Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 34,186,000	$ 40,031,000
Available-for-sale investments	19,486,000	25,232,000
Prepaid expenses and other current assets	1,234,000	1,345,000
Total current assets	54,906,000	66,608,000
Property and equipment, net	374,000	224,000
Other non-current assets	383,000	706,000
Total assets	55,663,000	67,538,000
Current liabilities:
Accounts payable	527,000	1,020,000
Accrued expenses	3,970,000	2,576,000
Other current liabilities	241,000	537,000
Total current liabilities	4,738,000	4,133,000
Total liabilities	4,738,000	4,133,000
Commitments and contingencies (Note 5)
Stockholders’ equity:
Preferred stock, $0.001 par value per share; 10,000,000 shares authorized, no shares issued and outstanding at June 30, 2016 and December 31, 2015	0	0
Common stock, $0.001 par value, 100,000,000 shares authorized at June 30, 2016 and December 31, 2015; 16,574,682 and 16,501,500 shares issued and outstanding at June 30, 2016 and December 31, 2015, respectively	16,000	16,000
Additional paid-in capital	196,607,000	194,651,000
Retained Earnings (Accumulated Deficit)	(145,708,000)	(131,251,000)
Accumulated other comprehensive income (loss)	10,000	(11,000)
Total stockholders’ equity	50,925,000	63,405,000
Total liabilities and stockholders’ equity	$ 55,663,000	$ 67,538,000