SGEN / Seagen Inc - Документы SEC, Годовой отчет, Доверенное заявление

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number: 0-32405 SEAGEN INC. (Exact name of registrant as specified in its charter) 2

SGEN / Seagen Inc / BAKER BROS. ADVISORS LP - SC 13D/A Activist Investment

SC 13D/A 1 tm2333184d1sc13da.htm SC 13D/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 35) Seagen Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 81181C104 (CUSIP Number) Alexandra A. Toohey Chief Financial Officer Baker Bros. Advisors LP 860 Washington Str

As filed with the Securities and Exchange Commission on December 14, 2023

S-8 POS As filed with the Securities and Exchange Commission on December 14, 2023 Registration No.

As filed with the Securities and Exchange Commission on December 14, 2023

POSASR As filed with the Securities and Exchange Commission on December 14, 2023 Registration No.

AMENDED AND RESTATED CERTIFICATE OF INCORPORATION SEAGEN INC. ARTICLE I

Exhibit 3.1 AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF SEAGEN INC. ARTICLE I The name of the corporation is: Seagen Inc. (the “Corporation”). ARTICLE II The address, including street, number, city, and county of the registered office of the Corporation in the State of Delaware is the Corporation Trust Center, 1209 Orange Street, City of Wilmington, County of New Castle, State of Delaware

As filed with the Securities and Exchange Commission on December 14, 2023

S-8 POS As filed with the Securities and Exchange Commission on December 14, 2023 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 14, 2023 Seagen Inc. (Ex

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 14, 2023 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commis

BY-LAWS SEAGEN INC. dated as of DECEMBER 14, 2023

Exhibit 3.2 BY-LAWS of SEAGEN INC. dated as of DECEMBER 14, 2023 TABLE OF CONTENTS Page ARTICLE I OFFICES 1 SECTION 1. REGISTERED OFFICE 1 SECTION 2. OTHER OFFICES 1 ARTICLE II MEETINGS OF STOCKHOLDERS 1 SECTION 1. ANNUAL MEETINGS 1 SECTION 2. SPECIAL MEETINGS 1 SECTION 3. VOTING 1 SECTION 4. QUORUM 2 SECTION 5. NOTICE OF MEETINGS 2 SECTION 6. ACTION WITHOUT MEETING 2 ARTICLE III DIRECTORS 2 SECTI

As filed with the Securities and Exchange Commission on December 14, 2023

S-8 POS As filed with the Securities and Exchange Commission on December 14, 2023 Registration No.

As filed with the Securities and Exchange Commission on December 14, 2023

S-8 POS As filed with the Securities and Exchange Commission on December 14, 2023 Registration No.

As filed with the Securities and Exchange Commission on December 14, 2023

S-8 POS As filed with the Securities and Exchange Commission on December 14, 2023 Registration No.

As filed with the Securities and Exchange Commission on December 14, 2023

S-8 POS As filed with the Securities and Exchange Commission on December 14, 2023 Registration No.

EX-99.25

Form 25

As filed with the Securities and Exchange Commission on December 14, 2023

As filed with the Securities and Exchange Commission on December 14, 2023 Registration No.

As filed with the Securities and Exchange Commission on December 14, 2023

S-8 POS As filed with the Securities and Exchange Commission on December 14, 2023 Registration No.

As filed with the Securities and Exchange Commission on December 14, 2023

As filed with the Securities and Exchange Commission on December 14, 2023 Registration No.

As filed with the Securities and Exchange Commission on December 14, 2023

As filed with the Securities and Exchange Commission on December 14, 2023 Registration No.

As filed with the Securities and Exchange Commission on December 14, 2023

As filed with the Securities and Exchange Commission on December 14, 2023 Registration No.

As filed with the Securities and Exchange Commission on December 14, 2023

S-8 POS As filed with the Securities and Exchange Commission on December 14, 2023 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of report (Date of earliest event reported): December 12, 2023 SEAGEN INC. (Ex

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of report (Date of earliest event reported): December 12, 2023 SEAGEN INC. (Exact name of registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation) (Commission File Number

DocuSign Envelope ID: 957D7C6A-474D-4395-B955-ABE3102635BC

DocuSign Envelope ID: 957D7C6A-474D-4395-B955-ABE3102635BC POWER OF ATTORNEY The undersigned hereby constitutes and appoints Jean Liu, Todd Simpson, Jessica Nielsen Causey and Jennifer Prosba, each of them, his or her true and lawful attorney-in-fact to: (1) execute for and on behalf of the undersigned, in the undersigned’s capacity as an affiliate of Seagen Inc.

Form of Global Stock Unit Grant Notice and Global Stock Unit Agreement under the Amended and Restated 2007 Equity Incentive Plan (approved

SEAGEN INC. GLOBAL STOCK UNIT GRANT NOTICE (AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN) Seagen Inc. (the “Company”), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the “Plan”), hereby awards to Participant a Stock Unit Award for the number of stock units set forth below (the “Award”). The Award is subject to all of the terms and conditions as set forth herein and in the Plan

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file numbe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 1, 2023 SEAGEN INC. (Exa

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 1, 2023 SEAGEN INC. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commiss

Seagen Third Quarter 2023 Financial Results Reflect Strong Product Sales Growth, and Significant Portfolio and Pipeline Progress -Record Net Product Sales of $571 Million in 3Q23, a 33% Increase Over 3Q22, Primarily Driven by PADCEV® First-Line Launc

Exhibit 99.1 Seagen Third Quarter 2023 Financial Results Reflect Strong Product Sales Growth, and Significant Portfolio and Pipeline Progress -Record Net Product Sales of $571 Million in 3Q23, a 33% Increase Over 3Q22, Primarily Driven by PADCEV® First-Line Launch- -PADCEV with Keytruda® Potentially Practice Changing for First-Line Metastatic Urothelial Cancer after EV-302 Trial Demonstrates Near

Stock Unit Agreement under the Amended and Restated 2007 Equity Incentive Plan (approved

SEAGEN INC. GLOBAL PERFORMANCE STOCK UNIT GRANT NOTICE (AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN) Seagen Inc. (the “Company”), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the “Plan”), hereby awards to Participant a Stock Unit Award for the number of stock units set forth below (the “Award”). The Award is subject to all of the terms and conditions as set forth herein and

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 19, 2023 Seagen Inc. (Exa

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 19, 2023 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commiss

PADCEV® (enfortumab vedotin-ejfv) and KEYTRUDA® (pembrolizumab) Significantly Improve Overall Survival and Progression-Free Survival in Patients With Previously Untreated Advanced Bladder Cancer in Pivotal Phase 3 EV-302 Trial – Trial results to be s

EX-99.1 Exhibit 99.1 PADCEV® (enfortumab vedotin-ejfv) and KEYTRUDA® (pembrolizumab) Significantly Improve Overall Survival and Progression-Free Survival in Patients With Previously Untreated Advanced Bladder Cancer in Pivotal Phase 3 EV-302 Trial – Trial results to be submitted for presentation at upcoming medical meeting – BOTHELL, Wash. and TOKYO – September 22, 2023 — Seagen Inc. (Nasdaq: SGEN

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 22, 2023 Seagen Inc. (E

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 22, 2023 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commi

Seagen and Genmab Announce TIVDAK® (tisotumab vedotin-tftv) Improved Overall Survival in Patients With Recurrent or Metastatic Cervical Cancer Compared With Chemotherapy Alone

EX-99.1 Exhibit 99.1 Seagen and Genmab Announce TIVDAK® (tisotumab vedotin-tftv) Improved Overall Survival in Patients With Recurrent or Metastatic Cervical Cancer Compared With Chemotherapy Alone BOTHELL, Wash., and COPENHAGEN, Denmark, September 4, 2023 — Seagen Inc. (Nasdaq: SGEN) and Genmab A/S (Nasdaq: GMAB) announced today that the Phase 3 innovaTV 301 global trial in recurrent or metastatic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 4, 2023 Seagen Inc. (Ex

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 4, 2023 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commis

POWER OF ATTORNEY

Exhibit 24 POWER OF ATTORNEY The undersigned hereby constitutes and appoints Jean Liu, Todd Simpson, Jessica Nielsen Causey and Jennifer Prosba, each of them, his or her true and lawful attorney-in-fact to: (1) execute for and on behalf of the undersigned, in the undersigned’s capacity as an affiliate of Seagen Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 16, 2023 Seagen Inc. (Exac

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 16, 2023 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commissi

POWER OF ATTORNEY

Exhibit 24 POWER OF ATTORNEY The undersigned hereby constitutes and appoints Todd Simpson, Jessica Nielsen Causey and Jennifer Prosba, each of them, his or her true and lawful attorney-in-fact to: (1) execute for and on behalf of the undersigned, in the undersigned’s capacity as an affiliate of Seagen Inc.

POWER OF ATTORNEY

Exhibit 24 POWER OF ATTORNEY The undersigned hereby constitutes and appoints Jean Liu, Jessica Nielsen Causey and Jennifer Prosba, each of them, his or her true and lawful attorney-in-fact to: (1) execute for and on behalf of the undersigned, in the undersigned’s capacity as an affiliate of Seagen Inc.

POWER OF ATTORNEY

Exhibit 24 POWER OF ATTORNEY The undersigned hereby constitutes and appoints Jean Liu, Todd Simpson, Jessica Nielsen Causey and Jennifer Prosba, each of them, his or her true and lawful attorney-in-fact to: (1) execute for and on behalf of the undersigned, in the undersigned’s capacity as an affiliate of Seagen Inc.

