CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 135,744	$ 306,866
Short-term investments	254,144	156,806
Accounts receivable	14,049	10,496
Receivable from Ionis Pharmaceuticals, Inc.		3,231
Inventories	13,756	8,817
Other current assets	10,480	10,689
Total current assets	428,173	496,905
Property, plant and equipment, net	5,895	5,261
Operating lease right-of-use assets	10,646	11,094
Intangible assets, net	80,127	83,051
Deposits and other assets	3,096	2,939
Total assets	527,937	599,250
Current liabilities:
Accounts payable	4,253	10,216
Payable to Ionis Pharmaceuticals, Inc.	5,320
Accrued compensation	8,313	12,793
Accrued liabilities	12,316	14,191
Deferred revenue	263	2,165
Other current liabilities	4,716	2,633
Total current liabilities	35,181	41,998
Long-term portion of lease liabilities	13,545	14,248
Other long-term liabilities	183
Total liabilities	48,909	56,246
Stockholders’ equity:
Common stock, $0.001 par value; 125,000,000 shares authorized at June 30, 2020 and December 31, 2019; 101,509,223 and 100,993,173 shares issued and outstanding at June 30, 2020 and December 31, 2019, respectively.	102	101
Additional paid-in capital	1,051,142	1,024,168
Accumulated other comprehensive income	1,481	5
Accumulated deficit	(573,697)	(481,270)
Total stockholders’ equity	479,028	543,004
Total liabilities and stockholders’ equity	$ 527,937	$ 599,250