Condensed Statements of Cash Flows (Unaudited) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Operating activities:
Net loss	$ (3,795)	$ (8,491)
Adjustments to reconcile net loss to net cash used in operating activities:
Change in fair value of warrants and other financial instruments	(2,179)	(2,906)
Depreciation	32	55
Amortization of license agreement	49	49
Stock-based compensation	486	474
Changes in operating assets and liabilities:
Restricted cash	35	65
Prepaid expenses and other current assets	(151)	46
Accounts payable, accrued expenses and other payables	(1,015)	(2,700)
Net cash used in operating activities	(6,538)	(13,408)
Investing activities:
Changes in other assets		38
Net cash provided by investing activities		38
Financing activities:
Proceeds from issuance of common stock, net of acquisition costs	10,396	6,652
Proceeds from exercise of employee stock plans		23
Net cash provided by financing activities	10,396	6,675
(Decrease) increase in cash and cash equivalents	3,858	(6,695)
Cash and cash equivalents at beginning of period	4,602	13,932
Cash and cash equivalents at end of period	8,460	7,237
Non- cash Disclosures:
Fair market value of stock issued in exchange for warrants	5,381
Fair market value reclassification of CEFF warrants to equity in connection with warrant exchange	3
Fair market value of private placement warrants at issuance		11,868
Fair market value reclassification of CEFF warrants to liabilities in connection with private placement		$ 103