Seagen Phase 3 Trial of TUKYSA® (tucatinib) in Combination with Antibody-Drug Conjugate ado-trastuzumab emtansine Meets Primary Endpoint of Progression-Free Survival in Patients with Previously Treated HER2-Positive Metastatic Breast Cancer

Exhibit 99.1 Seagen Phase 3 Trial of TUKYSA® (tucatinib) in Combination with Antibody-Drug Conjugate ado-trastuzumab emtansine Meets Primary Endpoint of Progression-Free Survival in Patients with Previously Treated HER2-Positive Metastatic Breast Cancer BOTHELL, Wash.—August 16, 2023—Seagen Inc. (Nasdaq: SGEN) today announced that the Phase 3 HER2CLIMB-02 clinical trial of TUKYSA® (tucatinib) in c

Fifteenth Amendment to Development and Supply Agreement, effective May 23, 2023 between Seagen Inc. and AbbVie Inc. (formerly part of Abbott Laboratories).

ex102-abbviedevelopmenta [*] = Certain confidential information contained in this document, marked by brackets, has been omitted because it is both (i) not material and (ii) the type that the registrant treats as private or confidential.

Calculation of Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-8 (Form Type) Seagen Inc. (Exact name of registrant as specified in its charter) Security Type Security Class Title Fee Calculation Rule Amount Registered(1) Proposed Maximum Offering Price Per Unit(2) Maximum Aggregate Offering Price(2) Fee Rate Amount of Registration Fee Equity Common Stock, $0.001 par value per share, reserved for issuance und

As filed with the Securities and Exchange Commission on August 2, 2023

S-8 As filed with the Securities and Exchange Commission on August 2, 2023 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 2, 2023 SEAGEN INC. (Exact

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 2, 2023 SEAGEN INC. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commissio

Fourteenth Amendment to Development and Supply Agreement, effective May 10, 2023 between Seagen Inc. and AbbVie Inc. (formerly part of Abbott Laboratories).

ex101-abbviedevelopmenta [*] = Certain confidential information contained in this document, marked by brackets, has been omitted because it is both (i) not material and (ii) the type that the registrant treats as private or confidential.

Seagen Second Quarter 2023 Financial Results Demonstrate Exceptional Commercial Performance Driving Record Product Sales with Strong Growth and Momentum -Record Net Product Sales of $544 Million in 2Q23, an Increase of 26% Over 2Q22, Contributing to

Exhibit 99.1 Seagen Second Quarter 2023 Financial Results Demonstrate Exceptional Commercial Performance Driving Record Product Sales with Strong Growth and Momentum -Record Net Product Sales of $544 Million in 2Q23, an Increase of 26% Over 2Q22, Contributing to Total Revenues of $604 Million in 2Q23- -Strong PADCEV® Growth Driven By Combination First-Line Advanced Urothelial Cancer Launch; Record

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 0-3

Amended and Restated 2007 Equity Incentive Plan, effective as of May 31, 2023.

ex104-seagenxar2007equit Exhibit 10.4 SEAGEN INC. AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN (amended and restated by the Board August 5, 2009) (amended and restated by the Board March 11, 2010) (approved by the Company’s stockholders May 21, 2010) (amended and restated by the Board February 16, 2012) (approved by the Company’s stockholders May 18, 2012) (amended and restated by the Board Feb

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 14, 2023 Seagen Inc. (Exact

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 14, 2023 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 14, 2023 Seagen Inc. (Exact

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 14, 2023 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

SGEN / Seagen Inc / Capital International Investors - SEC SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 8 )* Seagen Inc. (Name of Issuer) Common Stock (Title of Class of Securities) 81181C104 (CUSIP Number) May 31, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is fil

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 31, 2023 Seagen Inc. (Exact n

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 31, 2023 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

Seagen Stockholders Approve Acquisition by Pfizer

EX-99.1 Exhibit 99.1 Seagen Stockholders Approve Acquisition by Pfizer 05/30/23 BOTHELL, Wash.—(BUSINESS WIRE)—Following a special meeting of its stockholders, Seagen Inc. (Nasdaq: SGEN) today announced that its stockholders voted to approve a proposal to adopt the previously announced merger agreement under which Pfizer will acquire Seagen for $229 per share in cash. More than 99% of the shares v

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 30, 2023 Seagen Inc. (Exact n

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 30, 2023 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 23, 2023 Seagen Inc. (Exact n

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 23, 2023 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule

POWER OF ATTORNEY

POWER OF ATTORNEY The undersigned hereby constitutes and appoints Jean Liu, Todd Simpson, Jessica Nielsen Causey and Jennifer Prosba, each of them, his or her true and lawful attorney-in-fact to: (1) execute for and on behalf of the undersigned, in the undersigned’s capacity as an affiliate of Seagen Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 15, 2023 Seagen Inc. (Exact n

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 15, 2023 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

SGEN / Seagen Inc / BAKER BROS. ADVISORS LP - SC 13D/A Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 34) Seagen Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 81181C104 (CUSIP Number) Alexandra A. Toohey Chief Financial Officer Baker Bros. Advisors LP 860 Washington Street, 3rd Floor New York, NY 10014 (212) 33

PROCEEDS AGREEMENT

Exhibit 99.2 PROCEEDS AGREEMENT AGREEMENT dated as of May 1, 2023 by and between Baker Bros. Advisors LP (the “Management Company”) and Felix Baker (the “Agent”). WHEREAS, the Agent, in his capacity as a director of Seagen Inc. (the “Company”), received non-transferable options (the “Options”) to purchase 8,750 shares of the Company common stock (the “Stock”) according to the below Schedule A; WHE

Loan Agreement Between Baker Brothers Life Sciences, L.P., 667, L.P., and Baker Bros. Advisors LP

Exhibit 99.1 Loan Agreement Between Baker Brothers Life Sciences, L.P., 667, L.P., and Baker Bros. Advisors LP For value received, Baker Bros. Advisors LP (the “Management Company”) promises to pay Baker Brothers Life Sciences, L.P., and 667, L.P., (collectively “The Funds”), the amounts set forth in Schedule A below, payable on the Due Date (as defined below) with interest payable through the Due

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule

Amendment No. 2 to Commercial Supply Agreement dated January 17, 2023 between Seagen Inc. and Esteve Quimica, S.A.

ex107estevecommercialsup [*] = Certain confidential information contained in this document, marked by brackets, has been omitted because it is both (i) not material and (ii) the type that the registrant treats as private or confidential.

Letter Agreement dated December 7, 2021 between Seagen Inc. and RemeGen Co., Ltd.

ex105remegen-sideletterx [*] = Certain confidential information contained in this document, marked by brackets, has been omitted because it is both (i) not material and (ii) the type that the registrant treats as private or confidential.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 0-

Seagen Reports First Quarter 2023 Financial Results -Total Revenues of $520 Million in 1Q23, Including Net Product Sales of $469 Million- -PADCEV® Granted FDA Accelerated Approval in Combination with KEYTRUDA® as First-Line Treatment for Cisplatin-In

Exhibit 99.1 Seagen Reports First Quarter 2023 Financial Results -Total Revenues of $520 Million in 1Q23, Including Net Product Sales of $469 Million- -PADCEV® Granted FDA Accelerated Approval in Combination with KEYTRUDA® as First-Line Treatment for Cisplatin-Ineligible Patients with Locally Advanced or Metastatic Urothelial Cancer- -Presented Data at AACR on Multiple Targeted Cancer Pipeline Ass

Second Amendment to Lease dated July 1, 2008 between Seagen Inc. and B&N 141-302, LLC.

ex104bnsecondamendmentt [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL.

Form of Global Stock Unit Grant Notice and Global Stock Unit Agreement under the Amended and Restated 2007 Equity Incentive Plan (approved March 30, 2023).

ex109-for10xqfilingxform EXHIBIT 10.9 SEAGEN INC. GLOBAL STOCK UNIT GRANT NOTICE (AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN) Seagen Inc. (the “Company”), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the “Plan”), hereby awards to Participant a Stock Unit Award for the number of stock units set forth below (the “Award”). The Award is subject to all of the terms and conditio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 27, 2023 SEAGEN INC. (Exact

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 27, 2023 SEAGEN INC. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commissio

Letter Agreement dated March 9, 2023 between Seagen Inc. and RemeGen Co., Ltd.

ex106remegen-seagenxside CONFIDENTIAL Page 1 of 3 [*] = Certain confidential information contained in this document, marked by brackets, has been omitted because it is both (i) not material and (ii) the type that the registrant treats as private or confidential.

First Amendment to Development and Supply Agreement dated April 17, 2008 between Seagen Inc. and Abbott Laboratories.

ex103abbottsgn-30manufac [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL.

