UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

 

SCHEDULE 13D

Under the Securities Exchange Act of 1934

 

(Amendment No. 8)

 

Seattle Genetics, Inc

(Name of Issuer)

 

Common Stock, par value $0.001 per share

(Title of Class of Securities)

 

	812578102
	(CUSIP Number)

 

Leo Kirby 667 Madison Avenue, 21st Floor New York, NY  10065 (212) 339-5633

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

 

	December 12, 2013
	(Date of Event which Requires Filing of this Statement)

 

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following box. ¨

 

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent.

 

*The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

 

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (the “Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

 

 

SCHEDULE 13D

 

CUSIP No.    812578102

Page   2   of   12   Pages

 

1	NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS   Baker Bros. Advisors LP   13-4093645
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions)	(a) ¨   (b) ¨
3	SEC USE ONLY
4	SOURCE OF FUNDS (See Instructions)   OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e)	¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION   Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER   20,735,926
	8	SHARED VOTING POWER   0
	9	SOLE DISPOSITIVE POWER   20,735,926
	10	SHARED DISPOSITIVE POWER   0

11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON   20,735,926
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions)	¨
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)   16.9%(1)
14	TYPE OF REPORTING PERSON (See Instructions)   IA

(1) Based on 122,481,320 shares of the Issuer’s common stock outstanding as of November 5, 2013, as reported in the Issuer’s quarterly report on Form 10-Q filed with the SEC on November 8, 2013.

 

 

SCHEDULE 13D

 

CUSIP No.    812578102

Page   3   of   12   Pages

 

1	NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS   Baker Bros. Advisors (GP) LLC   46-37147749
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions)	(a) ¨   (b) ¨
3	SEC USE ONLY
4	SOURCE OF FUNDS (See Instructions)   OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e)	¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION   Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER   20,735,926
	8	SHARED VOTING POWER   0
	9	SOLE DISPOSITIVE POWER   20,735,926
	10	SHARED DISPOSITIVE POWER   0

11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON   20,735,926
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions)	¨
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)   16.9%(1)
14	TYPE OF REPORTING PERSON (See Instructions)   IA

(1) Based on 122,481,320 shares of the Issuer’s common stock outstanding as of November 5, 2013, as reported in the Issuer’s quarterly report on Form 10-Q filed with the SEC on November 8, 2013.

SCHEDULE 13D

 

CUSIP No.    812578102

Page   4   of   12   Pages

 

1	NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS   Julian C. Baker
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions)	(a) ¨   (b) ¨
3	SEC USE ONLY
4	SOURCE OF FUNDS (See Instructions)   OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e)	¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION   United States

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER   20,831,166
	8	SHARED VOTING POWER   0
	9	SOLE DISPOSITIVE POWER   20,831,166
	10	SHARED DISPOSITIVE POWER   0

11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON   20,831,166
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions)	¨
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)   17.0%(1)
14	TYPE OF REPORTING PERSON (See Instructions)   IN, HC

(1) Based on 122,481,320 shares of the Issuer’s common stock outstanding as of November 5, 2013, as reported in the Issuer’s quarterly report on Form 10-Q filed with the SEC on November 8, 2013.

 

 

SCHEDULE 13D

 

CUSIP No.  812578102

Page   5   of   12    Pages

 

1	NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS   Felix J. Baker
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions)	(a) ¨ (b) ¨
3	SEC USE ONLY
4	SOURCE OF FUNDS (See Instructions)   OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e)	¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION   United States

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER   20,943,673(1)
	8	SHARED VOTING POWER   0
	9	SOLE DISPOSITIVE POWER   20,943,673(1)
	10	SHARED DISPOSITIVE POWER   0

11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON   20,943,673(1)
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions)	¨
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)   17.1%(2)
14	TYPE OF REPORTING PERSON (See Instructions)   IN, HC

(1) Includes 112,500 shares of the Issuer’s common stock underlying 112,500 options directly held.

(2) Based on 122,481,320 shares of the Issuer’s common stock outstanding as of November 5, 2013, as reported in the Issuer’s quarterly report on Form 10-Q filed with the SEC on November 8, 2013.

 

 

SCHEDULE 13D

 

CUSIP No.  812578102

Page   6   of   12    Pages

 

1	NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS   FBB2, LLC   45-5474130
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions)	(a) ¨ (b) ¨
3	SEC USE ONLY
4	SOURCE OF FUNDS (See Instructions)   OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e)	¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION   Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER   18,243
	8	SHARED VOTING POWER   0
	9	SOLE DISPOSITIVE POWER   18,243
	10	SHARED DISPOSITIVE POWER   0

11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON   18,243
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions)	¨
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)   (1)
14	TYPE OF REPORTING PERSON (See Instructions)   OO

(1) The percentage of ownership is less than 0.1%. (2) Based on 122,481,320 shares of the Issuer’s common stock outstanding as of November 5, 2013, as reported in the Issuer’s quarterly report on Form 10-Q filed with the SEC on November 8, 2013.

