Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Current Assets:
Cash and cash equivalents	$ 35,781	$ 78,752
Marketable securities	57,580	16,663
Prepaid expenses and other current assets	1,034	246
Total current assets	94,395	95,661
Property and Equipment, at cost:
Laboratory equipment	2,314	943
Office and computer equipment	729	188
Leasehold improvements	288	89
Furniture and fixtures	23	20
Property and Equipment, gross	3,354	1,240
Less-Accumulated depreciation and amortization	(796)	(386)
Property and Equipment, net	2,558	854
TOTAL ASSETS	96,953	96,515
Current Liabilities:
Accounts payable	765	1,028
Accrued expenses	3,069	1,987
Deferred license fees, current portion	4,143	4,143
Total current liabilities	7,977	7,158
Long term debt	1,000	1,000
Long term accrued interest	42	21
Deferred license fees, less current portion	4,439	8,582
Commitments and contingencies
Stockholders' Equity:
Preferred stock, $0.01 par value Authorized-5,000,000 shares Issued and outstanding-none at December 31, 2011 and 2010
Common stock, $0.01 par value Authorized-100,000,000 shares Issued and outstanding-56,624,763 and 52,163,629 shares at December 31, 2011 and 2010, respectively	566	522
Additional paid-in capital	304,767	272,380
Other comprehensive loss (income)	(14)	1
Accumulated deficit	(221,824)	(193,149)
Total stockholders' equity	83,495	79,754
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 96,953	$ 96,515