First Amendment to Commercial Supply Agreement, dated February 7, 2023, between Seagen Inc. and Hovione FarmaCiencia SA.

ex108hovioneedactedforct 1 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934

DEFM14A Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934

PREM14A Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

CALCULATION OF FILING FEE TABLES Schedule 14A (Form Type) Seagen Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Transaction Valuation Proposed Maximum Aggregate Value of Transaction Fee Rate Amount of Filing Fee Fees to be Paid

EX-FILING FEES Exhibit 107 CALCULATION OF FILING FEE TABLES Schedule 14A (Form Type) Seagen Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 3, 2023 Seagen Inc. (Exact

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 3, 2023 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 12, 2023 Seagen Inc. (Exact

DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 12, 2023 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (C

SGEN / Seagen Inc / BAKER BROS. ADVISORS LP - SC 13D/A Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 33) Seagen Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 812578102 (CUSIP Number) Alexandra A. Toohey Chief Financial Officer Baker Bros. Advisors LP 860 Washington Street, 3rd Floor New York, NY 10014 (212) 33

certain specified persons identified therein in their respective capacities as record or beneficial owners of Seagen common stock.

EX-10.1 3 d467472dex101.htm EX-10.1 Exhibit 10.1 VOTING AGREEMENT This VOTING AGREEMENT (this “Agreement”), dated as of March 12, 2023, is by and among (i) Pfizer Inc., a Delaware corporation (“Parent”), (ii) Seagen Inc., a Delaware corporation (the “Company”), and (iii) Baker Bros. Advisors LP (the “Advisor”), on behalf of itself and the persons listed on Schedule A hereto in their capacity as re

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 12, 2023 Seagen Inc. (Exact

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 12, 2023 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commissio

Pfizer Invests $43 Billion to Battle Cancer

EX-99.1 Exhibit 99.1 Pfizer Invests $43 Billion to Battle Cancer • Pfizer to acquire Seagen for $229 per Seagen share in cash, for a total enterprise value of approximately $43 billion • Proposed combination enhances Pfizer’s position as a leading company in Oncology • Seagen’s medicines, late-stage development programs and pioneering expertise in Antibody-Drug Conjugates (ADCs) strongly complemen

Form of Letter Agreement,

EX-10.2 Exhibit 10.2 EXECUTION March 12, 2023 [David Epstein/Roger D. Dansey, M.D.] At the address on file with the Company Dear [David/Roger]: This letter agreement (this “Agreement”) confirms the understanding between you and Seagen Inc. (the “Company”) regarding certain payments that you may become entitled to receive in connection with the proposed acquisition (the “Acquisition”) of the Compan

Agreement and Plan of Merger, dated March 12, 2023, by and among Seagen Inc., Pfizer Inc. and Aris Merger Sub, Inc.

EX-2.1 Exhibit 2.1 EXECUTION VERSION AGREEMENT AND PLAN OF MERGER by and among PFIZER INC., ARIS MERGER SUB, INC. and SEAGEN INC., Dated as of MARCH 12, 2023 Table of Contents Page Section 1 - THE MERGER 1 1.1 The Merger 1 1.2 Effective Time 2 1.3 The Closing 2 1.4 Directors and Officers of the Corporation 2 1.5 Subsequent Actions 2 Section 2 - CONVERSION OF SECURITIES 3 2.1 Conversion of Shares 3

Forward Looking Statements and Other Notices Our discussions during this conference call will include forward-looking information about, among other topics, Pfizer’s proposed acquisition of Seagen, Pfizer’s and Seagen’s commercialized and pipeline pr

EX-99.2 Exhibit 99.2 Pfizer Invests $43B to Battle Cancer March 13, 2023 Breakthroughs that change patients’ lives 1 Forward Looking Statements and Other Notices Our discussions during this conference call will include forward-looking information about, among other topics, Pfizer’s proposed acquisition of Seagen, Pfizer’s and Seagen’s commercialized and pipeline products, including anticipated lau

Amendment to the Collaboration Agreement between Seagen Inc. and Takeda Manufacturing U.S.A., Inc. dated November 7, 2022.

ex102-amendmenttocollabo [*] = Certain confidential information contained in this document, marked by brackets, has been omitted because it is both (i) not material and (ii) is the type that the registrant treats as private or confidential.

Seagen Reports Fourth Quarter and Full Year 2022 Financial Results -Total Revenues of $2.0 Billion in 2022, Including 23 Percent Annual Increase in Total Net Product Sales to $1.7 Billion- -TUKYSA Granted FDA Accelerated Approval for Previously Treat

EX-99.1 2 ex-9912022q4.htm EX-99.1 Exhibit 99.1 Seagen Reports Fourth Quarter and Full Year 2022 Financial Results -Total Revenues of $2.0 Billion in 2022, Including 23 Percent Annual Increase in Total Net Product Sales to $1.7 Billion- -TUKYSA Granted FDA Accelerated Approval for Previously Treated RAS Wild-Type, HER2-Positive Metastatic Colorectal Cancer- -ADCETRIS Received Pediatric Indication

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 15, 2023 SEAGEN INC. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commis

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 0-32405 SEAGEN INC. (Exa

Form of Global Performance Stock Option Grant Notice and Global Performance Stock Option Agreement under the Amended and Restated 2007 Equity Incentive Plan (approved November 8, 2022).

ex1085-formofperformance EXHIBIT 10.85 1. 11-8-2022 SEAGEN INC. GLOBAL STOCK OPTION GRANT NOTICE (AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN) Seagen Inc. (the “Company”), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the “Plan”), hereby awards to Optionee an option to purchase Shares set forth below (the “Option”). The Option is subject to all of the terms and conditions as

Subsidiaries of Seagen Inc.

EX-21.1 6 ex-211202210xk.htm EX-21.1 Exhibit 21.1 Subsidiaries of Seagen Inc. Name Jurisdiction of Incorporation East Coast Ventures, Inc. Delaware Seagen Australia Pty Limited Australia Seagen Austria GmbH Austria Seagen B.V. Netherlands Seagen Canada Inc. Canada Seagen Denmark ApS Denmark Seagen France SAS France Seagen Germany GmbH Germany Seagen International GmbH Switzerland SeaGen Internatio

Amended and Restated Employment Agreement dated

[*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL.

Employment Agreement dated November 8, 2022, between Seagen Inc. and David Epstein.

EX-10.41 3 ex1041-espteinemployment.htm EX-10.41 [*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. Exhibit 10.41 EXECUTION VERSION EXECUTIVE EMPLOYMENT AGREEMENT THIS EXECUTIVE EMPLOYMENT AGREEMENT (this “Agreement”) is made and enter

SGEN / Seattle Genetics, Inc. / Capital International Investors - SEC SCHEDULE 13G Passive Investment

SC 13G/A 1 SEC13GFiling.htm SEC SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 7 )* Seagen Inc. (Name of Issuer) Common Stock (Title of Class of Securities) 81181C104 (CUSIP Number) December 30, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designa

PIRS / Pieris Pharmaceuticals Inc / Seagen Inc. - SC 13G/A Passive Investment

SC 13G/A SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.

SGEN / Seattle Genetics, Inc. / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 6)* Name of issuer: Seagen Inc. Title of Class of Securities: Common Stock CUSIP Number: 81181C104 Date of Event Which Requires Filing of this Statement: December 30, 2022 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ☒ Rule 13

SGEN / Seattle Genetics, Inc. / WELLINGTON MANAGEMENT GROUP LLP - SEC SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1 )* Seagen Inc. (Name of Issuer) Common Stock (Title of Class of Securities) 81181C104 (CUSIP Number) December 30, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule i

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 19, 2023 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commiss

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 17, 2022 Seagen Inc. (Ex

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 17, 2022 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commis

Amended and Restated Bylaws of Seagen Inc.

Exhibit 3.1 AMENDED AND RESTATED BYLAWS OF SEAGEN INC. AS AMENDED AND RESTATED EFFECTIVE NOVEMBER 17, 2022 TABLE OF CONTENTS Page ARTICLE I MEETINGS OF STOCKHOLDERS 1 1.1 Place of Meetings 1 1.2 Annual Meeting 1 1.3 Special Meeting 1 1.4 Notice of Stockholder?s Meetings; Affidavit of Notice; Special Meetings Called by Stockholders 1 1.5 Advance Notice of Stockholder Nominees and Other Stockholder

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 8, 2022 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commiss

Form of Global Performance Stock Unit Grant Notice and Global Performance Stock Unit Agreement under the Amended and Restated 2007 Equity Incentive Plan (approved August 15, 2022).

ex-105xfor10xqfilingxfor SEAGEN INC. GLOBAL PERFORMANCE STOCK UNIT GRANT NOTICE (AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN) Seagen Inc. (the “Company”), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the “Plan”), hereby awards to Participant a Stock Unit Award for the number of stock units set forth below (the “Award”). The Award is subject to all of the terms and condition

Seagen Reports Third Quarter 2022 Financial Results -Total Revenues of $510 Million in 3Q22, Including Net Product Sales of $428 Million- -Submitted Supplemental Biologics License Application to FDA for PADCEV in Combination with KEYTRUDA as First-Li

Exhibit 99.1 Seagen Reports Third Quarter 2022 Financial Results -Total Revenues of $510 Million in 3Q22, Including Net Product Sales of $428 Million- -Submitted Supplemental Biologics License Application to FDA for PADCEV in Combination with KEYTRUDA as First-Line Treatment for Advanced Urothelial Cancer- -Announced FDA Granted Priority Review for TUKYSA in Combination with Trastuzumab for Previo

Form of French-Qualified Stock Unit Grant Notice and French-Qualified Stock Unit Agreement under the Amended and Restated 2007 Equity Incentive Plan (approved August 15, 2022).

