STATEMENTS OF CASH FLOWS (USD $) In Thousands	9 Months Ended		85 Months Ended
	Sep. 30, 2010	Sep. 30, 2009	Sep. 30, 2010
Cash flows from operating activities:
Net loss	$ (20,819)	$ (8,613)	$ (111,963)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	153	252	1,614
Stock-based compensation	3,198	1,264	12,103
Change in fair value of warrants	2,663	520	(3,365)
Loss on disposal of fixed assets			9
(Increase) decrease in:
Prepaid expenses and other current assets	3	(43)	(352)
Other noncurrent assets	(67)	49	(310)
Deposits	(41)		(87)
Increase (decrease) in:
Accounts payable	(703)	(1,080)	1,088
Accrued expenses	1,717	(1,228)	2,978
Deferred rent	(15)	(22)	95
Net cash used in operating activities	(13,911)	(8,901)	(98,190)
Cash flows from investing activities:
Purchases of property and equipment	(128)	(3)	(1,853)
Proceeds from sale of property and equipment			1
Net cash used in investing activities	(128)	(3)	(1,852)
Cash flows from financing activities:
Stockholders' capital contribution			500
Proceeds from exercise of stock options	225		364
Payments to employees for repurchase of common stock	(1,429)		(1,809)
Proceeds from exercise of warrants	71		349
Proceeds from issuance of common stock and warrants, net	32,804	4,605	150,349
Proceeds from issuance of preferred stock, net			16,760
Net cash provided by financing activities	31,671	4,605	166,513
Net increase (decrease) in cash and cash equivalents	17,632	(4,299)	66,471
Cash and cash equivalents, beginning of period	48,839	11,379
Cash and cash equivalents, end of period	66,471	7,080	66,471
Supplementary disclosure of cash flow information:
Cash paid for interest
Cash paid for income taxes
Supplementary disclosure of noncash investing and financing activities:
Warrants issued to placement agents and investors		4,207	47,276
Exercise of liability-classified warrants to common shares	49		49
Convertible Preferred Stock
Supplementary disclosure of noncash investing and financing activities:
Preferred stock conversion/exercise of equity-classified warrants to common stock			16,760
Warrant
Supplementary disclosure of noncash investing and financing activities:
Preferred stock conversion/exercise of equity-classified warrants to common stock	$ 239		$ 257