CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 16,823	$ 42,796
Restricted cash	266	266
Marketable securities	102,857	108,645
Interest and other receivables	1,238	963
Prepaid assets	831	736
Total current assets	122,015	153,406
Noncurrent marketable securities	31,821	18,932
Property and equipment, net	183	173
Total assets	154,019	172,511
Current liabilities:
Accounts payable	574	1,033
Accrued compensation and benefits	2,248	4,213
Accrued collaboration charges	2,498
Accrued restructuring charges	78
Accrued liabilities	727	1,537
Deferred revenue		35,000
Fair value of derivatives		16
Total current liabilities	$ 6,125	$ 41,799
Commitments and contingencies
Stockholders' equity:
Common stock	$ 158	$ 157
Additional paid-in capital	1,067,712	1,059,072
Accumulated deficit	(919,919)	(928,433)
Accumulated other comprehensive loss	(57)	(84)
Total stockholders' equity	147,894	130,712
Total liabilities and stockholders' equity	$ 154,019	$ 172,511