Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Operating activities:
Net loss	$ (11,637)	$ (21,863)
Adjustments to reconcile net loss to net cash used in operating activities:
Compensation related to restricted stock, stock options and employee stock purchase plan	688	1,644
Depreciation and amortization	1,005	1,203
Non-cash research and development expense	30	3,790
Non-cash amortization of discount on notes payable and debt issuance costs	0	1,578
Non-cash restructuring expense	1,298	678
Accretion of restructuring liability	92	87
Net gain on settlement of liabilities	0	(29)
Change in fair value of price adjustable warrants and subscription investment units	(4,704)	(2,691)
Changes in assets and liabilities:
Accounts receivable	49	50
Prepaid expenses and other assets	372	311
Accounts payable	(1,012)	810
Deferred revenue	480	0
Accrued expenses and deferred rent and other liabilities	(488)	855
Accrued restructuring	(368)	(395)
Net cash used in operating activities	(14,195)	(13,972)
Investing activities:
Change in restricted cash	(140)	(159)
Purchases of property and equipment	0	(381)
Cash acquired upon acquisition of Cequent Pharmaceuticals	0	5,063
Net cash provided by (used in) investing activities	(140)	4,523
Financing activities:
Proceeds from sales of common shares and warrants, net	10,726	4,943
Proceeds from exercise of warrants, subscription investment units, stock options and employee stock purchase plan purchases	3,587	2,705
Borrowings on note payable	0	3,000
Payments on notes payable	0	(1,000)
Net cash provided by financing activities	14,313	9,648
Net increase (decrease) in cash	(22)	199
Cash - beginning of year	1,066	748
Cash - end of period	1,044	947
Non-cash financing activities:
Issuance of stock to acquire Cequent Pharmaceuticals and termination of notes payable, accrued interest and warrants issued to Cequent	0	30,337
Issuance of common stock to settle liabilities	1,562	126
Supplemental disclosure:
Cash paid for interest	$ 0	$ 10