ex-107for10xqfilingxform 8-15-2022 SEAGEN INC. FRENCH-QUALIFIED RESTRICTED STOCK UNIT GRANT NOTICE Seagen Inc. (the “Company”), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the “U.S. Plan”) and the Rules of the Seagen Inc. Amended and Restated 2007 Equity Incentive Plan for Stock Units granted to French Grantees (the “French RSU Sub-Plan;” together with the U.S. Plan, the “Plan

Form of Global Stock Option Grant Notice and Global Stock Option Agreement under the Amended and Restated 2007 Equity Incentive Plan (approved August 15, 2022).

ex-106for10xqfilingxform 1. 8-15-2022 SEAGEN INC. GLOBAL STOCK OPTION GRANT NOTICE (AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN) Seagen Inc. (the “Company”), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the “Plan”), hereby awards to Optionee an option to purchase Shares set forth below (the “Option”). The Option is subject to all of the terms and conditions as set forth her

Form of Global Stock Unit Grant Notice and Global Stock Unit Agreement under the Amended and Restated 2007 Equity Incentive Plan (approved August 15, 2022).

ex-104for10xqfilingxform SEAGEN INC. GLOBAL STOCK UNIT GRANT NOTICE (AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN) Seagen Inc. (the “Company”), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the “Plan”), hereby awards to Participant a Stock Unit Award for the number of stock units set forth below (the “Award”). The Award is subject to all of the terms and conditions as set for

Seventh Amendment to Development and Supply Agreement dated January 2, 2013 between Seagen Inc.

ex-102xseagenxabbottxfor 1/4 Exhibit 10.2 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. SEVENTH AMENDMENT TO DEVELOPMENT AND SUPPLY AGREEMENT Effective as of date of the last signature below, Abbott Laboratories, an Illinois cor

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 27, 2022 SEAGEN INC. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commiss

License and Collaboration Agreement, effective October 7, 2011, between Genmab A/S and Seagen

ex-101seagenxgenmabxforu Exhibit 10.1 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. Execution Copy LICENSE AND COLLABORATION AGREEMENT by and between Seattle Genetics, Inc. and Genmab A/S Effective as of: October 7, 2011 CONTENT

Second Amendment to the Collaboration and License Agreement between Seagen Inc. and Agensys, Inc. dated effective January 1, 2022.

ex-103astxsecondamendmen Second Amendment to Collaboration and License Agreement 1 [*] = Certain confidential information contained in this document, marked by brackets, has been omitted because it is both (i) not material and (ii) is the type that the registrant treats as private or confidential.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file numbe

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 12, 2022 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commissi

Seagen Statement on Outcome of Daiichi Sankyo Arbitration

Exhibit 99.1 Seagen Statement on Outcome of Daiichi Sankyo Arbitration BOTHELL, Wash. ? August 12, 2022 ? Seagen Inc. (Nasdaq: SGEN) today issued a statement regarding the outcome of the arbitration with Daiichi Sankyo Co. Ltd. (?Daiichi Sankyo?) relating to the parties? 2008 collaboration agreement for the use of Seagen?s antibody-drug conjugate (ADC) technology. The arbitrator ruled in favor of

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 28, 2022 SEAGEN INC. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 0-3

Thirteenth Amendment to Development and Supply Agreement, effective May 12, 2022 between Seagen Inc. (f/k/a Seattle Genetics, Inc.) and AbbVie Inc. (formerly part of Abbott Laboratories Inc.)

[ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL.

Seagen Reports Second Quarter 2022 Financial Results -Total Revenues of $498 Million in 2Q22, Including Net Product Sales of $432 Million- -Announced Positive Topline Results for PADCEV with KEYTRUDA as First-Line Treatment for Advanced Urothelial Ca

Exhibit 99.1 Seagen Reports Second Quarter 2022 Financial Results -Total Revenues of $498 Million in 2Q22, Including Net Product Sales of $432 Million- -Announced Positive Topline Results for PADCEV with KEYTRUDA as First-Line Treatment for Advanced Urothelial Cancer- -Presented Positive Results from Pivotal MOUNTAINEER Trial Demonstrating Antitumor Activity of TUKYSA in Combination with Trastuzum

Amendment No. 1 to Commercial Supply Agreement dated June 17, 2022 between Seagen Inc. (f/k/a Seattle Genetics, Inc.) and Corden Pharma GmbH.

271998166 v2 [*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL.

Seagen and Astellas Announce Positive Topline Results For PADCEV® (enfortumab vedotin-ejfv) with KEYTRUDA® (pembrolizumab) as First-Line Treatment for Advanced Urothelial Cancer – Companies plan to discuss results with regulatory authorities –

Exhibit 99.1 Seagen and Astellas Announce Positive Topline Results For PADCEV? (enfortumab vedotin-ejfv) with KEYTRUDA? (pembrolizumab) as First-Line Treatment for Advanced Urothelial Cancer ? Companies plan to discuss results with regulatory authorities ? BOTHELL, Wash. and TOKYO?July 26, 2022?Seagen Inc. (Nasdaq:SGEN) and Astellas Pharma Inc. (TSE:4503, President and CEO: Kenji Yasukawa, Ph.D.,

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 26, 2022 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 5, 2022 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organiz

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 23, 2022 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

Seagen Announces Positive Topline Results of Pivotal Phase 2 Clinical Trial of TUKYSA® (tucatinib) in Combination With Trastuzumab in HER2-Positive Metastatic Colorectal Cancer - Data Accepted for Presentation at ESMO World Congress on Gastrointestin

EX-99.1 Exhibit 99.1 Seagen Announces Positive Topline Results of Pivotal Phase 2 Clinical Trial of TUKYSA® (tucatinib) in Combination With Trastuzumab in HER2-Positive Metastatic Colorectal Cancer - Data Accepted for Presentation at ESMO World Congress on Gastrointestinal Cancer - BOTHELL, Wash.-May 23, 2022—Seagen Inc. (Nasdaq:SGEN) today announced positive topline results from the pivotal phase

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 13, 2022 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 15, 2022 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

[Signature Page Follows]

Exhibit 99.1 EXECUTION May 15, 2022 Clay B. Siegall in care of Seagen Inc. Dear Clay: This letter agreement (this ?Letter Agreement?) memorializes your separation from Seagen Inc. (together with its subsidiaries and affiliates, the ?Company?). All capitalized terms that are not defined in this Letter Agreement are used with the meanings assigned in the Amended and Restated Executive Employment Agr

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 5, 2022 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission F

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 28, 2022 SEAGEN INC. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commissio

Form of Stock Option Agreement for Non-Employee Directors under the Amended and Restated 2007 Equity Incentive Plan (approved February 10, 2022).

Exhibit 10.9 1 2-10-2022 SEAGEN INC. AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN NOTICE OF STOCK OPTION GRANT ?Name? ?Title? ?CompanyInstitute? ?Address? ?Address2? ?CityStateZip? Dear ?Salutation?: You have been granted an option to purchase Common Stock of Seagen Inc. as follows: Date of Grant [] Exercise Price per Share [$] Total Number of Shares Granted [] Type of Option Nonstatutory Stock

Form of Stock Unit Grant Notice and Stock Unit Agreement for Non-employee Directors under the Amended and Restated 2007 Equity Incentive Plan (Approved February 10, 2022)

Exhibit 10.8 2-10-2022 SEAGEN INC. STOCK UNIT GRANT NOTICE (AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN) Seagen Inc. (the ?Company?), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the ?Plan?), hereby awards to Participant a Stock Unit Award for the number of stock units set forth below (the ?Award?). The Award is subject to all of the terms and conditions as set forth herein

Seagen Reports First Quarter 2022 Financial Results -Total Revenues of $426 Million in 1Q22, Including Net Product Sales of $383 Million- -PADCEV® Approved by European Commission for Previously Treated Locally Advanced or Metastatic Urothelial Cancer

Exhibit 99.1 Seagen Reports First Quarter 2022 Financial Results -Total Revenues of $426 Million in 1Q22, Including Net Product Sales of $383 Million- -PADCEV? Approved by European Commission for Previously Treated Locally Advanced or Metastatic Urothelial Cancer- -ADCETRIS? Overall Survival Data in Newly Diagnosed Advanced Hodgkin Lymphoma Patients to be Presented in Oral Session at ASCO Annual M

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2022 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 0-

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 12, 2022 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commissio

Amended and Restated Bylaws of Seagen Inc.

