CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 161,096	$ 44,778
Short-term investments	134,393	196,137
Receivable from related party	94	223
Notes receivable, current	100	100
Prepaid and other current assets	3,398	3,525
Inventory	4,299
Total current assets	303,380	244,763
Long-term marketable securities	83,208
Restricted cash	833	893
Property and equipment, net	9,660	10,372
Notes receivable, non-current	240	240
Other assets, non-current	2,101	2,514
Total assets	399,422	258,782
Current liabilities:
Accounts payable	4,989	5,813
Accrued personnel related expenses	5,669	9,643
Accrued clinical and development expenses	4,898	6,956
Accrued interest on convertible subordinated notes	2,372	2,372
Other accrued liabilities	2,077	1,946
Note payable and capital lease, current		69
Deferred revenue, current	5,771	18,697
Total current liabilities	25,776	45,496
Convertible subordinated notes	172,500	172,500
Deferred rent	5,477	5,821
Deferred revenue, non-current	6,413	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: 96,882 at June 30, 2012 and 85,543 at December 31, 2011	969	855
Additional paid-in capital	1,456,882	1,228,037
Accumulated other comprehensive income (loss)	(109)	16
Accumulated deficit	(1,268,486)	(1,315,960)
Total stockholders' equity (net capital deficiency)	189,256	(87,052)
Total liabilities and stockholders' equity (net capital deficiency)	$ 399,422	$ 258,782