STATEMENTS OF OPERATIONS - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues:
Collaboration revenue	$ 35,000,000
License fees and royalties	1,371,000	$ 1,153,000	$ 1,283,000
Total revenues	36,371,000	1,153,000	1,283,000
Operating expenses:
Research and development	17,831,000	20,707,000	23,155,000
Restructuring charges	1,306,000		1,462,000
General and administrative	17,793,000	16,758,000	15,624,000
Total operating expenses	36,930,000	37,465,000	40,241,000
Loss from operations	(559,000)	(36,312,000)	(38,958,000)
Unrealized gain (loss) on derivatives	16,000	351,000	(316,000)
Interest and other income	677,000	373,000	951,000
Interest and other expense	(88,000)	(82,000)	(56,000)
Net income (loss)	$ 46,000	$ (35,670,000)	$ (38,379,000)
Net income (loss) per share:
Basic (in dollars per share)	$ 0.00	$ (0.23)	$ (0.30)
Diluted (in dollars per share)	$ 0.00	$ (0.23)	$ (0.30)
Shares used in computing net income (loss) per share:
Basic (in shares)	158,036,162	153,540,341	128,380,800
Diluted (in shares)	162,663,894	153,540,341	128,380,800