Exhibit 3.1 AMENDED AND RESTATED BYLAWS OF SEAGEN INC. AS AMENDED AND RESTATED EFFECTIVE APRIL 12, 2022 TABLE OF CONTENTS Page ARTICLE I MEETINGS OF STOCKHOLDERS 1 1.1 Place of Meetings 1 1.2 Annual Meeting 1 1.3 Special Meeting 1 1.4 Notice of Stockholder?s Meetings; Affidavit of Notice; Special Meetings Called by Stockholders 1 1.5 Advance Notice of Stockholder Nominees and Other Stockholder Pro

Seagen Announces Jury Award in Patent Infringement Case Against Daiichi Sankyo - Jury Upholds Validity of Asserted Claims of the Patent, Finds Willful Infringement and Issues Past Damages Award of $41.82 Million – - Seagen to Request Royalty on Futur

Exhibit 99.1 FOR IMMEDIATE RELEASE Friday, April 8, 2022 Seagen Announces Jury Award in Patent Infringement Case Against Daiichi Sankyo - Jury Upholds Validity of Asserted Claims of the Patent, Finds Willful Infringement and Issues Past Damages Award of $41.82 Million ? - Seagen to Request Royalty on Future U.S. Sales of Enhertu? Through the Life of the Patent - - Separate Arbitration Proceedings

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 8, 2022 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ? Filed by a Party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ? Filed by a Party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 7, 2022 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

PROCEEDS AGREEMENT

Exhibit 99.2 PROCEEDS AGREEMENT AGREEMENT dated as of March 8, 2022 by and between Baker Bros. Advisors LP (the ?Management Company?) and Felix Baker (the ?Agent?). WHEREAS, the Agent, in his capacity as a director of Seagen Inc. (the ?Company?), received non-transferable options (the ?Options?) to purchase 17,500 shares of the Company common stock (the ?Stock?) according to the below Schedule A;

Loan Agreement Between Baker Brothers Life Sciences, L.P., 667, L.P., and Baker Bros. Advisors LP

Exhibit 99.1 Loan Agreement Between Baker Brothers Life Sciences, L.P., 667, L.P., and Baker Bros. Advisors LP For value received, Baker Bros. Advisors LP (the ?Management Company?) promises to pay Baker Brothers Life Sciences, L.P., and 667, L.P., (collectively ?The Funds?), the amounts set forth in Schedule A below, payable on the Due Date (as defined below) with interest payable through the Due

SGEN / Seattle Genetics, Inc. / BAKER BROS. ADVISORS LP - SC 13D/A Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 32) Seagen Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 812578102 (CUSIP Number) Alexandra A. Toohey Chief Financial Officer Baker Bros. Advisors LP 860 Washington Street, 3rd Floor New York, NY 10014 (212) 33

SGEN / Seattle Genetics, Inc. / Capital International Investors - SEC SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 6 )* Seagen Inc. (Name of Issuer) Common Stock (Title of Class of Securities) 81181C104 (CUSIP Number) December 31, 2021 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule i

SGEN / Seattle Genetics, Inc. / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 5)* Name of issuer: Seagen Inc. Title of Class of Securities: Common Stock CUSIP Number: 81181C104 Date of Event Which Requires Filing of this Statement: December 31, 2021 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ??Rule 13

Subsidiaries of Seagen Inc.

Exhibit 21.1 Subsidiaries of Seagen Inc. Name Jurisdiction of Incorporation Cascadian Therapeutics, LLC Delaware East Coast Ventures, Inc. Delaware Seagen Australia Pty Limited Australia Seagen Austria GmbH Austria Seagen B.V. Netherlands Seagen Canada Inc. Canada Seagen Denmark ApS Denmark Seagen France SAS France Seagen Germany GmbH Germany Seagen International GmbH Switzerland SeaGen Internatio

Form of Performance-Based Stock Unit Grant Notice and Stock Unit Agreement under the Amended and Restated 2007 Equity Incentive Plan (approved January 18, 2022)

Exhibit 10.118 SEAGEN INC. STOCK UNIT GRANT NOTICE (AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN) Seagen Inc. (the ?Company?), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the ?Plan?), hereby awards to Participant a Stock Unit Award for the number of stock units set forth below (the ?Award?). The Award is subject to all of the terms and conditions as set forth herein and in

Seagen Reports Fourth Quarter and Full Year 2021 Financial Results -Total Revenues of $1.6 Billion in 2021, Including 38 Percent Annual Increase in Total Net Product Sales to $1.4 Billion- -Growth Across Commercial Portfolio of Four Oncology Products

Exhibit 99.1 Seagen Reports Fourth Quarter and Full Year 2021 Financial Results -Total Revenues of $1.6 Billion in 2021, Including 38 Percent Annual Increase in Total Net Product Sales to $1.4 Billion- -Growth Across Commercial Portfolio of Four Oncology Products- -ADCETRIS? (brentuximab vedotin) Combination Significantly Improves Overall Survival in Newly Diagnosed Patients with Advanced Hodgkin

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K (Mark One) ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 0-3240

Amended and Restated Employment Agreement dated

AMENDED & RESTATED EXECUTIVE EMPLOYMENT AGREEMENT THIS AMENDED & RESTATED EXECUTIVE EMPLOYMENT AGREEMENT (?Agreement?) is made and entered into as of February 9, 2022 by and between SEAGEN INC.

Amended and Restated Employment Agreement dated

AMENDED & RESTATED EXECUTIVE EMPLOYMENT AGREEMENT THIS AMENDED & RESTATED EXECUTIVE EMPLOYMENT AGREEMENT (?Agreement?) is made and entered into as of February 9, 2022 by and between SEAGEN INC.

Tenth Amendment to Development and Supply Agreement, effective as of December 26, 2016 between

1/6 Exhibit 10.33 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. TENTH AMENDMENT TO DEVELOPMENT AND SUPPLY AGREEMENT Effective as of the date of the last signature below, AbbVie Inc. (the successor in interest to Abbott Laborator

Amended and Restated Employment Agreement dated

AMENDED & RESTATED EXECUTIVE EMPLOYMENT AGREEMENT THIS AMENDED & RESTATED EXECUTIVE EMPLOYMENT AGREEMENT (?Agreement?) is made and entered into as of February 9, 2022 by and between SEAGEN INC.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 9, 2022 SEAGEN INC. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commiss

Collaboration and License Agreement dated January 7, 2007 between

1/84 Exhibit 10.2 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. COLLABORATION AND LICENSE AGREEMENT This Agreement is entered into as of January 7, 2007 by and between: SEATTLE GENETICS, INC., a Delaware corporation, having its

Amended and Restated Employment Agreement dated

AMENDED & RESTATED EXECUTIVE EMPLOYMENT AGREEMENT THIS AMENDED & RESTATED EXECUTIVE EMPLOYMENT AGREEMENT (?Agreement?) is made and entered into as of February 9, 2022 by and between SEAGEN INC.

Amended and Restated Employment Agreement dated February 9, 2022, between Seagen Inc. and Todd Simpson.

AMENDED & RESTATED EXECUTIVE EMPLOYMENT AGREEMENT THIS AMENDED & RESTATED EXECUTIVE EMPLOYMENT AGREEMENT (?Agreement?) is made and entered into as of February 9, 2022 by and between SEAGEN INC.

Amended and Restated Employment Agreement dated February 9, 2022, between Seagen Inc. and

AMENDED & RESTATED EXECUTIVE EMPLOYMENT AGREEMENT THIS AMENDED & RESTATED EXECUTIVE EMPLOYMENT AGREEMENT (?Agreement?) is made and entered into as of February 9, 2022 by and between SEAGEN INC.

SGEN / Seattle Genetics, Inc. / WELLINGTON MANAGEMENT GROUP LLP - SEC SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Seagen Inc. (Name of Issuer) Common Stock (Title of Class of Securities) 81181C104 (CUSIP Number) December 31, 2021 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 23, 2021 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commis

Form of Performance-Based Stock Unit Grant Notice and Stock Unit Agreement for employees under the Amended and Restated 2007 Equity Incentive Plan (approved August 16, 2021).

EX-10.3 4 ex103.htm EX-10.3 Exhibit 10.3 SEAGEN INC. STOCK UNIT GRANT NOTICE (AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN) Seagen Inc. (the “Company”), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the “Plan”), hereby awards to Participant a Stock Unit Award for the number of stock units set forth below (the “Award”). The Award is subject to all of the terms and conditions a

Seagen Reports Third Quarter 2021 Financial Results -Total Net Product Sales of $366.5 Million in 3Q21, an Increase of 37 Percent Over 3Q20- -FDA Granted TIVDAK Accelerated Approval for Previously Treated Recurrent or Metastatic Cervical Cancer- -Com

Exhibit 99.1 Seagen Reports Third Quarter 2021 Financial Results -Total Net Product Sales of $366.5 Million in 3Q21, an Increase of 37 Percent Over 3Q20- -FDA Granted TIVDAK Accelerated Approval for Previously Treated Recurrent or Metastatic Cervical Cancer- -Completed Enrollment in both PADCEV EV-103 Trial Cohort K in First-Line Metastatic Urothelial Cancer and in TUKYSA MOUNTAINEER Trial in Prev

Form of Stock Unit Grant Notice and Stock Unit Agreement for Non-U.S. Participants under the Amended and Restated 2007 Equity Incentive Plan (approved August 16, 2021).

Exhibit 10.7 SEAGEN INC. STOCK UNIT GRANT NOTICE FOR NON-US PARTICIPANTS (AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN) Seagen Inc. (the ?Company?), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the ?Plan?), hereby awards to Participant a Stock Unit Award for the number of stock units set forth below (the ?Award?). The Award is subject to all of the terms and conditions as se

Ninth Amendment to Development and Supply Agreement effective as of August 28, 2016 between Seagen Inc. (f/k/a Seattle Genetics, Inc.) and AbbVie Inc. (formerly part of Abbott Laboratories Inc.)

1/5 Exhibit 10.1 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. NINTH AMENDMENT TO DEVELOPMENT AND SUPPLY AGREEMENT Effective as of the date of the last signature below, AbbVie Inc. (the successor-in-interest to Abbott Laboratori

Form of Stock Unit Grant Notice and Stock Unit Agreement for U.S. Participants under the Amended and Restated 2007 Equity Incentive Plan (approved August 16, 2021).

