Sec Form 4 Filing - SIEGALL CLAY B @ Seagen Inc. - 2022-02-07

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person SIEGALL CLAY B 2. Issuer Name and Ticker or Trading Symbol Seagen Inc. [ SGEN] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) President & CEO (Last) (First) (Middle) 21823 30TH DRIVE SE 3. Date of Earliest Transaction (MM/DD/YY) 02/07/2022 (Street) BOTHELL, WA98021 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 02/07/2022 M 100 A $ 26.1 668,045( 1 ) D Common Stock 02/07/2022 S( 2 ) 100 D $ 137.29 667,945( 1 ) D Common Stock 02/07/2022 M 3,574 A $ 26.1 671,519( 1 ) D Common Stock 02/07/2022 S( 2 ) 3,574 D $ 138.97( 3 ) 667,945( 1 ) D Common Stock 02/07/2022 M 8,985 A $ 26.1 676,930( 1 ) D Common Stock 02/07/2022 S( 2 ) 8,985 D $ 139.96( 4 ) 667,945( 1 ) D Common Stock 02/07/2022 M 4,084 A $ 26.1 672,029( 1 ) D Common Stock 02/07/2022 S( 2 ) 4,084 D $ 140.83( 5 ) 667,945( 1 ) D Common Stock 02/07/2022 M 300 A $ 26.1 668,245( 1 ) D Common Stock 02/07/2022 S( 2 ) 300 D $ 141.56( 6 ) 667,945( 1 ) D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Non-Qualified Stock Option (right to buy) $ 26.1 02/07/2022 M 100 ( 7 ) 08/20/2022 Common Stock 100 $ 0 119,201 D Non-Qualified Stock Option (right to buy) $ 26.1 02/07/2022 M 3,574 ( 7 ) 08/20/2022 Common Stock 3,574 $ 0 115,627 D Non-Qualified Stock Option (right to buy) $ 26.1 02/07/2022 M 8,985 ( 7 ) 08/20/2022 Common Stock 8,985 $ 0 106,642 D Non-Qualified Stock Option (right to buy) $ 26.1 02/07/2022 M 4,084 ( 7 ) 08/20/2022 Common Stock 4,084 $ 0 102,558 D Non-Qualified Stock Option (right to buy) $ 26.1 02/07/2022 M 300 ( 7 ) 08/20/2022 Common Stock 300 $ 0 102,258 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other SIEGALL CLAY B 21823 30TH DRIVE SE BOTHELL, WA98021 X President & CEO Signatures By: /s/ Jennifer Prosba For: Clay B. Siegall 02/09/2022 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Amount of securities beneficially owned following reported transactions includes restricted stock units subject to vesting. ( 2 )The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan. ( 3 )Reflects sales of common stock executed in multiple transactions at prices ranging from $138.36 to $139.35. 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. ( 4 )Reflects sales of common stock executed in multiple transactions at prices ranging from $139.36 to $140.35. 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. ( 5 )Reflects sales of common stock executed in multiple transactions at prices ranging from $140.36 to $141.32. 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. ( 6 )Reflects sales of common stock executed in multiple transactions at prices ranging from $141.40 to $141.78. 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. ( 7 )Options vested at a rate of 25% on 8/20/13 and monthly thereafter until all the options were fully vested on 8/20/16.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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