[*] = 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.  Exhibit 10.1  FOURTEENTH AMENDMENT   TO DEVELOPMENT AND SUPPLY AGREEMENT   Effective as of the date of the last signature below (the “Amendment Effective Date”), AbbVie  Inc. (the successor-in-interest to Abbott Laboratories), a Delaware corporation having a principal place  of business at 1 N Waukegan Road, North Chicago, IL 60064 (“AbbVie”), and Seagen Inc., a Delaware  corporation having a principal place of business at 21823 – 30th Drive Southeast in Bothell,  Washington 98021 (“Seagen”) (individually the “Party” or collectively the “Parties”), agree to the  terms and conditions set forth below (this “Amended and Restated Thirteenth Amendment”).   Capitalized terms used but not defined herein shall have the meaning ascribed to them in the  Agreement (as defined below).    WHEREAS, the Parties are party to that certain Development and Supply Agreement with an  Effective Date of February 23, 2004 for the manufacture of a chimeric anti-CD30 AC10 monoclonal  antibody known as cAC10 Bulk Drug Intermediate (as amended, the “Agreement”);    WHEREAS, the Parties entered into that certain Thirteenth Amendment to Development and  Supply Agreement effective May 12, 2022 (the “Thirteenth Amendment”) which, among other things,  added a Stage 15 to the Project (“Stage 15”); and    WHEREAS, the Parties desire to delete in its entirety the Stage 15 that was added pursuant to  the Thirteenth Amendment and replace it with the Stage 15 attached hereto.    NOW, THEREFORE, in consideration of the mutual covenants and agreements contained  here and for other good and valuable consideration, the receipt and sufficiency of which is hereby  acknowledged, the Parties agree as follows:    1. Incorporation of the Agreement.  All capitalized terms which are used but not otherwise  defined herein shall have the same meanings as set forth in the Agreement. To the extent any terms  and provisions of the Agreement are inconsistent with this Amended and Restated Thirteenth  Amendment, such terms and provisions shall be deemed superseded by this Amended and Restated  Thirteenth Amendment.     2. Process Development Work.  Stage 15 added to the Agreement pursuant to the  Thirteenth Amendment is hereby deleted in its entirety and replaced with the Stage 15 attached hereto  as Attachment 1. The services contemplated by the Stage 15 attached hereto as Attachment 1 are  referred to herein as the “Stage 15 Services”. The Parties agree that AbbVie shall perform the Stage  15 Services pursuant to the terms and conditions of this Fourteenth Amendment, and such Stage 15  Services are hereby added to the Project.    3. Payment Schedule.  As compensation for the Stage 15 Services to be performed by  AbbVie pursuant to this Fourteenth Amendment and the remaining compensation due to AbbVie  pursuant to Stage 14B that was the subject of a previous amendment to the Agreement, Seagen shall  pay to AbbVie on the dates and in the amounts set forth in Attachment 2 hereto.      
 
 
2  CONFIDENTIAL  [*] = 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.  4. Project References.  All references to the Project set forth in the Agreement shall also  be deemed to apply to the Stage performed by AbbVie pursuant to this Fourteenth Amendment.        5. Miscellaneous.  Sections 17, 18, 20, 23 and 26 (and each subsection of each of the  foregoing) of the Agreement shall be deemed to apply to this Fourteenth Amendment mutatis  mutandis.    [signature page follows] 
 
 
3  CONFIDENTIAL  [*] = 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.  IN WITNESS WHEREOF, the Parties have caused this Fourteenth Amendment to be  executed by their duly authorized officers as of the date of the last signature set forth below.    ABBVIE INC.     SEAGEN INC.    By: /s/ Marc O’Donoghue    By:  /s/ Christopher Croson      Name: Marc O’Donoghue    Name: Christopher Croson                     Title: VP, External and Contract Manufacturing Title: Executive Director, Global Manufacturing              Date: __10-May-2023 | 07:46 PDT__________ Date: __10-May-2023 | 06:53 PDT_________     
 
 
4  CONFIDENTIAL  [*] = 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.  Attachment 1    STAGE 15:  [*]      
 
 
5  CONFIDENTIAL  [*] = 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.  Attachment 2  UPDATED SUMMARIZED PAYMENT SCHEDULE (Amendments 12 and 14)  [*]