Condensed Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 13,405	$ 18,653
Marketable securities	0	4,000
Prepaid expenses and other current assets	1,229	2,463
Total current assets	14,634	25,116
Property and equipment, net	123	139
Other assets	45	45
Total assets	14,802	25,300
Current liabilities:
Accounts payable	1,437	550
Accrued expenses and other current liabilities	16,626	8,740
Current portion of note payable, net of discount	8,923	7,800
Total current liabilities	26,986	17,090
Note payable, net of current portion and discount	10,026	13,005
Warrant liability	385	830
Other liabilities	15,388	24,387
Commitments and contingencies
Stockholders' deficit:
Common stock, $.0001 par value; 100,000,000 shares authorized, 867,204 shares issued and outstanding at March 31, 2013 and December 31, 2012	0	0
Additional paid-in-capital	0	0
Accumulated deficit	(212,214)	(200,661)
Total stockholders' deficit	(212,214)	(200,661)
Total liabilities, convertible preferred stock and stockholders' deficit	14,802	25,300
Series A-1 Convertible Preferred Stock
Current liabilities:
Preferred Stock	73,587	71,957
Stockholders' deficit:
Total stockholders' deficit	73,587	71,957
Series A-2 Convertible Preferred Stock
Current liabilities:
Preferred Stock	88,420	86,714
Stockholders' deficit:
Total stockholders' deficit	88,420	86,714
Series A-3 Convertible Preferred Stock
Current liabilities:
Preferred Stock	11,428	11,182
Stockholders' deficit:
Total stockholders' deficit	11,428	11,182
Series A-4 Convertible Preferred Stock
Current liabilities:
Preferred Stock	271	271
Stockholders' deficit:
Total stockholders' deficit	271	271
Series A-5 Convertible Preferred Stock
Current liabilities:
Preferred Stock	525	525
Stockholders' deficit:
Total stockholders' deficit	525	525
Series A-6 Convertible Preferred Stock
Current liabilities:
Preferred Stock	0	0
Stockholders' deficit:
Total stockholders' deficit	$ 0