CONDENSED BALANCE SHEETS (Unaudited) (USD $)	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Current assets:
Cash and cash equivalents	$ 11,429,671	$ 14,344,088	$ 16,916,696
Short-term investments	21,000,000	24,000,000
Receivables	10,294	109,802
Interest receivable	40,168	26,517
Investment in Mast Therapeutics, at market	62,945	0
Prepaid expenses and other current assets	1,462,098	1,212,041
Total current assets	34,005,176	39,692,448
Equipment and furnishings, net	226,975	253,277
Goodwill	183,780	183,780
Other assets	102,271	102,271
Total assets	34,518,202	40,231,776
Current liabilities:
Accounts payable	1,851,300	3,060,516
Accrued expenses and other current liabilities	2,989,712	3,033,189
Warrant liabilities	6,067,450	3,972,230
Total current liabilities	10,908,462	10,065,935
Commitments and contingencies
Stockholders' equity
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 shares issued and outstanding at March 31, 2013 and December 31, 2012)	30,608	30,608
Additional paid-in capital	261,626,646	261,318,638
Treasury stock, at cost (90,546 shares)	(2,279,238)	(2,279,238)
Accumulated deficit	(235,768,276)	(228,904,167)
Total stockholders' equity	23,609,740	30,165,841
Total liabilities and stockholders' equity	$ 34,518,202	$ 40,231,776