 

 

Amendment No. 8 to Schedule 13D

 

This Amendment No. 8 to Schedule 13D amends and supplements the statements on the previously filed Schedules 13D filed by Baker Bros. Advisors LP (the “Adviser”), Baker Bros. Advisors (GP) LLC (the “Adviser GP”), Julian C. Baker, Felix J. Baker and FBB2, LLC (“FBB2”) (collectively the “Reporting Persons”). Except as supplemented herein, such statements, as heretofore amended and supplemented, remain in full force and effect.

 

The Adviser GP is the sole general partner of the Adviser. Pursuant to the amended and restated management agreements, as amended, among the Adviser, Baker Brothers Life Sciences, L.P. (“Life Sciences”), 14159, L.P. (“14159”), and 667, L.P. (“667”, and together with Life Sciences and 14159, the “Funds”), and their respective general partners, the Adviser has complete and unlimited discretion and authority with respect to the Funds’ investments and voting power over investments.

 

Item 5.

Interest in Securities of the Issuer.

 

(a) and (b) Items 7 through 11 and 13 of each of the cover pages of this Amendment No. 8 are incorporated herein by reference. Set forth below is the aggregate number and percentage of shares of Common Stock directly held, as of the date hereof, by each of the following based upon 122,481,320 shares outstanding as of November 5, 2013, as reported in the Issuer’s Form 10-Q filed with the SEC on November 8, 2013. Such percentage figures were calculated in accordance with Rule 13d-3 under the Securities Exchange Act of 1934 (the “Exchange Act”).

 

Reporting Person		Number of Shares				Percentage of Class Outstanding
667, L.P.			3,868,576				3.2	%
Baker Brothers Life Sciences, L.P.			16,509,798				13.5	%
14159, L.P.			357.552				0.3	%

 

The Adviser GP, Felix J. Baker and Julian C. Baker as principals of the Adviser GP, and the Adviser may be deemed to be beneficial owners of securities of the Issuer directly held by the Funds, and may be deemed to have the power to vote or direct the vote of and the power to dispose or direct the disposition of such securities.

 

The Reporting Persons disclaim beneficial ownership of the securities held by each of the Funds, and this Schedule 13D shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 13(d) or for any other purpose.

 

As discussed above, Julian C. Baker and Felix J. Baker are also the sole managers of FBB2 and as such may be deemed to be beneficial owners of shares owned by FBB2 and may be deemed to have the power to vote or direct the vote and dispose or direct the disposition of those shares.

 

Felix J. Baker is a Director of the Issuer.

 

 

(c) Felix J. Baker serves on the Issuer’s Board as representatives of the Funds. Due to the agreements and policies of the Funds, Felix J. Baker does not have any right to receive any profits from any securities as compensation for serving as a Director of the Issuer and therefore has no pecuniary interest in the restricted stock units payable solely in common shares of the Issuer (“Restricted Stock”) or in the options to purchase common stock of the Issuer (“Stock Options”). The Funds are entitled to the pecuniary interest in the Restricted Stock and Stock Options as each holds an indirect pecuniary interest. Felix J. Baker solely as a result of his ownership interest in the general partners of the general partners of the Funds may be deemed to have an indirect pecuniary interest in the Restricted Stock and Stock Options (ie. no direct pecuniary interest). Felix J. Baker currently retains voting and investment power over the shares of Restricted Stock and Stock Options.

 

The following transactions in the Issuer’s Common Stock were effected by the Funds noted below during the sixty days preceding the filing of this statement using working capital of the applicable purchasing Fund. All transactions were effected in the over-the-counter market directly with a broker-dealer. Except as disclosed herein or in any previous amendments to this Schedule 13D, none of the Reporting Persons or their affiliates has effected any other transactions in securities of the Issuer during the past 60 days.

 

