Slicers (applies to each fact value in each table cell)

Reporting Entity [Axis]

0000886744 (http://www.sec.gov/CIK)

BALANCE SHEETS	Period [Axis]
	2016-12-31	2015-12-31
BALANCE SHEETS
ASSETS
Current assets:
Cash and cash equivalents	12,810,000	21,248,000
Restricted cash	268,000	267,000
Marketable securities	102,035,000	92,524,000
Interest and other receivables	475,000	1,206,000
Prepaid assets	524,000	647,000
Total current assets	116,112,000	115,892,000
Noncurrent marketable securities	13,954,000	32,661,000
Property and equipment, net	183,000	207,000
Total assets	130,249,000	148,760,000
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
Accounts payable	225,000	160,000
Accrued compensation and benefits	2,843,000	3,026,000
Accrued collaboration charges	3,367,000	2,328,000
Accrued liabilities	1,434,000	1,120,000
Total current liabilities	7,869,000	6,634,000
Commitments and contingencies	xsi:nil	xsi:nil
Stockholders' equity:
Preferred stock, $0.001 par value; 3,000,000 shares authorized; no shares issued and outstanding at December 31, 2016 and 2015	xsi:nil	xsi:nil
Common Stock, $0.001 par value; 300,000,000 shares authorized; 159,158,636 and 158,781,359 shares issued and outstanding at December 31, 2016 and 2015, respectively	159,000	159,000
Additional paid-in capital	1,080,198,000	1,070,567,000
Accumulated deficit	(957,924,000)	(928,387,000)
Accumulated other comprehensive loss	(53,000)	(213,000)
Total stockholders' equity	122,380,000	142,126,000
Total liabilities and stockholders' equity	130,249,000	148,760,000