CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 6,800	$ 10,575
Restricted cash	270	269
Marketable securities	145,180	152,714
Interest and other receivables	976	1,168
Prepaid assets	2,723	1,332
Total current assets	155,949	166,058
Noncurrent marketable securities	17,871	18,582
Property and equipment, net	89	59
Operating lease, right-of-use asset	571
Other assets	1,186	585
Total assets	175,666	185,284
Current liabilities:
Accounts payable	913	982
Accrued compensation and benefits	1,661	2,642
Amount due to Janssen Biotech, Inc.	2,071	2,610
Operating lease liability	571
Accrued liabilities	1,037	1,317
Total current liabilities	6,253	7,551
Commitments and contingencies
Stockholders' equity:
Common stock	186	186
Additional paid-in capital	1,190,651	1,189,194
Accumulated deficit	(1,021,523)	(1,011,464)
Accumulated other comprehensive gain (loss)	99	(183)
Total stockholders' equity	169,413	177,733
Total liabilities and stockholders' equity	$ 175,666	$ 185,284