CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 17,710	$ 10,575
Restricted cash	270	269
Marketable securities	134,778	152,714
Interest and other receivables	838	1,168
Prepaid and other current assets	1,166	1,332
Total current assets	154,762	166,058
Noncurrent marketable securities	9,497	18,582
Property and equipment, net	100	59
Operating lease, right-of-use asset	402
Other assets	1,464	585
Total assets	166,225	185,284
Current liabilities:
Accounts payable	1,210	982
Accrued compensation and benefits	2,756	2,642
Amount due to Janssen Biotech, Inc.	1,576	2,610
Operating lease liability	402
Accrued liabilities	3,237	1,317
Total current liabilities	9,181	7,551
Commitments and contingencies
Stockholders' equity:
Common stock	187	186
Additional paid-in capital	1,192,338	1,189,194
Accumulated deficit	(1,035,762)	(1,011,464)
Accumulated other comprehensive gain (loss)	281	(183)
Total stockholders' equity	157,044	177,733
Total liabilities and stockholders' equity	$ 166,225	$ 185,284