Form 4 - Statement of changes in beneficial ownership of securities

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	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
X	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
	Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person* BAKER BROS. ADVISORS LP (Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR (Street) NEW YORK NY 10014 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol Seagen Inc. [ SGEN ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner Officer (give title below) X Other (specify below) Former 10% Owner
	3. Date of Earliest Transaction (Month/Day/Year) 12/14/2023
	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)
			Code	V	Amount	(A) or (D)	Price
Common Stock	12/14/2023		D(1)		23,280(1)	D	$229(1)(2)	0(3)	D
Common Stock	12/14/2023		D(1)		23,277(1)	D	$229(1)(2)	0(4)	D
Common Stock	12/14/2023		D(1)		1,731,202(1)	D	$229(1)(2)(5)(6)	0	I	See Footnotes(7)(8)(9)(10)(11)(12)
Common Stock	12/14/2023		D(1)		42,977,301(1)	D	$229(1)(2)(5)(6)	0	I	See Footnotes(8)(9)(10)(11)(12)(13)

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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Options (right to buy)	$34.25	12/14/2023		D(1)			8,750	(14)	05/16/2024	Common Stock	8,750	(14)	0	I	See Footnotes(8)(9)(10)(11)
Stock Options (right to buy)	$39.94	12/14/2023		D(1)			9,260	(14)	05/15/2025	Common Stock	9,260	(14)	0	I	See Footnotes(8)(9)(10)(11)
Stock Options (right to buy)	$38.82	12/14/2023		D(1)			9,260	(14)	05/20/2026	Common Stock	9,260	(14)	0	I	See Footnotes(8)(9)(10)(11)
Stock Options (right to buy)	$66.6	12/14/2023		D(1)			9,260	(14)	05/19/2027	Common Stock	9,260	(14)	0	I	See Footnotes(8)(9)(10)(11)
Stock Options (right to buy)	$56.77	12/14/2023		D(1)			9,260	(14)	05/18/2028	Common Stock	9,260	(14)	0	I	See Footnotes(8)(9)(10)(11)
Stock Options (right to buy)	$64.38	12/14/2023		D(1)			7,038	(14)	05/20/2029	Common Stock	7,038	(14)	0	I	See Footnotes(8)(9)(10)(11)
Stock Options (right to buy)	$160.33	12/14/2023		D(1)			3,371	(14)	05/15/2030	Common Stock	3,371	(14)	0	I	See Footnotes(8)(9)(10)(11)
Stock Options (right to buy)	$147.5	12/14/2023		D(1)			3,462	(14)	05/14/2031	Common Stock	3,462	(14)	0	I	See Footnotes(8)(9)(10)(11)
Stock Options (right to buy)	$135.63	12/14/2023		D(1)			3,676	(14)	05/13/2032	Common Stock	3,676	(14)	0	I	See Footnotes(8)(9)(10)(11)

1. Name and Address of Reporting Person* BAKER BROS. ADVISORS LP (Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR (Street) NEW YORK NY 10014 (City) (State) (Zip)

1. Name and Address of Reporting Person* 667, L.P. (Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR (Street) NEW YORK NY 10014 (City) (State) (Zip)

1. Name and Address of Reporting Person* BAKER JULIAN (Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR (Street) NEW YORK NY 10014 (City) (State) (Zip)

1. Name and Address of Reporting Person* BAKER FELIX (Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR (Street) NEW YORK NY 10014 (City) (State) (Zip)

1. Name and Address of Reporting Person* Baker Bros. Advisors (GP) LLC (Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR (Street) NEW YORK NY 10014 (City) (State) (Zip)

1. Name and Address of Reporting Person* Baker Brothers Life Sciences LP (Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR (Street) NEW YORK NY 10014 (City) (State) (Zip)

Explanation of Responses:

1. Reflects the disposition of shares of common stock ("Common Stock"), of Seagen Inc. (the "Issuer"), or of options to purchase Common Stock ("Stock Options"), as applicable, in connection with the consummation of the transactions contemplated by the Agreement and Plan of Merger, dated as of March 12, 2023 (the "Merger Agreement"), by and among the Issuer, Pfizer Inc. ("Parent") and Aris Merger Sub, Inc. ("Merger Sub"), a wholly owned subsidiary of Parent, pursuant to which, at the effective time of the Merger on December 14, 2023 (the "Effective Time"), Merger Sub merged with and into the Issuer, with the Issuer surviving as a subsidiary of Parent (the "Merger").

