Consolidated Balance Sheets (USD $)	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 94,849,000	$ 44,778,000
Short-term investments	153,640,000	196,137,000
Receivables from collaboration partners (including amounts from a related party of $123 at December 31, 2012 and $223 at December 31, 2011)	1,064,000	223,000
Notes receivable, current	100,000	100,000
Prepaid and other current assets	3,966,000	3,525,000
Inventories	7,514,000
Total current assets	261,133,000	244,763,000
Long-term marketable securities	95,194,000
Restricted cash	833,000	893,000
Property and equipment, net	9,154,000	10,372,000
Notes receivable, non-current	140,000	240,000
Other assets, non-current	2,128,000	2,514,000
Total assets	368,582,000	258,782,000
Current liabilities:
Accounts payable	5,377,000	5,813,000
Accrued personnel-related expenses	9,002,000	9,643,000
Accrued clinical and development expenses	6,550,000	6,956,000
Accrued interest on convertible subordinated notes	2,372,000	2,372,000
Other accrued liabilities	2,072,000	1,946,000
Note payable and capital lease, current		69,000
Deferred revenue, current	4,593,000	18,697,000
Total current liabilities	29,966,000	45,496,000
Convertible subordinated notes	172,500,000	172,500,000
Deferred rent	5,074,000	5,821,000
Deferred revenue, non-current	6,014,000	122,017,000
Commitments and contingencies (Notes 3, 8 and 10)
Stockholders' equity (net capital deficiency):
Preferred stock, $0.01 par value, 230 shares authorized, no shares issued and outstanding
Additional paid-in capital	1,488,447,000	1,228,037,000
Accumulated other comprehensive income	99,000	16,000
Accumulated deficit	(1,334,502,000)	(1,315,960,000)
Total stockholders' equity (net capital deficiency)	155,028,000	(87,052,000)
Total liabilities and stockholders' equity (net capital deficiency)	368,582,000	258,782,000
Common stock
Stockholders' equity (net capital deficiency):
Common stock	984,000	855,000
Class A common stock
Stockholders' equity (net capital deficiency):
Common stock