SEC FORM 4

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

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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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

BAKER FELIX

(Last)

(First)

(Middle)

667 MADISON AVENUE, 21ST FLOOR

(Street)

NEW YORK

US 10065

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
SEATTLE GENETICS INC /WA [ SGEN ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
05/14/2014

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock								77,004⁽¹⁾	D
Common Stock								76,997⁽²⁾	D
Common Stock	05/14/2014		M		10,000	A	$7.26	3,882,076	I	See footnote⁽³⁾⁽⁶⁾⁽¹⁷⁾
Common Stock	05/14/2014		M		10,000	A	$7.26	16,999,872	I	See footnote⁽⁴⁾⁽⁶⁾⁽¹⁷⁾
Common Stock	05/14/2014		M		10,000	A	$7.26	382,860	I	See footnote⁽⁵⁾⁽⁶⁾⁽¹⁷⁾
Common Stock	05/15/2014		P		293	A	$34.1⁽⁷⁾	17,000,165	I	See footnote⁽⁸⁾⁽¹⁷⁾⁽⁶⁾
Common Stock	05/15/2014		P		7	A	$34.1⁽⁷⁾	382,867	I	See footnote⁽⁹⁾⁽⁶⁾⁽¹⁷⁾
Common Stock	05/15/2014		P		20,395	A	$34.2644⁽¹⁰⁾	17,020,560	I	See footnote⁽⁸⁾⁽⁶⁾⁽¹⁷⁾
Common Stock	05/15/2014		P		505	A	$34.2644⁽¹⁰⁾	383,372	I	See footnote⁽⁹⁾⁽⁶⁾⁽¹⁷⁾
Common Stock	05/16/2014		A		3,500	A	$0	3,885,576	I	See footnote⁽¹¹⁾⁽¹²⁾⁽⁶⁾⁽¹⁷⁾
Common Stock	05/16/2014		A		3,500	A	$0	17,024,060	I	See footnote⁽⁸⁾⁽¹¹⁾⁽⁶⁾⁽¹⁷⁾
Common Stock	05/16/2014		A		3,500	A	$0	386,872	I	See footnote⁽⁹⁾⁽¹¹⁾⁽⁶⁾⁽¹⁷⁾
Common Stock	05/16/2014		P		117,879	A	$34.0346⁽¹⁸⁾	17,141,939	I	See footnote⁽⁶⁾⁽⁸⁾⁽¹⁷⁾
Common Stock	05/16/2014		P		2,921	A	$34.0346⁽¹⁸⁾	389,793	I	See footnote⁽⁹⁾⁽⁶⁾⁽¹⁷⁾
Common Stock	05/16/2014		P		46,460	A	$34.0849⁽¹⁹⁾	17,188,399	I	See footnote⁽⁸⁾⁽⁶⁾⁽¹⁷⁾
Common Stock	05/16/2014		P		1,151	A	$34.0849⁽¹⁹⁾	390,944	I	See footnote⁽⁶⁾⁽⁹⁾⁽¹⁷⁾

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Non-Qualified Stock Options (right to buy)	$7.26	05/14/2014		M			10,000	05/16/2005	05/17/2014	Common Stock	10,000	$0	0	I	See Footnote⁽³⁾⁽⁶⁾
Non-Qualified Stock Options (right to buy)	$7.26	05/14/2014		M			10,000	05/16/2005	05/17/2014	Common Stock	10,000	$0	0	I	See Footnote⁽⁴⁾⁽⁶⁾
Non-Qualified Stock Options (right to buy)	$7.26	05/14/2014		M			10,000	05/16/2005	05/17/2014	Common Stock	10,000	$0	0	I	See Footnote⁽⁵⁾⁽⁶⁾
Non-Qualified Stock Options (right to buy)	$34.25	05/16/2014		A		8,750		05/15/2015	05/14/2024	Common Stock	8,750	$0	8,750	I	See Footnote⁽¹³⁾⁽¹⁴⁾⁽⁶⁾
Non-Qualified Stock Options (right to buy)	$34.25	05/16/2014		A		8,750		05/15/2015	05/14/2024	Common Stock	8,750	$0	8,750	I	See Footnote⁽¹³⁾⁽¹⁵⁾⁽⁶⁾
Non-Qualified Stock Options (right to buy)	$34.25	05/16/2014		A		8,750		05/15/2015	05/14/2024	Common Stock	8,750	$0	8,750	I	See Footnote⁽⁶⁾⁽¹³⁾⁽¹⁶⁾

1. Name and Address of Reporting Person^*

BAKER FELIX

(Last)

(First)

(Middle)

667 MADISON AVENUE, 21ST FLOOR

(Street)

NEW YORK

US 10065

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

BAKER JULIAN

(Last)

(First)

(Middle)

667 MADISON AVENUE, 21ST FLOOR

(Street)

NEW YORK

US 10065

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Baker Bros. Advisors (GP) LLC

(Last)

(First)

(Middle)

667 MADISION AVENUE 21ST FLOOR

(Street)

NEW YORK

US 10065

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

BAKER BROS. ADVISORS LP

(Last)

(First)

(Middle)

667 MADISON AVENUE, 21ST FLOOR

(Street)

NEW YORK

US 10065

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

667, L.P.

