BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 10,575	$ 16,335
Restricted cash	269	268
Marketable securities	152,714	78,351
Interest and other receivables	1,168	436
Prepaid assets	1,332	580
Total current assets	166,058	95,970
Noncurrent marketable securities	18,582	14,241
Property and equipment, net	59	102
Other assets	585
Total assets	185,284	110,313
Current liabilities:
Accounts payable	982	503
Accrued compensation and benefits	2,642	3,385
Amount due to Janssen Biotech, Inc.	2,610	1,702
Accrued liabilities	1,317	926
Total current liabilities	7,551	6,516
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.001 par value; 3,000,000 shares authorized; no shares issued and outstanding at December 31, 2018 and 2017
Common stock, $0.001 par value; 300,000,000 shares authorized; 186,392,682 and 159,877,239 shares issued and outstanding at December 31, 2018 and 2017, respectively	186	160
Additional paid-in capital	1,189,194	1,089,684
Accumulated deficit	(1,011,464)	(985,840)
Accumulated other comprehensive loss	(183)	(207)
Total stockholders' equity	177,733	103,797
Total liabilities and stockholders' equity	$ 185,284	$ 110,313