Name		Date		Number of Shares				Transaction		Price/ Share				Footnotes
Baker Brothers Life Sciences, L.P.		12/3/2013			112,797			Purchase			42.3098				1
14159, L.P.		12/3/2013			2,816			Purchase			42.3098				1
Baker Brothers Life Sciences, L.P.		12/3/2013			105,414			Purchase			42.413				2
14159, L.P.		12/3/2013			2,632			Purchase			42.413				2
Baker Brothers Life Sciences, L.P.		12/3/2013			142,220			Purchase			42.5595				3
14159, L.P.		12/3/2013			3,551			Purchase			42.5595				3
Baker Brothers Life Sciences, L.P.		12/4/2013			11,617			Purchase			42.653				4
14159, L.P.		12/4/2013			290			Purchase			42.653				4
Baker Brothers Life Sciences, L.P.		12/4/2013			18,232			Purchase			42.645				5
14159, L.P.		12/4/2013			455			Purchase			42.645				5
Baker Brothers Life Sciences, L.P.		12/4/2013			72,807			Purchase			43.2049				6
14159, L.P.		12/4/2013			1,818			Purchase			43.2049				6
Baker Brothers Life Sciences, L.P.		12/4/2013			40,471			Purchase			43.0056				7
14159, L.P.		12/4/2013			1,011			Purchase			43.0056				7
Baker Brothers Life Sciences, L.P.		12/4/2013			13,632			Purchase			43.7189				8
14159, L.P.		12/4/2013			340			Purchase			43.7189				8
Baker Brothers Life Sciences, L.P.		12/4/2013			100,626			Purchase			42.9471				9
14159, L.P.		12/4/2013			2,512			Purchase			42.9471				9
Baker Brothers Life Sciences, L.P.		12/4/2013			6,814			Purchase			43.4247				10
14159, L.P.		12/4/2013			170			Purchase			43.4247				10
Baker Brothers Life Sciences, L.P.		12/5/2013			114,663			Purchase			44.0455				11
14159, L.P.		12/5/2013			2,863			Purchase			44.0455				11
Baker Brothers Life Sciences, L.P.		12/5/2013			22,147			Purchase			43.9995				12
14159, L.P.		12/5/2013			553			Purchase			43.9995				12
Baker Brothers Life Sciences, L.P.		12/5/2013			219,958			Purchase			43.9752				13
14159, L.P.		12/5/2013			5,492			Purchase			43.9752				13
Baker Brothers Life Sciences, L.P.		12/12/2013			122,660			Purchase			39.5283				14
14159, L.P.		12/12/2013			3,056			Purchase			39.5283				14
Baker Brothers Life Sciences, L.P.		12/12/2013			55,256			Purchase			39.537				15
14159, L.P.		12/12/2013			1,377			Purchase			39.537				15
Baker Brothers Life Sciences, L.P.		12/12/2013			99,775			Purchase			39.7				16
14159, L.P.		12/12/2013			2,486			Purchase			39.7				16
Baker Brothers Life Sciences, L.P.		12/13/2013			42,646			Purchase			39.6549				17
14159, L.P.		12/13/2013			1,063			Purchase			39.6549				17
Baker Brothers Life Sciences, L.P.		12/16/2013			51,244			Purchase			39.9219				18
14159, L.P.		12/16/2013			1,280			Purchase			39.9219				18
Baker Brothers Life Sciences, L.P.		12/16/2013			25,596			Purchase			39.9121				19
14159, L.P.		12/16/2013			639			Purchase			39.9121				19

 

 

(1) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $41.87 to $42.70. The Reporting Persons undertake to provide the staff of the Securities and Exchange Commission (the “Staff”), upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 (2) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $41.87 to $42.69 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 (3) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $42.39 to $42.66 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 (4) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $42.32 to $43.00 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 

 (5) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $43.55 to $43.70 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 (6) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $42.91 to $43.70 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 (7) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $42.69 to $43.65 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 (8) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $43.70 to $43.73 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 (9) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $42.34 to $43.30 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 (10) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $43.39 to $43.57 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 (11) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $43.50 to $44.29 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 (12) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $43.99 to $44.00 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 (13) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $43.61 to $44.30 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 (14) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $39.26 to $39.79 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 

 (15) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $39.40 to $39.65 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 (16) All of the shares traded in this transaction were traded in a single execution at the reported price of $39.70.

 

 (17) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $39.19 to $40.00 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 (18) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $39.77 to $40.00 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

 (19) The reported price is a weighted average price. These shares were traded in multiple transactions at prices ranging from $39.80 to $40.00 The Reporting Persons undertake to provide the Staff, upon request, full information regarding the number of shares traded at each separate price within the ranges set forth in this footnote.

 

(d) Certain securities of the Issuer are held directly by 667, a limited partnership the sole general partner of which is Baker Biotech Capital, L.P., a limited partnership the sole general partner of which is Baker Biotech Capital (GP), LLC. Julian C. Baker and Felix J. Baker are the controlling members of Baker Biotech Capital (GP), LLC.

 

Certain securities of the Issuer are held directly by Life Sciences, a limited partnership the sole general partner of which is Baker Brothers Life Sciences Capital, L.P., a limited partnership the sole general partner of which is Baker Brothers Life Sciences Capital (GP), LLC. Julian C. Baker and Felix J. Baker are the controlling members of Baker Brothers Life Sciences Capital (GP), LLC.

 

Certain securities of the Issuer are held directly by 14159, a limited partnership the sole general partner of which is 14159 Capital, L.P., a limited partnership the sole general partner of which is 14159 Capital (GP), LLC. Julian C. Baker and Felix J. Baker are the controlling members of 14159 Capital (GP), LLC.

 

(e) Not applicable.

 

Item 7.		Material to Be Filed as Exhibits.
Exhibit 99.1		Agreement regarding the joint filing of this statement.

 

 

SIGNATURE

 

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

 

December 16, 2013

 

	BAKER BROS. ADVISORS LP
	By:  Baker Bros. Advisors (GP) LLC, its general partner
	By:	/s/ Scott L. Lessing
		Name: Scott L. Lessing
		Title: President

 

	BAKER BROS. ADVISORS (GP) LLC
	By:	/s/ Scott L. Lessing
		Name: Scott L. Lessing Title: President

 

	/s/ Julian C. Baker
	Julian C. Baker
	/s/ Felix J. Baker
	Felix J. Baker

 

	FBB2, LLC
	By:	/s/ Julian C. Baker
		Name: Julian C. Baker
		Title: Manager