X0306 4 2019-02-13 0000874015 IONIS PHARMACEUTICALS INC IONS 0000897667 CROOKE STANLEY T C/O IONIS PHARMACEUTICALS, INC. 2855 GAZELLE COURT CARLSBAD CA 92010 1 1 0 0 Chairman and CEO Common Stock 2019-02-13 2019-02-13 4 M 0 40000 39.87 A 109634 D Common Stock 2019-02-13 2019-02-13 4 S 0 40000 60.1007 D 69634 D Common Stock 2019-02-13 2019-02-13 4 M 0 1604 10.82 A 7136 I By wife Common Stock 2019-02-13 2019-02-13 4 S 0 1604 60.00 D 5532 I By wife Common Stock 2019-02-13 2019-02-13 4 M 0 5300 39.87 A 10832 I By wife Common Stock 2019-02-13 2019-02-13 4 S 0 5300 60.00 D 5532 I By wife Common Stock 725391 I By trust Employee Stock Option (right to buy) 39.87 2019-02-13 2019-02-13 4 M 0 40000 0 D 2018-01-02 2021-01-01 Common Stock 40000 147500 D Employee Stock Option (right to buy) 10.82 2019-02-13 2019-02-13 4 M 0 1604 0 D 2017-01-02 2020-01-01 Common Stock 1604 1300 I By wife Employee Stock Option (right to buy) 39.87 2019-02-13 2019-02-13 4 M 0 5300 0 D 2018-01-02 2021-01-01 Common Stock 5300 3200 I By wife Acquired as a result of exercising a stock option pursuant to Rule 10b5-1 Trading Plan. The purchase and sale reported on this Form 4 was effective pursuant to Rule 10b5-1 Trading Plan adopted by the reporting person on 6/17/2016. Acquired as a result of exercising a stock option pursuant to Rule 10b5-1 Trading Plan. The purchase and sale reported on this Form 4 was effective pursuant to Rule 10b5-1 Trading Plan adopted by the reporting person's wife on 6/17/2016. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $60.00 to $60.30, inclusive. The reporting person undertakes to provide to Ionis Pharmaceuticals, Inc., any security holder of Ionis Pharmaceuticals, Inc. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (3) on this Form 4. /s/Patrick R. O'Neil, attorney-in-fact 2019-02-14