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 OF SECURITIES
                                                                                  
OMB APPROVAL
OMB Number: 3235-0287
Estimated average burden
hours per response...
0.5
                      
Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
                      
1. Name and Address of Reporting Person * BAKER BROS. ADVISORS LP 2. Issuer Name and Ticker or Trading Symbol Seagen Inc. [ SGEN ] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable)__X__ Director                    __X__ 10% Owner
_____ Officer (give title below)    _____ Other (specify below)
(Last)         (First)         (Middle)
860 WASHINGTON STREET, 3RD FLOOR
3. Date of Earliest Transaction (MM/DD/YYYY)
11/30/2021
(Street)
NEW YORK, NY 10014
(City)       (State)       (Zip)
4. If Amendment, Date Original Filed (MM/DD/YYYY)
 
6. Individual or Joint/Group Filing (Check Applicable Line) ___ Form filed by One Reporting Person
_ X _ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Trans. Date 2A. Deemed Execution Date, if any 3. Trans. 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  11/30/2021    S    19226  D $160  4083862  I  See Footnotes (1)(2)(3)(4)(5)
Common Stock  11/30/2021    S    208597  D $160  43100476  I  See Footnotes (2)(3)(4)(5)(6)
Common Stock  11/30/2021    S    540  D $160.0757 (7) 4083322  I  See Footnotes (1)(2)(3)(4)(5)
Common Stock  11/30/2021    S    5860  D $160.0757 (7) 43094616  I  See Footnotes (2)(3)(4)(5)(6)
Common Stock  11/30/2021    S    2713  D $160.5270 (8) 4080609  I  See Footnotes (1)(2)(3)(4)(5)
Common Stock  11/30/2021    S    29432  D $160.5270 (8) 43065184  I  See Footnotes (2)(3)(4)(5)(6)
Common Stock  11/30/2021    S    1858  D $160.9599 (9) 4078751  I  See Footnotes (1)(2)(3)(4)(5)
Common Stock  11/30/2021    S    20154  D $160.9599 (9) 43045030  I  See Footnotes (2)(3)(4)(5)(6)
Common Stock  11/30/2021    S    123  D $163.3877 (10) 4078628  I  See Footnotes (1)(2)(3)(4)(5)
Common Stock  11/30/2021    S    1337  D $163.3877 (10) 43043693  I  See Footnotes (2)(3)(4)(5)(6)
Common Stock  11/30/2021    S    886  D $164.8228 (11) 4077742  I  See Footnotes (1)(2)(3)(4)(5)
Common Stock  11/30/2021    S    9618  D $164.8228 (11) 43034075  I  See Footnotes (2)(3)(4)(5)(6)
Common Stock  11/30/2021    S    93  D $165.6841 (12) 4077649  I  See Footnotes (1)(2)(3)(4)(5)
Common Stock  11/30/2021    S    1007  D $165.6841 (12) 43033068  I  See Footnotes (2)(3)(4)(5)(6)
Common Stock  12/1/2021    S    2381  D $160.8032 (13) 4075268  I  See Footnotes (1)(2)(3)(4)(5)
Common Stock  12/1/2021    S    25833  D $160.8032 (13) 43007235  I  See Footnotes (2)(3)(4)(5)(6)
Common Stock  12/1/2021    S    768  D $161.3450  4074500  I  See Footnotes (1)(2)(3)(4)(5)
Common Stock  12/1/2021    S    8332  D $161.3450  42998903  I  See Footnotes (2)(3)(4)(5)(6)
Common Stock  12/1/2021    S    4738  D $161.3873 (14) 4069762  I  See Footnotes (1)(2)(3)(4)(5)
Common Stock  12/1/2021    S    51399  D $161.3873 (14) 42947504  I  See Footnotes (2)(3)(4)(5)(6)
Common Stock                 23280 (15) D 
 
Common Stock                 23277 (16) D 
 

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Trans. Date 3A. Deemed Execution Date, if any 4. Trans. 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 7. Title and Amount of Securities Underlying Derivative Security
(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

