CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 216,840	$ 58,367
Short-term investments	165,011	201,763
Contracts receivable	3,295	5,413
Other current assets	3,575	1,302
Total current assets	388,721	266,845
Property, plant and equipment, net	1,523	77
Licenses, net	1,714	1,221
Deposits and other assets	3,047	661
Total assets	395,005	268,804
Current liabilities:
Accounts payable	2,706	2,381
Payable to Ionis Pharmaceuticals, Inc.	27,137	14,365
Accrued compensation	4,548	4,083
Accrued liabilities	25,969	7,570
Current portion of deferred revenue	35,713	58,192
Other current liabilities	1,138	1,875
Total current liabilities	97,211	88,466
Long-term portion of deferred rent	1,551	12
Long-term portion of deferred revenue	5,839	12,501
Total liabilities	104,601	100,979
Stockholders' equity:
Common stock, $0.001 par value; 125,000,000 and 100,000,000 shares authorized at June 30, 2018 and December 31, 2017, respectively; 85,680,719 and 66,541,629 shares issued and outstanding at June 30, 2018 and December 31, 2017, respectively	86	67
Additional paid-in capital	678,509	464,430
Accumulated other comprehensive loss	(297)	(451)
Accumulated deficit	(387,894)	(296,221)
Total stockholders' equity	290,404	167,825
Total liabilities and stockholders' equity	$ 395,005	$ 268,804