Condensed Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Operating activities:
Net loss	$ (4,157)	$ (3,795)
Adjustments to reconcile net loss to net cash used in operating activities:
Change in fair value of warrants	(5)	(2,179)
Depreciation	7	32
Amortization of license agreement	49	49
Stock-based compensation	254	486
Changes in operating assets and liabilities:
Restricted cash		35
Prepaid expenses and other current assets	(281)	(151)
Accounts payable and accrued expenses	(636)	(1,015)
Net cash used in operating activities	(4,769)	(6,538)
Financing activities:
Proceeds from issuance of common stock, net of issuance costs	1,699	10,396
Net cash provided by financing activities	1,699	10,396
Increase (decrease) in cash and cash equivalents	(3,070)	3,858
Cash at beginning of period	9,972	4,602
Cash at end of period	6,902	8,460
Non-cash investing and financing activities:
Issuance of common stock in connection with the private placement warrant		5,381
Reclassification of CEFF warrants to equity from derivative liability due to exchange		$ 3