Explanation of Responses:
(1)  After giving effect to the transaction reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in common stock ("Common Stock") of Seagen Inc. (the "Issuer") reported in column 5 of Table I directly held by 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP),LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.
(2)  Baker Bros. Advisors LP (the "Adviser") serves as the Investment Adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held by the Funds. Baker Bros. Advisors GP LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held by the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held by the Funds.
(3)  Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds as limited partners, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the Common Stock issued upon exercise of non-qualified stock options ("Stock Options") and Common Stock received upon vesting of restricted stock units (each an "RSU") (i.e. no direct pecuniary interest).
(4)  Includes beneficial ownership of 27,500 previously issued RSUs payable solely in Common Stock issued to Felix Baker in his capacity as a director of the Issuer pursuant to the Amended and Restated 2007 Equity Incentive Plan, of which the Funds may be deemed to own a portion, and 95,000 previously issued shares from the exercise of 95,000 Stock Options of the Issuer that were issued to Felix J. Baker in his capacity as a director of the Issuer, of which the Funds may be deemed to own a portion. The policy of the Funds and the Adviser does not permit full-time employees of the Adviser or managing members of the Adviser GP to receive compensation for serving as a director of the Issuer.
(5)  Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.
(6)  After giving effect to the transaction reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I directly held by Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP ), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.
(7)  The price reported in Column 4 is a weighted average price. These shares were traded by the Funds in multiple transactions at prices ranging from $160.02 to $160.17, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission (the "Staff"), upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.
(8)  The price reported in Column 4 is a weighted average price. These shares were traded by the Funds in multiple transactions at prices ranging from $160.20 to $161.19, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.
(9)  The price reported in Column 4 is a weighted average price. These shares were traded by the Funds in multiple transactions at prices ranging from $160.23 to $161.17, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.
(10)  The price reported in Column 4 is a weighted average price. These shares were traded by the Funds in multiple transactions at prices ranging from $163.06 to $163.82, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.
(11)  The price reported in Column 4 is a weighted average price. These shares were traded by the Funds in multiple transactions at prices ranging from $164.24 to $164.99, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.
(12)  The price reported in Column 4 is a weighted average price. These shares were traded by the Funds in multiple transactions at prices ranging from $165.50 to $166.12, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.
(13)  The price reported in Column 4 is a weighted average price. These shares were traded by the Funds in multiple transactions at prices ranging from $160.60 to $160.94, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.
(14)  The price reported in Column 4 is a weighted average price. These shares were traded by the Funds in multiple transactions at prices ranging from $161.00 to $161.96, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.
(15)  Reflects Common Stock held directly by Felix J. Baker.
(16)  Reflects Common Stock held directly by Julian C. Baker.

Remarks:
Felix J. Baker, a managing member of Baker Bros. Advisors (GP) LLC, the sole general partner of Baker Bros. Advisors LP, is a director of Seagen Inc. (the "Issuer"). By virtue of their representation on the board of directors of the Issuer, for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, the reporting persons are deemed directors by deputization of the Issuer.

Reporting Owners
Reporting Owner Name / Address
Relationships
Director 10% Owner Officer Other
BAKER BROS. ADVISORS LP
860 WASHINGTON STREET, 3RD FLOOR
NEW YORK, NY 10014
X X

667, L.P.
860 WASHINGTON STREET, 3RD FLOOR
NEW YORK, NY 10014
X X

Baker Bros. Advisors (GP) LLC
860 WASHINGTON STREET, 3RD FLOOR
NEW YORK, NY 10014
X X

BAKER FELIX
860 WASHINGTON STREET, 3RD FLOOR
NEW YORK, NY 10014
X X

BAKER JULIAN
860 WASHINGTON STREET, 3RD FLOOR
NEW YORK, NY 10014
X X

Baker Brothers Life Sciences LP
860 WASHINGTON STREET, 3RD FLOOR
NEW YORK, NY 10014
X X


Signatures
Felix Baker By: /s/ Felix J. Baker 12/2/2021
**Signature of Reporting Person Date
Baker Bros. Advisors LP, Mgmt. Co. and Inv. Adviser to 667, L.P., pursuant to authority granted by Baker Biotech Capital, L.P., GP to 667, L.P. Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing 12/2/2021
**Signature of Reporting Person Date
Baker Bros. Advisors LP, Mgmt. Co. and Inv. Adviser to BAKER BROTHERS LIFE SCIENCES, L.P., pursuant to authority granted by Baker Brothers Life Sciences Capital, L.P., GP to Baker Brothers Life Sciences, L.P., Name: Scott L. Lessing, Title: President 12/2/2021
**Signature of Reporting Person Date
By: BAKER BROS. ADVISORS LP By: /s/ By: Baker Bros. Advisors LP, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing 12/2/2021
**Signature of Reporting Person Date
By: Baker Bros. Advisors (GP) LLC By: /s/ By: Baker Bros. Advisors (GP) LLC, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing 12/2/2021
**Signature of Reporting Person Date
Julian Baker By: /s/ Julian C. Baker 12/2/2021
**Signature of Reporting Person Date
Seagen (NASDAQ:SGEN)
Historical Stock Chart
From Dec 2021 to Jan 2022 Click Here for more Seagen Charts.
Seagen (NASDAQ:SGEN)
Historical Stock Chart
From Jan 2021 to Jan 2022 Click Here for more Seagen Charts.