Exhibit 10.6 SEAGEN INC. STOCK UNIT GRANT NOTICE (AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN) Seagen Inc. (the ?Company?), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the ?Plan?), hereby awards to Participant a Stock Unit Award for the number of stock units set forth below (the ?Award?). The Award is subject to all of the terms and conditions as set forth herein and in th

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file numbe

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 28, 2021 SEAGEN INC. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commiss

Form of Stock Option Agreement for U.S. Participants under the Amended and Restated 2007 Equity Incentive Plan (approved August 16, 2021).

Exhibit 10.4 SEAGEN INC. AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN STOCK OPTION AGREEMENT THIS STOCK OPTION AGREEMENT (this ?Agreement?) dated %%OPTIONDATE,'MM/DD/YYYY'%-% (?Grant Date?) between Seagen Inc., a Delaware corporation (the ?Company?), and %%FIRSTNAME%-% %%MIDDLENAME%-% %%LASTNAME%-% (?Optionee?), is entered into as follows: WITNESSETH: WHEREAS, the Company has established the Am

Form of Stock Option Agreement for Non-U.S. Participants under the Amended and Restated 2007 Equity Incentive Plan (approved August 16, 2021).

Exhibit 10.5 1. SEAGEN INC. AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN STOCK OPTION AGREEMENT FOR NON-US PARTICIPANTS THIS STOCK OPTION AGREEMENT (the ?Agreement?) dated %%OPTIONDATE,?MM/DD/YYYY?%-% (?Grant Date?) between Seagen Inc., a Delaware corporation (the ?Company?), and %%FIRSTNAME%-% %%MIDDLENAME%-% %%LASTNAME%-% (?Optionee?), is entered into as follows: WITNESSETH: WHEREAS, the Comp

Commercial Supply Agreement between Hovione Farmaciencia, SA and Seagen Inc. dated July 1, 2021.

[ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL.

Financial Statements and Exhibits, Completion of Acquisition or Disposition of Assets

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 15, 2021 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commi

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 20, 2021 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commi

Seagen and Genmab Announce FDA Accelerated Approval for TIVDAK™ (tisotumab vedotin-tftv) in Previously Treated Recurrent or Metastatic Cervical Cancer - TIVDAK is a First-in-Class Antibody-Drug Conjugate Directed to Tissue Factor, a Protein Expressed

EX-99.1 2 d232532dex991.htm EX-99.1 Exhibit 99.1 Seagen and Genmab Announce FDA Accelerated Approval for TIVDAK™ (tisotumab vedotin-tftv) in Previously Treated Recurrent or Metastatic Cervical Cancer - TIVDAK is a First-in-Class Antibody-Drug Conjugate Directed to Tissue Factor, a Protein Expressed on Cervical Cancer Cells - - New Monotherapy Approved for Use in a Cancer with Limited Treatment Opt

License Agreement dated as of August 8, 2021 between RemeGen Co. Ltd. and Seagen Inc.

[ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL.

Entry into a Material Definitive Agreement

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 8, 2021 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commissio

Lease agreement dated June 12, 2021 between Seagen Inc. and DPIF2 WA 7 Mountain View, LLC.

Exhibit 10.3 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. STANDARD FORM INDUSTRIAL BUILDING LEASE 1. BASIC TERMS. This Section 1 contains the Basic Terms of this Lease between Landlord and Tenant, named below. Other Sections of

Amendment to Joint Commercialization Agreement between Seagen Inc. and Agensys, Inc. effective January 1, 2020.

First Amendment to the Joint Commercialization Agreement 1 Exhibit 10.1 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. FIRST AMENDMENT TO THE JOINT COMMERCIALIZATION AGREEMENT This FIRST AMENDMENT TO THE JOINT COMMERCIALIZATION A

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 29, 2021 SEAGEN INC. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

Seagen Reports Second Quarter 2021 Financial Results -Record Quarterly Sales for Each of ADCETRIS, PADCEV and TUKYSA; Total Net Product Sales of $347.3 Million in 2Q21, an Increase of 44 Percent Over 2Q20- -FDA Grants PADCEV Regular Approval and Adds

Exhibit 99.1 Seagen Reports Second Quarter 2021 Financial Results -Record Quarterly Sales for Each of ADCETRIS, PADCEV and TUKYSA; Total Net Product Sales of $347.3 Million in 2Q21, an Increase of 44 Percent Over 2Q20- -FDA Grants PADCEV Regular Approval and Adds New Indication for Locally Advanced or Metastatic Urothelial Cancer- -Tisotumab Vedotin BLA Under FDA Priority Review with PDUFA Date of

Letter Agreement Regarding Royalty between the University of Miami and Seagen Inc. (f/k/a

1/3 Exhibit 10.2 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. April 11, 2016 Joseph T. Natoli Senior Vice President for Business and Finance and Chief Financial Officer University of Miami 1252 Memorial Drive Ashe Building 230

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 0-3

Entry into a Material Definitive Agreement

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 11, 2021 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

U.S. FDA Grants Regular Approval and Expands Indication for PADCEV® (enfortumab vedotin-ejfv) for Patients with Locally Advanced or Metastatic Urothelial Cancer - Regular Approval Based on Overall Survival Results from Confirmatory EV-301 Trial - - F

Exhibit 99.1 U.S. FDA Grants Regular Approval and Expands Indication for PADCEV? (enfortumab vedotin-ejfv) for Patients with Locally Advanced or Metastatic Urothelial Cancer - Regular Approval Based on Overall Survival Results from Confirmatory EV-301 Trial - - First and Only FDA-Approved Therapy for Urothelial Cancer Patients Who Are Cisplatin-Ineligible and Have Previously Received One or More P

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 9, 2021 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

Entry into a Material Definitive Agreement, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 21, 2021 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 14, 2021 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 31)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 31) Seagen Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 812578102 (CUSIP Number) Alexandra A. Toohey Chief Financial Officer Baker Bros. Advisors LP 860 Washington Street, 3rd Floor New York, NY 10014 (212) 33

Proceeds Agreement, dated May 14, 2021, by and among the Adviser and Felix J. Baker.

Exhibit 99.2 PROCEEDS AGREEMENT AGREEMENT dated as of May 14, 2021 by and between Baker Bros. Advisors LP (the “Management Company”) and Felix Baker (the “Agent”). WHEREAS, the Agent, in his capacity as a director of Seagen Inc. (the “Company”), received non-transferable options (the “Options”) to purchase 17,500 shares of the Company common stock (the “Stock”) according to the below Schedule A; W

Loan Agreement, dated May 14, 2021, by and among the Adviser and the Funds

Exhibit 99.1 Loan Agreement Between Baker Brothers Life Sciences, L.P., 667, L.P., and Baker Bros. Advisors LP For value received, Baker Bros. Advisors LP (the “Management Company”) promises to pay Baker Brothers Life Sciences, L.P., and 667, L.P., (collectively “The Funds”), the amounts set forth in Schedule A below, payable on the Due Date (as defined below) with interest payable through the Due

Quarterly Report - 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 0-

Form of Stock Option Agreement for U.S. Participants under the Amended and Restated 2007 Equity Incentive Plan (approved March 8, 2021).

Exhibit 10.4 SEAGEN INC. AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN STOCK OPTION AGREEMENT THIS STOCK OPTION AGREEMENT (the ?Agreement?) dated %%OPTIONDATE,'MM/DD/YYYY'%-% (?Grant Date?) between Seagen Inc., a Delaware corporation (the ?Company?), and %%FIRSTNAME%-% %%MIDDLENAME%-% %%LASTNAME%-% (?Optionee?), is entered into as follows: WITNESSETH: WHEREAS, the Company has established the Ame

Form of Stock Option Agreement for Non-Employee Directors under the Amended and Restated 2007 Equity Incentive Plan (approved March 8, 2021).

Exhibit 10.6 SEAGEN INC. AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN NOTICE OF STOCK OPTION GRANT ?Name? ?Title? ?CompanyInstitute? ?Address? ?Address2? ?CityStateZip? Dear ?Salutation?: You have been granted an option to purchase Common Stock of Seagen Inc. as follows: Date of Grant [] Vesting Commencement Date [] Exercise Price per Share [$] Total Number of Shares Granted [] Type of Option N

Form of Stock Option Agreement for Non-U.S. Participants under the Amended and Restated 2007 Equity Incentive Plan (approved March 8, 2021).

Exhibit 10.5 1. 3-8-2021 SEAGEN INC. AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN STOCK OPTION AGREEMENT FOR NON-US PARTICIPANTS THIS STOCK OPTION AGREEMENT (the ?Agreement?) dated %%OPTIONDATE,?MM/DD/YYYY?%-% (?Grant Date?) between Seagen Inc., a Delaware corporation (the ?Company?), and %%FIRSTNAME%-% %%MIDDLENAME%-% %%LASTNAME%-% (?Optionee?), is entered into as follows: WITNESSETH: WHEREAS,

Seagen Reports First Quarter 2021 Financial Results -Net Product Sales of $302.6 Million in 1Q21, an Increase of 52 Percent Over 1Q20- -Significant Regulatory Progress Across Diverse Oncology Pipeline, Including European Commission Approval of TUKYSA

Exhibit 99.1 Seagen Reports First Quarter 2021 Financial Results -Net Product Sales of $302.6 Million in 1Q21, an Increase of 52 Percent Over 1Q20- -Significant Regulatory Progress Across Diverse Oncology Pipeline, Including European Commission Approval of TUKYSA, Multiple Applications Under Review Globally for PADCEV, and FDA Acceptance of Tisotumab Vedotin BLA- -Conference Call Today at 4:30 p.m

Form of Stock Unit Grant Notice and Stock Unit Agreement for French Grantees under the Amended and Restated 2007 Equity Incentive Plan (approved March 8, 2021).

