	170,957,891
Accumulated other comprehensive loss	(305,831)	(126,607)
Accumulated deficit	(165,302,674)	(156,263,288)
Subtotal	31,611,349	14,652,369
Treasury stock, at cost (135,654 and 147,760 shares at September 30, 2013 and December 31, 2012, respectively)	(2,469,875)	(2,690,511)
Total stockholders' equity	29,141,474	11,961,858
Total liabilities and stockholders' equity	$ 47,431,754	$ 25,358,918