Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 90,782	$ 14,848
Short-term investments	0	61,424
Certificates of deposit	2,153	0
Accounts receivable	0	757
Prepaid expenses and other current assets	643	370
Total current assets	93,578	77,399
Certificate of deposit	0	2,085
In-process research and development	58,200	58,200
Other assets	117	212
Fixed assets, net	1,666	1,937
Total assets	153,561	139,833
Current liabilities:
Accounts payable	7,060	2,334
Accrued expenses	2,933	800
Accrued compensation	2,207	795
Accrued lease expense, current	295	278
Deferred rent	149	156
Capital lease obligations, current	96	114
Current portion of long term debt	3,007	0
Total current liabilities	15,747	4,477
Accrued lease expense, long-term	647	923
Capital lease obligations, long-term	64	166
Debt, long-term	16,221	0
Total liabilities	32,679	5,566
Stockholders' equity:
Common stock; $.01 par value; 500,000,000 authorized shares,31,488,204 and 24,833,301 issued and outstanding shares at December 31, 2012 and 2011, respectively	315	248
Additional paid-in capital	455,325	427,743
Warrant to purchase 329,932 shares of common stock for $2.94 per share at December 31, 2012	790	0
Accumulated deficit	(335,548)	(294,174)
Accumulated other comprehensive income:
Unrealized gain on investments, net of taxes	0	450
Total stockholders' equity	120,882	134,267
Total liabilities and stockholders' equity	$ 153,561	$ 139,833