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
	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* TAKEDA PHARMACEUTICAL CO LTD (Last) (First) (Middle) 1-1, NIHONBASHI-HONCHO 2-CHOME (Street) CHUO-KU, TOKYO M0 103-8668 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol Day One Biopharmaceuticals, Inc. [ DAWN ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 12/03/2021
	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	12/03/2021		S		12,517	D	$18.47(1)	6,515,089	I	See Explanation of Responses(2)(3)(4)
Common Stock	12/06/2021		S		97,692	D	$18.05(5)	6,417,397	I	See Explanation of Responses(2)(3)(4)

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

1. Name and Address of Reporting Person* TAKEDA PHARMACEUTICAL CO LTD (Last) (First) (Middle) 1-1, NIHONBASHI-HONCHO 2-CHOME (Street) CHUO-KU, TOKYO M0 103-8668 (City) (State) (Zip)

1. Name and Address of Reporting Person* Takeda Pharmaceuticals U.S.A., Inc. (Last) (First) (Middle) 95 HAYDEN AVENUE (Street) LEXINGTON MA 02421 (City) (State) (Zip)

1. Name and Address of Reporting Person* MILLENNIUM PHARMACEUTICALS INC (Last) (First) (Middle) 40 LANDSDOWNE STREET (Street) CAMBRIDGE MA 02139 (City) (State) (Zip)

1. Name and Address of Reporting Person* Takeda Ventures, Inc. (Last) (First) (Middle) 9625 TOWNE CENTRE DRIVE (Street) SAN DIEGO CA 92121 (City) (State) (Zip)

Explanation of Responses:

1. Reflects the weighted average sale price. This transaction was executed in multiple trades at prices ranging from $18.10 to $18.78. Information regarding the number of shares sold at each separate price will be provided upon request by the Staff of the Securities and Exchange Commission, the Issuer or any security holder of the Issuer.

2. This statement is being filed jointly by Takeda Pharmaceutical Company Limited, Takeda Pharmaceuticals U.S.A. Inc., Millennium Pharmaceuticals, Inc. and Takeda Ventures, Inc.

3. Takeda Pharmaceutical Company Limiteds beneficial ownership of the reported securities is comprised of 6,360,173 shares of Common Stock held by Millennium Pharmaceuticals, Inc. and 57,224 shares of Common Stock held by Takeda Ventures, Inc. Millennium Pharmaceuticals, Inc. and Takeda Ventures, Inc. are each direct, wholly owned subsidiaries of Takeda Pharmaceuticals U.S.A. Inc., which is a direct subsidiary of Takeda Pharmaceutical Company Limited (72.70%) and Takeda Pharmaceuticals International AG (27.3%).

4. Takeda Pharmaceuticals International AG is a direct, wholly owned subsidiary of Takeda Pharmaceutical Company Limited. Each of Takeda Pharmaceutical Company Limited and Takeda Pharmaceuticals U.S.A. Inc. may be deemed to share voting and dispositive power over the shares held by Takeda Ventures, Inc. and Millennium Pharmaceuticals, Inc. Each of Takeda Pharmaceutical Company Limited and Takeda Pharmaceuticals U.S.A. Inc. disclaims beneficial ownership of the shares held by Takeda Ventures, Inc. and Millennium Pharmaceuticals, Inc. except to the extent of their pecuniary interests therein.

5. Reflects the weighted average sale price. This transaction was executed in multiple trades at prices ranging from $18.00 to $18.27. Information regarding the number of shares sold at each separate price will be provided upon request by the Staff of the Securities and Exchange Commission, the Issuer or any security holder of the Issuer.

Remarks:

	/s/ Yoshihiro Nakagawa, Corporate Officer, Global General Counsel of Takeda Pharmaceutical Company Limited	12/07/2021
	/s/ Paul Sundberg, Assistant Secretary of Takeda Pharmaceuticals U.S.A., Inc.	12/07/2021
	/s/ Paul Sundberg, Attorney-in-Fact for Millennium Pharmaceuticals, Inc.	12/07/2021
	/s/ Michael Martin, President of Takeda Ventures, Inc.	12/07/2021
	** Signature of Reporting Person	Date
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