CONDENSED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 28,237	$ 15,267
Marketable securities-short term	9,303	15,859
Prepaid expenses and other current assets	630	822
Total current assets	38,170	31,948
Property and equipment, net	156	180
Other assets	164	252
Total assets	38,490	32,380
Current liabilities:
Accounts payable and accrued expenses	7,164	8,700
Total current liabilities	7,164	8,700
Long-term liabilities:
Notes payable	14,337
Total liabilities	21,501	8,700
Commitment and contingencies
Stockholders' equity:
Preferred stock, $0.01 par value; 1,000,000 shares authorized; no shares issued or outstanding
Common stock, $0.01 par value; 100,000,000 shares authorized; 71,146,597 and 71,146,209 shares issued and outstanding at March 31, 2017 and December 31, 2016, respectively	711	711
Additional paid-in capital	528,691	527,802
Accumulated other comprehensive income (loss)	(2)	2
Accumulated deficit	(512,411)	(504,835)
Total stockholders' equity	16,989	23,680
Total liabilities and stockholders' equity	$ 38,490	$ 32,380