CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 14,310	$ 44,778
Marketable securities	185,854	196,137
Receivable from related party	63	223
Notes receivable, current	200	100
Prepaid and other current assets	3,900	3,525
Total current assets	204,327	244,763
Restricted cash	893	893
Property and equipment, net	10,059	10,372
Notes receivable, non-current	140	240
Other assets, non-current	2,308	2,514
Total assets	217,727	258,782
Current liabilities:
Accounts payable	5,308	5,813
Accrued personnel related expenses	4,884	9,643
Accrued clinical and development expenses	6,547	6,956
Accrued interest on convertible subordinated notes	1,078	2,372
Other accrued liabilities	1,974	1,946
Note payable and capital lease, current	13	69
Deferred revenue, current	5,771	18,697
Total current liabilities	25,575	45,496
Convertible subordinated notes	172,500	172,500
Deferred rent	5,678	5,821
Deferred revenue, non-current	7,843	122,017
Commitments and contingencies (Notes 3 and 7)
Stockholders' equity (net capital deficiency):
Common stock, $0.01 par value; authorized: 200,000 shares; outstanding: 86,470 at March 31, 2012 and 85,543 at December 31, 2011	865	855
Additional paid-in capital	1,236,641	1,228,037
Accumulated other comprehensive income (loss)	(9)	16
Accumulated deficit	(1,231,366)	(1,315,960)
Total stockholders' equity (net capital deficiency)	6,131	(87,052)
Total liabilities and stockholders' equity (net capital deficiency)	$ 217,727	$ 258,782