(Last)

(First)

(Middle)

667 MADISON AVENUE 21ST FLOOR

(Street)

NEW YORK

US 10065

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Baker Brothers Life Sciences LP

(Last)

(First)

(Middle)

667 MADISON AVENUE, 21ST FLOOR

(Street)

NEW YORK

US 10065

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

14159, L.P.

(Last)

(First)

(Middle)

667 MADISION AVENUE, 21ST FLOOR

(Street)

NEW YORK

US 10065

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

Explanation of Responses:

1. Reflects shares of common stock of the Issuer held directly by Felix J. Baker.

2. Reflects shares of common stock of the Issuer held directly by Julian C. Baker.

3. As a result of their ownership interest in Baker Biotech Capital (GP), LLC, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in 10,000 shares of Common Stock of the Issuer received upon the exercise of stock options of the Issuer held by 667, L.P. ("667"), a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667. The policy of the Funds (defined below) and the Adviser (defined below), does not permit employees or principals of the Adviser to receive compensation for serving as Directors of the Issuer. The shares of common stock were received upon exercise of 10,000 stock options that were issued to Felix J. Baker in his capacity as a director of the Issuer. Felix J. Baker, pursuant to the policies of the Adviser, does not have any right to the pecuniary interest in the stock options issued for his service on the Board or the shares of common stock received upon exercise of such stock options. Each of the Funds owns an indirect proportionate pecuniary interest in the shares of common stock received upon exercise of the stock options issued in connection with Felix J. Baker's service on the Board less the exercise cost of those options. Solely as a result of their ownership interest in the general partners of the general partners of the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the shares issued upon exercise of the stock options (i.e. no direct pecuniary interest).

4. As a result of their ownership interest in Baker Brothers Life Sciences Capital (GP), LLC, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in 10,000 shares of Common Stock of the Issuer received upon the exercise of stock options of the Issuer held by Baker Brothers Life Sciences, L.P. ("Life Sciences"), a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences. The policy of the Funds (defined below) and the Adviser (defined below), does not permit employees or principals of the Adviser to receive compensation for serving as Directors of the Issuer. The shares of common stock were received upon exercise of 10,000 stock options that were issued to Felix J. Baker in his capacity as a director of the Issuer. Felix J. Baker, pursuant to the policies of the Adviser, does not have any right to the pecuniary interest in the stock options issued for his service on the Board or the shares of common stock received upon exercise of such stock options. Each of the Funds owns an indirect proportionate pecuniary interest in the shares of common stock received upon exercise of the stock options issued in connection with Felix J. Baker's service on the Board less the exercise cost of those options. Solely as a result of their ownership interest in the general partners of the general partners of the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the shares issued upon exercise of the stock options (i.e. no direct pecuniary interest).

5. As a result of their ownership interest in 14159 Capital (GP), LLC, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in 10,000 shares of Common Stock of the Issuer received upon the exercise of stock options of the Issuer held by 14159, L.P. ("14159"), a limited partnership of which the sole general partner is 14159 Capital, L.P., a limited partnership of which the sole general partner is 14159 Capital (GP), LLC, due to 14159 Capital, L.P.'s right to receive an allocation of a portion of the profits from 14159. The policy of the Funds (defined below) and the Adviser (defined below), does not permit employees or principals of the Adviser to receive compensation for serving as Directors of the Issuer. The shares of common stock were received upon exercise of 10,000 stock options that were issued to Felix J. Baker in his capacity as a director of the Issuer. Felix J. Baker, pursuant to the policies of the Adviser, does not have any right to the pecuniary interest in the stock options issued for his service on the Board or the shares of common stock received upon exercise of such stock options. Each of the Funds owns an indirect proportionate pecuniary interest in the shares of common stock received upon exercise of the stock options issued in connection with Felix J. Baker's service on the Board less the exercise cost of those options. Solely as a result of their ownership interest in the general partners of the general partners of the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the shares issued upon exercise of the stock options (i.e. no direct pecuniary interest).

