FORM 3

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

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1. Name and Address of Reporting Person * Seth Alpna (Last) (First) (Middle) 21823 30TH DRIVE SE (Street) BOTHELL WA 98021 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 03/15/2018	3. Issuer Name and Ticker or Trading Symbol SEATTLE GENETICS INC /WA [ SGEN ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

	/s/ Jean Liu	03/15/2018
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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POWER OF ATTORNEY
       The undersigned hereby constitutes and appoints Clay 
B. Siegall, Todd A. Simpson and Jean I. Liu, 
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 officer, director, and/or 
person who holds more than 10% of the stock of Seattle 
Genetics, Inc. (the 'Company'), Forms 3, Forms 4 and 
Forms 5 in accordance with Section 16(a) of the Securities 
Exchange Act of 1934, as amended (the 'Exchange Act'), and 
the rules thereunder;
(2)	do and perform any and all acts for and on behalf of 
the undersigned which may be necessary or desirable to 
complete and execute any such Forms 3, Forms 4 or Forms 5 
and timely file any such forms with the United States 
Securities and Exchange Commission and any other authority; 
and
(3)	take any other action of any type whatsoever in 
connection with the foregoing which, in the opinion of such 
attorney-in-fact, may be of benefit to, in the best 
interest of, or legally required by, the undersigned, it 
being understood that the documents executed by such 
attorney-in-fact on behalf of the undersigned, pursuant to 
this Power of Attorney shall be in such form and shall 
contain such terms and conditions as such attorney-in-fact 
may approve in his or her discretion.
       The undersigned hereby grants to each such attorney-
in-fact full power and authority to do and perform any and 
every act and thing whatsoever requisite, necessary or 
proper to be done in the exercise of any of the rights and 
powers herein granted, as fully to all intents and purposes 
as the undersigned might or could do if personally present, 
with full power of substitution or revocation, hereby 
ratifying and confirming all that such attorney-in-fact, or 
his or her substitute or substitutes, shall lawfully do or 
cause to be done pursuant to this power of attorney.  The 
undersigned acknowledges that the foregoing attorneys-in-
fact, in serving in such capacity at the request of the 
undersigned, are not assuming, nor is the Company assuming, 
any of the undersigned?s responsibilities to comply with 
Section 16 of the Exchange Act.
       This Power of Attorney shall remain in full force 
and effect until the undersigned is no longer required to 
file Forms 3, Forms 4, and Forms 5 with respect to the 
undersigned?s holdings of and transactions in securities 
issued by the Company, unless earlier revoked by the 
undersigned in a signed writing delivered to the attorneys-
in-fact.
       The undersigned has caused this Power of Attorney to 
be executed as of this 5th day of March 2018.
       




/s/ Alpna Seth, PhD
Signature

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