2. Pursuant to the Merger Agreement, at the Effective Time, each issued and outstanding share of Common Stock (other than certain excluded shares described in the Merger Agreement) was converted into the right to receive cash in an amount equal to $229.00 per share of Common Stock (the "Merger Consideration").

3. Reflects shares of Common Stock held directly by Felix J. Baker.

4. Reflects shares of Common Stock held directly by Julian C. Baker.

5. Pursuant to the Merger Agreement, at the Effective Time, 29,003 vested restricted stock units (each, an "RSU"), held by Felix J. Baker were converted into the right to receive an amount in cash equal to the product of (i) the Merger Consideration, multiplied by (ii) the number of shares of Common Stock then subject to such RSU, net of applicable taxes and without interest.

6. Pursuant to the Merger Agreement, at the Effective Time, each of the 2,044 RSUs granted to Felix J. Baker on May 31, 2023 that were unvested as of immediately prior to the Effective Time (each, a "Post-Signing Company RSU") were converted into the right to receive a Parent cash-based award subject to service-based vesting requirements with respect to an amount in cash equal to the product of (i) the Merger Consideration, multiplied by (ii) the number of shares of Common Stock then subject to such Post-Signing Company RSU.

7. As a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may have been deemed to have had an indirect pecuniary interest in Common Stock 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 their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

8. Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). 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 managing members 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.

9. Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities that were 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 was a beneficial owner of such securities for purposes of Section 16 or any other purpose.

10. Pursuant to agreements between Felix J. Baker and the Adviser, the Adviser had voting and dispositive power over Stock Options, RSUs and any Common Stock received as a result of the exercise of Stock Options or vesting of RSUs.

11. Pursuant to the policies of the Adviser, Felix J. Baker does not have a right to any of the Issuer's securities issued in lieu of director retainer fees and the Funds are entitled to an indirect proportionate pecuniary interest in such securities. The Funds each owned an indirect proportionate pecuniary interest in the shares of Common Stock. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may have been deemed to have had an indirect pecuniary interest in the shares of Common Stock issued in lieu of director retainer fees, Stock Options, Common Stock issued upon exercise of Stock Options, RSUs and Common Stock received upon vesting of RSUs (ie. no direct pecuniary interest).

12. Includes beneficial ownership of 31,047 previously issued RSUs payable solely in Common Stock issued to Felix Baker in his capacity as a director of the Issuer pursuant to the Amended and Restated 2007 Equity Incentive Plan of which the Funds may be deemed to own a portion and 121,250 previously issued shares of Common Stock from exercise of 121,250 Stock Options of the Issuer that were issued to Felix J. Baker in his capacity as a director of the Issuer, of which the Funds may be deemed to own a portion. The policy of the Funds and the Adviser does not permit full-time employees of the Adviser or managing members of the Adviser GP to receive compensation for serving as a director of the Issuer.

13. As a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may have been deemed to have had an indirect pecuniary interest in Common Stock 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 their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

14. Pursuant to the Merger Agreement, each outstanding Stock Option, whether or not then vested, was cancelled in exchange for the right to receive an amount in cash equal to the product of (i) the excess, if any, of the Merger Consideration over the per-share exercise price of such option, multiplied by (ii) the number of shares of Common Stock then subject to such Stock Option.

Remarks:

Felix J. Baker was a director of Seagen Inc. (the "Issuer"). By virtue of their 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 other than Felix J. Baker were deemed directors by deputization of the Issuer.

	By: Baker Bros. Advisors LP, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing	12/18/2023
	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	12/18/2023
	/s/ Julian C. Baker	12/18/2023
	/s/ Felix J. Baker	12/18/2023
	By: Baker Bros. Advisors (GP) LLC, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing	12/18/2023
	Baker Bros. Advisors LP, Mgmt. Co. and Inv. Adviser to Baker Brothers Life Sciences, L.P., pursuant to authority granted by Baker Brothers Life Sciences Capital, L.P., GP to Baker Brothers Life Sciences, L.P., Name: Scott L. Lessing, Title: President /s/	12/18/2023
	** Signature of Reporting Person	Date
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* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
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