Exhibit 10.9 SEAGEN INC. FRENCH-QUALIFIED RESTRICTED STOCK UNIT GRANT NOTICE Seagen Inc. (the ?Company?), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the ?U.S. Plan?) and the Rules of the Seagen Inc. Amended and Restated 2007 Equity Incentive Plan for Stock Units granted to French Grantees (the ?French RSU Sub-Plan;? together with the U.S. Plan, the ?Plan?), hereby awards to G

Form of Time-Based Stock Unit Grant Notice and Stock Unit Agreement for U.S. Participants under the Amended and Restated 2007 Equity Incentive Plan (approved March 8, 2021).

Exhibit 10.7 SEAGEN INC. STOCK UNIT GRANT NOTICE (AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN) Seagen Inc. (the ?Company?), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the ?Plan?), hereby awards to Participant a Stock Unit Award for the number of stock units set forth below (the ?Award?). The Award is subject to all of the terms and conditions as set forth herein and in th

Third Amendment to Lease dated May 9, 2011 between Seagen Inc. (f/k/a Seattle Genetics Inc.) and B&N 141-302, LLC

1/2 Exhibit 10.2 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. THIRD AMENDMENT TO LEASE This THIRD AMENDMENT TO LEASE (this ?Amendment?) between B&N 141-302, LLC, a Washington limited liability company (?Landlord?) and SEATTLE G

Form of Stock Unit Grant Notice and Stock Unit Agreement for Non-U.S. Participants under the Amended and Restated 2007 Equity Incentive Plan (approved March 8, 2021).

Exhibit 10.8 SEAGEN INC. STOCK UNIT GRANT NOTICE FOR NON-US PARTICIPANTS (AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN) Seagen Inc. (the ?Company?), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the ?Plan?), hereby awards to Participant a Stock Unit Award for the number of stock units set forth below (the ?Award?). The Award is subject to all of the terms and conditions as se

Form of Stock Unit Grant Notice and Stock Unit Agreement for non-employee directors under the Amended and Restated 2007 Equity Incentive Plan (approved March 8, 2021).

Exhibit 10.10 SEAGEN INC. STOCK UNIT GRANT NOTICE (AMENDED AND RESTATED 2007 EQUITY INCENTIVE PLAN) Seagen Inc. (the ?Company?), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the ?Plan?), hereby awards to Participant a Stock Unit Award for the number of stock units set forth below (the ?Award?). The Award is subject to all of the terms and conditions as set forth herein and in t

Office lease dated May 9, 2011 between Seagen Inc. (f/k/a Seattle Genetics Inc.) and WCM Highlands II LLC.

Exhibit 10.1 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. OFFICE LEASE REFERENCE DATE: May 9th, 2011. This Lease (this ?Lease?) is made and entered into by and between WCM HIGHLANDS II, LLC, a Washington limited liability compa

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 29, 2021 SEAGEN INC. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commissio

Amended and Restated 2000 Employee Stock Purchase Plan, effective March 12, 2021.

Exhibit 10.3 SEAGEN INC. AMENDED AND RESTATED 2000 EMPLOYEE STOCK PURCHASE PLAN Adopted by the Board of Directors: November 16, 2000 Approved by the Stockholders: February 14, 2001 Amended and Restated by the Board of Directors: February 1, 2011 Amended and Restated by the Board of Directors: February 11, 2011 Approved by the Stockholders: May 20, 2011 Amended and Restated by the Board of Director

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Pieris Pharmaceuticals, Inc. (Name of Issuer) Common Stock (Title of Class of Securities) (CUSIP Number) March 24, 2021 (

SC 13G SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ? Filed by a Party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ? Filed by a Party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? Confidential, for Use of the Commission Only (as permitte

SCHEDULE 13G

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 5 )* Seagen Inc. (Name of Issuer) Common Stock (Title of Class of Securities) 81181C104 (CUSIP Number) December 31, 2020 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule i

SCHEDULE 13G

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 5 )* Seagen Inc. (Name of Issuer) Common Stock (Title of Class of Securities) 81181C104 (CUSIP Number) December 31, 2020 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule i

Annual Report - 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K (Mark One) ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2020 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 0-3240

Seattle Genetics, Inc.) and SAFC, an operating division of Sigma-Aldrich, Inc.

Exhibit 10.16 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM IF PUBLICLY DISCLOSED COMMERCIAL SUPPLY AGREEMENT SGD-1006 This Commercial Supply Agreement (this ?Agreement?), effective as of the 1ST day of DECEMBER 2010 (the ?Effective Date?), is entered into by

Joint Commercialization Agreement dated October 19, 2020 between Genmab A/S and Seagen Inc. (f.k.a. Seattle Genetics Inc.).

Execution Version CONFIDENTIAL [*] = Certain information contained in this document, marked by brackets, has been omitted because it is both not material and would be competitively harmful if publicly disclosed.

Specimen Stock Certificate.

THIS CERTIFIES THAT is the owner of CUSIP DATED COUNTERSIGNED AND REGISTERED: COMPUTERSHARE TRUST COMPANY, N.

Subsidiaries of Sea

Exhibit 21.1 Subsidiaries of Seagen Inc. Name Jurisdiction of Incorporation Biomira Management, Inc. Delaware Cascadian Therapeutics Luxembourg S.? r.l. Luxembourg Cascadian Therapeutics Inc. Delaware East Coast Ventures, Inc. Delaware Oncothyreon Canada Unlimited Liability Company Canada ProlX Pharmaceuticals Corporation Delaware Protocell Pharmaceuticals Corporation Delaware Seagen Australia Pty

Senior Executive Annual Bonus Plan, as amended February 9, 2021.

Exhibit 10.66 1. SEAGEN Senior Executive Annual Bonus Plan This Senior Executive Annual Bonus Plan (the ?Plan?) is intended to enhance stockholder value by promoting a connection between the performance of Seagen Inc. (the ?Company?) and the compensation of senior executives of the Company, and to promote retention of participating senior executives. 1. Executives employed by the Company and its d

Sixth Amendment to Development and Supply Agreement dated November 18, 2010 between

Exhibit 10.26 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM IF PUBLICLY DISCLOSED SIXTH AMENDMENT TO DEVELOPMENT AND SUPPLY AGREEMENT Effective as of date of the last signature below, Abbott Laboratories, an Illinois corporation having a principal place of bu

Second Amendment to Commercial Supply Agreement effective as of December 2, 2016 between

Exhibit 10.18 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM IF PUBLICLY DISCLOSED 3050 Spruce Street St. Louis, MO 63103 Tel (800) 448-0471 Fax (314) 286-7817 www.safcglobal.net Second Amendment to SGD-1006 Commercial Supply Agreement executed on 1 December 2

First Amendment to Commercial Supply Agreement effective as of January 20, 2014 between

Exhibit 10.17 [*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM IF PUBLICLY DISCLOSED Inspiring Science Amendment to SGD-1006 Commercial Supply Agreement executed on 1 December 2010. [*] Manufacturing Controls Price Increase 27 August 2013 Vaughn Himes VP, Manufact

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 11, 2021 SEAGEN INC. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commis

Seagen Reports Fourth Quarter and Full Year 2020 Financial Results -Net Product Sales of $1 Billion in 2020, an Increase of 59 Percent Over 2019- -European Medicines Agency's CHMP Adopted Positive Opinion Recommending Approval of TUKYSA for Patients

Exhibit 99.1 Seagen Reports Fourth Quarter and Full Year 2020 Financial Results -Net Product Sales of $1 Billion in 2020, an Increase of 59 Percent Over 2019- -European Medicines Agency's CHMP Adopted Positive Opinion Recommending Approval of TUKYSA for Patients with Locally Advanced or Metastatic HER2-Positive Breast Cancer- -PADCEV U.S. and Global Marketing Applications Planned for 1Q 2021- -Tis

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 4)*

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 4)* Name of issuer: Seagen Inc. Title of Class of Securities: Common Stock CUSIP Number: 81181C104 Date of Event Which Requires Filing of this Statement: December 31, 2020 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ☒ Rule 13

SCHEDULE 13G

SC 13G/A 1 SEC13GFiling.htm SEC SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 2 )* Seagen Inc. (Name of Issuer) Common Stock (Title of Class of Securities) 812578102 (CUSIP Number) December 31, 2020 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designa

Form of Common Stock Warrant Agreement and Warrant Certificate

EX-4.7 Form of Common Stock Warrant Agreement and Warrant Certificate Exhibit 4.7 SEAGEN INC. AND , AS WARRANT AGENT FORM OF COMMON STOCK WARRANT AGREEMENT DATED AS OF SEAGEN INC. FORM OF COMMON STOCK WARRANT AGREEMENT THIS COMMON STOCK WARRANT AGREEMENT (this “Agreement”), dated as of [•], between SEAGEN INC., a Delaware corporation (the “Company”), and [•], a [corporation] [national banking asso

