X0306 4 2021-07-01 0 0001060736 Seagen Inc. SGEN 0001167496 SIEGALL CLAY B 21823 30TH DRIVE SE BOTHELL WA 98021 1 1 0 0 President and CEO Common Stock 2021-07-01 4 M 0 3432 15.46 A 718641 D Common Stock 2021-07-01 4 S 0 3432 158.64 D 715209 D Common Stock 2021-07-01 4 M 0 6165 15.46 A 721374 D Common Stock 2021-07-01 4 S 0 6165 157.92 D 715209 D Common Stock 2021-07-01 4 M 0 4488 15.46 A 719697 D Common Stock 2021-07-01 4 S 0 4488 156.94 D 715209 D Common Stock 2021-07-02 4 M 0 310 15.46 A 715519 D Common Stock 2021-07-02 4 S 0 310 158.29 D 715209 D Common Stock 2021-07-02 4 M 0 2355 15.46 A 717564 D Common Stock 2021-07-02 4 S 0 2355 157.31 D 715209 D Common Stock 2021-07-02 4 M 0 7412 15.46 A 722621 D Common Stock 2021-07-02 4 S 0 7412 156.43 D 715209 D Common Stock 2021-07-02 4 M 0 5191 15.46 A 720400 D Common Stock 2021-07-02 4 S 0 5191 155.70 D 715209 D Non-Qualified Stock Option (right to buy) 15.46 2021-07-01 4 M 0 3432 0.00 D 2021-08-24 Common Stock 3432 55274 D Non-Qualified Stock Option (right to buy) 15.46 2021-07-01 4 M 0 6165 0.00 D 2021-08-24 Common Stock 6165 49109 D Non-Qualified Stock Option (right to buy) 15.46 2021-07-01 4 M 0 4488 0.00 D 2021-08-24 Common Stock 4488 44621 D Non-Qualified Stock Option (right to buy) 15.46 2021-07-02 4 M 0 310 0.00 D 2021-08-24 Common Stock 310 44311 D Non-Qualified Stock Option (right to buy) 15.46 2021-07-02 4 M 0 2355 0.00 D 2021-08-24 Common Stock 2355 41956 D Non-Qualified Stock Option (right to buy) 15.46 2021-07-02 4 M 0 7412 0.00 D 2021-08-24 Common Stock 7412 34544 D Non-Qualified Stock Option (right to buy) 15.46 2021-07-02 4 M 0 5191 0.00 D 2021-08-24 Common Stock 5191 29353 D Amount of securities beneficially owned following reported transactions includes restricted stock units subject to vesting. The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan. Reflects sales of common stock executed in multiple transactions at prices ranging from $158.30 to $159.12. The price reported reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request by the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer full information regarding the number of shares and prices at which the sales were effected. Reflects sales of common stock executed in multiple transactions at prices ranging from $157.30 to $158.28. The price reported reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request by the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer full information regarding the number of shares and prices at which the sales were effected. Reflects sales of common stock executed in multiple transactions at prices ranging from $156.30 to $157.29 The price reported reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request by the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer full information regarding the number of shares and prices at which the sales were effected. Reflects sales of common stock executed in multiple transactions at prices ranging from $158.06 to $158.41 The price reported reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request by the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer full information regarding the number of shares and prices at which the sales were effected. Reflects sales of common stock executed in multiple transactions at prices ranging from $157.03 to $157.93. The price reported reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request by the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer full information regarding the number of shares and prices at which the sales were effected. Reflects sales of common stock executed in multiple transactions at prices ranging from $156.03 to $157.02. The price reported reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request by the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer full information regarding the number of shares and prices at which the sales were effected. Reflects sales of common stock executed in multiple transactions at prices ranging from $155.02 to $156.01 The price reported reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request by the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer full information regarding the number of shares and prices at which the sales were effected. Options vested at a rate of 25% on 8/24/12 and monthly thereafter until all the options were fully vested on 8/24/15. By: /s/ Elizabeth Bekiroglu For: Clay B. Siegall 2021-07-06