X0306 4/A 2020-04-15 2020-01-17 0000874015 IONIS PHARMACEUTICALS INC IONS 0001799355 Cadoret-Manier Onaiza C/O IONIS PHARMACEUTICALS, INC. 2855 GAZELLE COURT CARLSBAD CA 92010 0 1 0 0 Chief Corp Dev and Cml Officer Restricted Stock Unit 2020-04-15 2020-04-15 4 A 0 22667 0 A Common Stock 22667 22667 D Grant to reporting person of Restricted Stock Units under the Ionis Pharmaceuticals, Inc. Amended and Restated 2011 Equity Incentive Plan. Each Restricted Stock Unit represents a contingent right to receive one share of Ionis common stock, or its equivalent cash value. Restricted Stock Units vest in four equal annual installments. Upon vesting, the Restricted Stock Units will be paid out in whole shares of Ionis common stock or cash as may be determined by Ionis. The original Form 4 filed on January 17, 2020 reported Restricted Stock Units granted to the reporting person on January 15, 2020, which has been revised by this amendment to reflect the actual grant date. /s/ Patrick R. O'Neil , attorney-in-fact 2020-04-17