RISK FACTORS

EX-99.1 2 d65012dex991.htm EX-99.1 Exhibit 99.1 Throughout the information in this Exhibit 99.1, unless the context specifies or implies otherwise, the terms “Seagen,” “the Company,” “we,” “us” and “our” refer to Seagen Inc., a Delaware corporation, and its subsidiaries on a consolidated basis. Seagen®, , ADCETRIS®, PADCEV® and TUKYSA® are our registered trademarks in the United States. All other

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 29, 2020 SEAGEN INC. (Exact name of registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation) (Commission File Number

Form of Preferred Stock Warrant Agreement and Warrant Certificate

EX-4.8 Form of Preferred Stock Warrant Agreement and Warrant Certificate Exhibit 4.8 SEAGEN INC. AND , AS WARRANT AGENT FORM OF PREFERRED STOCK WARRANT AGREEMENT DATED AS OF SEAGEN INC. FORM OF PREFERRED STOCK WARRANT AGREEMENT THIS PREFERRED STOCK WARRANT AGREEMENT (this “Agreement”), dated as of [•], between SEAGEN INC., a Delaware corporation (the “Company”), and [•], a [corporation] [national

- S-3ASR

S-3ASR 1 d73090ds3asr.htm S-3ASR Table of Contents As filed with the Securities and Exchange Commission on December 29, 2020 Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM S-3 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 SEAGEN INC. (Exact name of registrant as specified in its charter) Delaware 91-1874389 (State or other jurisdiction

Form of Indenture, between Registrant and one or more trustees to be named

EX-4.5 Exhibit 4.5 SEAGEN INC., Issuer AND [TRUSTEE], Trustee INDENTURE Dated as of [•], 20 Debt Securities TABLE OF CONTENTS PAGE ARTICLE 1 DEFINITIONS 1 Section 1.01 Definitions of Terms 1 ARTICLE 2 ISSUE, DESCRIPTION, TERMS, EXECUTION, REGISTRATION AND EXCHANGE OF SECURITIES 5 Section 2.01 Designation and Terms of Securities 5 Section 2.02 Form of Securities and Trustee’s Certificate 8 Section

Form of Debt Securities Warrant Agreement and Warrant Certificate

EX-4.9 Form of Debt Securities Warrant Agreement and Warrant Certificate Exhibit 4.9 SEAGEN INC. AND , AS WARRANT AGENT FORM OF DEBT SECURITIES WARRANT AGREEMENT DATED AS OF SEAGEN INC. FORM OF DEBT SECURITIES WARRANT AGREEMENT THIS DEBT SECURITIES WARRANT AGREEMENT (this “Agreement”), dated as of [•], between SEAGEN INC., a Delaware corporation (the “Company”), and [•], a [corporation] [national

License and Collaboration Agreement related to ladiratuzumab vedotin dated September 13, 2020 between Seagen Inc. (f.k.a. Seattle Genetics, Inc.) and Merck Sharp & Dohme Corp.

exhibit10110q2020q3 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM IF PUBLICLY DISCLOSED Exhibit 10.

Form of Performance-Based Stock Unit Grant Notice and Stock Unit Agreement under the

Exhibit 10.3 Seattle Genetics, Inc. Stock Unit Grant Notice (Amended and Restated 2007 Equity Incentive Plan) Seattle Genetics, Inc. (the “Company”), pursuant to its Amended and Restated 2007 Equity Incentive Plan (the “Plan”), hereby awards to Participant a Stock Unit Award for the number of stock units set forth below (the “Award”). The Award is subject to all of the terms and conditions as set

Quarterly Report - 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file numbe

Stock Purchase Agreement dated September 13, 2020 between Seagen Inc. (f.k.a. Seattle Genetics, Inc.) and Merck Sharp & Dohme Corp.

exhibit10210q2020q3 [ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM IF PUBLICLY DISCLOSED.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 29, 2020 SEAGEN INC. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commiss

Seagen Reports Third Quarter 2020 Financial Results -Net Product Sales $267.5 Million in 3Q20, an Increase of 60 Percent Over 3Q19- -Collaborations with Merck for Ladiratuzumab Vedotin and TUKYSA; Seagen Received $725M in Upfront Payments and $1B Equ

Exhibit 99.1 Seagen Reports Third Quarter 2020 Financial Results -Net Product Sales $267.5 Million in 3Q20, an Increase of 60 Percent Over 3Q19- -Collaborations with Merck for Ladiratuzumab Vedotin and TUKYSA; Seagen Received $725M in Upfront Payments and $1B Equity Investment- -Positive Data from Two PADCEV Clinical Trials to Support Global Registration Applications and Expand U.S. Indication- -P

Regulation FD Disclosure - 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 19, 2020 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commiss

Financial Statements and Exhibits, Other Events - 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 12, 2020 Seagen Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization) (Commiss

Seagen and Astellas Announce Positive Topline Results from Second Cohort of Patients in Phase 2 Pivotal Trial of PADCEV® (enfortumab vedotin-ejfv) in Advanced Urothelial Cancer - Durable Responses Observed in Patients Who Had Previously Received Immu

EX-99.1 Exhibit 99.1 Seagen and Astellas Announce Positive Topline Results from Second Cohort of Patients in Phase 2 Pivotal Trial of PADCEV® (enfortumab vedotin-ejfv) in Advanced Urothelial Cancer - Durable Responses Observed in Patients Who Had Previously Received Immunotherapy but Were Ineligible for Cisplatin in Locally Advanced or Metastatic Setting - BOTHELL, Wash. and TOKYO — October 12, 20

Certificate of Amendment of Fourth Amended and Restated Certificate of Incorporation of Seagen Inc. (f/k/a Seattle Genetics, Inc.).

EX-3.1 Exhibit 3.1 CERTIFICATE OF AMENDMENT OF FOURTH AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF SEATTLE GENETICS, INC. SEATTLE GENETICS, INC., a corporation organized and existing under and by virtue of the General Corporation Law of the State of Delaware, as amended (the “DGCL”), hereby certifies that: FIRST: The name of the Corporation is Seattle Genetics, Inc. (the “Corporation”). SE

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits - 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 6, 2020 Seattle Genetics, Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization

Financial Statements and Exhibits, Other Events - 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 18, 2020 Seattle Genetics, Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organizat

Seattle Genetics and Astellas Announce PADCEV® (enfortumab vedotin-ejfv) Significantly Improved Overall Survival in Phase 3 Trial in Previously Treated Locally Advanced or Metastatic Urothelial Cancer - Trial Stopped Early Due to Positive Results at

EX-99.1 Exhibit 99.1 Seattle Genetics and Astellas Announce PADCEV® (enfortumab vedotin-ejfv) Significantly Improved Overall Survival in Phase 3 Trial in Previously Treated Locally Advanced or Metastatic Urothelial Cancer - Trial Stopped Early Due to Positive Results at Planned Interim Analysis - - Data Intended to Support Global Registrations and Convert Accelerated to Regular Approval in U.S. -

Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities - 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 12, 2020 Seattle Genetics, Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organizat

Seattle Genetics Appoints Ted W. Love, M.D., to Board of Directors

EX-99.1 Exhibit 99.1 Seattle Genetics Appoints Ted W. Love, M.D., to Board of Directors BOTHELL, Wash. – August 18, 2020 – Seattle Genetics, Inc. (Nasdaq:SGEN) today announced that Ted W. Love, M.D., has been appointed to the company’s Board of Directors. Dr. Love has more than 25 years of global experience in the healthcare and biotechnology/pharmaceutical industry and currently serves as Preside

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K Current Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 14, 2020 Seattle Genetics, Inc. (Exact name of Registrant as specified in its charter) Delaware 0-32405 91-1874389 (State or other jurisdiction of incorporation or organization

Amendment No. 1 to License Agreement dated April 23, 2020 between Cascadian Therapeutics,

Exhibit 10.5 CONFIDENTIAL Amendment No. 1 to License Agreement This Amendment No. 1 to License Agreement (this “Amendment”) is effective as of April 23, 2020 (“Amendment Effective Date”) by and between Cascadian Therapeutics, Inc., a Delaware corporation formerly known as Oncothyreon Inc. (“Oncothyreon”), and Array BioPharma, Inc., a Delaware corporation (“Array”). Background A. Array and Oncothyr

Quarterly Report - 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 0-3

Commercial Supply Agreement dated June 13, 2019 between Seagen Inc. (f.k.a Seattle Genetics, Inc.) and Esteve Quimica, S.A.

[ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM IF PUBLICLY DISCLOSED.

Commercial Supply Agreement dated February 20, 2020 between Seagen Inc. (f.k.a. Seattle Genetics, Inc.) and Corden Plankstadt.

[ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM IF PUBLICLY DISCLOSED.

Amended and Restated Employment Agreement dated April 15, 2020 between Seagen Inc. (f.k.a. Seattle Genetics, Inc.) and Charles Romp.

Exhibit 10.7 AMENDED & RESTATED EXECUTIVE EMPLOYMENT AGREEMENT THIS AMEDED & RESTATED EXECUTIVE EMPLOYMENT AGREEMENT (“Agreement”) is made and entered into as of the 15th day of April, 2020, by and between SEATTLE GENETICS, INC., a Delaware corporation (“Company”) and Charles Romp (“Executive”). RECITALS: A. The Company desires that Executive perform services as Executive Vice President, Commercia

Commercial Supply Agreement dated June 13, 2019 between Seagen Inc. (f.k.a Seattle Genetics, Inc.) and Esteve Quimica, S.A.

[ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM IF PUBLICLY DISCLOSED.