Condensed Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 2,700	$ 3,405
Restricted cash	37
Prepaids and other current assets	76	25
Total current assets	2,813	3,430
Total assets	2,813	3,430
Current liabilities:
Accounts payable	69	92
Accrued expenses	176	107
Accrued payroll and related expenses	26	17
Total current liabilities	271	216
Commitments
Stockholders’ equity:
Common stock, $ 0.0001 par value; 12,000,000,000 shares authorized, 18,881,242 and 14,267,383 shares issued and outstanding at March 31, 2013 and December 31, 2012, respectively	2	1
Additional paid-in capital	443,221	439,672
Accumulated deficit	(451,569)	(447,366)
Total stockholders’ equity	2,542	3,214
Total liabilities, redeemable convertible preferred stock and stockholders' deficit	2,813	3,430
Series C-1 Convertible Preferred Stock
Stockholders’ equity:
Convertible preferred stock, value	5,780	5,792
Series C-2 Convertible Preferred Stock
Stockholders’ equity:
Convertible preferred stock, value	500	500
Series D-1 Preferred
Stockholders’ equity:
Convertible preferred stock, value	$ 4,608	$ 4,615