Exhibit 10.4



 Exhibit 10.4 
  





 
 December 18, 2015 

Via facsimile: (609) 252-4232 
 Bristol-Myers
Squibb Company 
 PO Box 4000 
 Route 206 & Province
Line Road 
 Princeton, New Jersey 08543-4000 
 Attn:
VP & Assistant General Counsel, Licensing and Business Development 
  

	Re:	Amendment to License Agreement 

 Dear Sir or Madam 

This letter sets forth the agreement of Bristol-Myers Squibb Company (“BMS”) and Seattle Genetics, Inc.
(“SGI”) to amend the License Agreement, dated as of March 30, 1998 (as previously amended, the “Agreement”) as set forth herein. A capitalized term used in this letter without definition has the
meaning set forth in the Agreement. 
 By way of background, the Licensed Technology licensed to SGI under the Agreement includes, among
others, U.S. Patent No. 6,214,345 entitled “Lysosomal-Enzyme Cleavable AntiTumor Drug Conjugates” and its foreign counterpart patents (collectively the “Firestone Patent”). Pursuant to Section 5.2(i) of
the Agreement, Products covered by Licensed Technology relating only to the Firestone Patent (“Firestone Products”) bear a royalty at the rate of [***] percent ([***]%). ADCETRIS® (brentuximab vedotin) (“Adcetris”), which was commercially launched by SGI on August 19, 2011, was a Firestone Product. The Firestone Patent has expired in all
jurisdictions worldwide. 
 For good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the parties
agree as follows: 
 Notwithstanding any other provision of the Agreement to the contrary: 

1. Commencing on January 1, 2016, in lieu of any and all other consideration that may be applicable with regard to Adcetris with respect
to the Licensed Technology, BMS will receive a royalty consisting of [***] percent ([***]%) of the Net Sales of Adcetris throughout the Territory; provided however, the foregoing royalty obligation shall expire and terminate on
August 19, 2021. With respect to the Firestone Products, SGI and BMS waive any argument that the Agreement and/or this amendment is unenforceable in view of the U.S. Supreme Court decisions of Brulotte v. Thys Co. and/or Kimble v. Marvel
Enters. Inc. 
 2. Commencing on the Amendment Effective Date, [***] will be owed to BMS with respect to any Firestone Products other
than Adcetris with respect to the Licensed Technology. 

  
 



 
 21823 - 30th Drive Southeast      Bothell, Washington
98021      Tel: 425.527.4000      Fax: 425.527.4001      www.seattlegenetics.com 

Confidential treatment has been requested for portions of this document. This document omits the information subject to the confidential treatment
request. Omissions are designated as ***. A complete version of this document has been filed separately with the Securities and Exchange Commission. 








 3. Commencing on the Amendment Effective Date and subject to the royalty obligation with respect
to Adcetris described in paragraph 1, the license under the Licensed Technology to make, have made, use, sell, have sold, offer for sale, import and export all Firestone Products will be fully paid up, royalty-free and perpetual throughout the
Territory. For clarity, Section 13.6(c) of the Agreement will not apply to any Firestone Product, including Adcetris. 
 Except as set
forth above, the Agreement remains in full force and effect and is unaffected hereby. 
 BMS and SGI, intending to be legally bound, have
caused this letter to be executed by their authorized representatives effective as of the date first set forth above (“Amendment Effective Date”). 

 

			
	Sincerely,
	
	Seattle Genetics, Inc.
		
	By:	 	 /s/ Clay B. Siegall

	Name:	 	 Clay B. Siegall, Ph.D

	Title:	 	 President & CEO



  

			
	ACCEPTED and AGREED:
	
	Bristol-Myers Squibb Company
		
	By:	 	 /s/ Henry Hadad

	Name:	 	 Henry Hadad

	Title:	 	 SVP & Deputy GC, IP