6. Baker Bros. Advisors LP (the "Adviser") serves as the Investment Adviser to the Funds (defined below). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held by the Funds. Baker Bros. Advisors (GP) LLC (the Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are principals of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held by the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held by the Funds. Pursuant to agreements between Felix J. Baker and the Adviser, the Adviser has investment and dispositive power over the stock options and any shares received as a result of the exercise of options. Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

7. The price reported in Column 4 is a weighted average price. These shares were purchased by Life Sciences and 14159 in multiple transactions all at a price of $34.10. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

8. After giving effect to the transactions reported herein and as a result of their ownership interest in Baker Brothers Life Sciences Capital (GP), LLC, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in the Issuer's shares of Common Stock reported in column 5 of Table I directly held by Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

9. After giving effect to the transactions reported herein and as a result of their ownership interest in 14159 Capital (GP), LLC, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in the Issuer's shares of Common Stock reported in Column 5 of Table I directly held by 14159, and together with 667 and Life Sciences, the "Funds"), a limited partnership of which the sole general partner is 14159 Capital L.P., a limited partnership of which the sole general partner is 14159 Capital (GP), LLC, due to 14159 Capital L.P.'s right to receive an allocation of a portion of the profits from 14159.

10. The price reported in Column 4 is a weighted average price. These shares were purchased by Life Sciences and 14159 in multiple transactions at prices ranging from $34.11 to $34.49, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

11. Restricted Stock Units (the "Restricted Stock Units") payable solely in Common Shares granted to Felix J. Baker on May 16, 2014, pursuant to the Amended and Restated 2007 Equity Incentive Plan. The Restricted Stock Units fully vest on May 15, 2015. Felix J. Baker serves on the Issuer's Board of Directors (the "Board") as a representative of the Funds (as defined below). Pursuant to the policies of Baker Bros. Advisors LP (the "Adviser"), Felix J. Baker did not have a right to any of the Issuer's securities issued as part of his service on the Board and the Funds (as defined below), were entitled to receive all the pecuniary interest in the securities issued. 667, Life Sciences and 14159(collectively the "Funds") each owns an indirect proportionate pecuniary interest in the Restricted Stock Units. Solely as a result of Julian C. Baker's and Felix J. Baker's ownership interest in the general partners of the general partners of the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the Restricted Stock Units (i.e., no direct pecuniary interest).

12. After giving effect to the transactions reported herein and as a result of their ownership interest in Baker Biotech Capital (GP), LLC, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in the Issuer's shares of Common Stock reported in column 5 of Table I directly held by 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

13. Non-qualified stock options ("Stock Options") convertible solely into Common Shares granted to Felix J. Baker on May 16, 2014, pursuant to the Issuer's Amended and Restated 2007 Equity Incentive Plan. The Stock Options with a strike price of $34.25 vest on May 15, 2015. Felix J. Baker serves on the Board as a representative of the Funds. Pursuant to the policies of the Adviser, Felix J. Baker did not have a right to any of the Issuer's securities issued as part of his service on the Board and the Funds, were entitled to receive all the pecuniary interest in the securities issued. The Funds each own an indirect proportionate pecuniary interest in the Stock Options. Solely as a result of Felix J. Baker's and Julian C. Baker's ownership interest in the general partners of the general partners of the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the Stock Options (i.e. no direct pecuniary interest).

14. As a result of their ownership interest in Baker Biotech Capital (GP), LLC, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in 8,750 options to purchase the Common Stock of the Issuer beneficially owned by 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

15. As a result of their ownership interest in Baker Brothers Life Sciences Capital (GP), LLC, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest 8,750 options to purchase Common Stock of the Issuer beneficially owned by Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

16. As a result of their ownership interest in 14159 Capital (GP), LLC, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in 8,750 options to purchase Common Stock of the Issuer beneficially owned by 14159, a limited partnership of which the sole general partner is 14159 Capital L.P., a limited partnership of which the sole general partner is 14159 Capital (GP), LLC, due to 14159 Capital L.P.'s right to receive an allocation of a portion of the profits from 14159.

17. The aggregate indirect beneficial ownership reported on this form is 21,464,919 shares (not including any shares underlying options included in Table II).

18. The price reported in Column 4 is a weighted average price. These shares were purchased by Life Sciences and 14159 in multiple transactions at prices ranging from $33.60 to $34.42, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

19. The price reported in Column 4 is a weighted average price. These shares were purchased by Life Sciences and 14159 in multiple transactions at prices ranging from $34.00 to $34.20, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

Remarks:

Felix J. Baker is a director of Seattle Genetics, Inc. (the "Issuer"). By virtue of his representation on the Board of Directors of the Issuer, for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, the reporting persons are deemed directors by deputization of the Issuer.

	/s/ Felix J. Baker	05/16/2014
	/s/ Julian C. Baker	05/16/2014
	By: Baker Bros. Advisors (GP) LLC, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing	05/16/2014
	By: Baker Bros. Advisors LP, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing	05/16/2014
	Baker Bros. Advisors LP, Mgmt. Co. and Inv. Adviser to 667, L.P., pursuant to authority granted by Baker Biotech Capital, L.P., GP to 667, L.P. Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing	05/16/2014
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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