SEC Form 3

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* AI Day 1 LLC (Last) (First) (Middle) C/O ACCESS INDUSTRIES, INC. 40 WEST 57TH STREET, 28TH FLOOR (Street) NEW YORK NY 10019 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 05/26/2021	3. Issuer Name and Ticker or Trading Symbol Day One Biopharmaceuticals, Inc. [ DAWN ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 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) Form filed by One Reporting Person X 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
Series A Redeemable Convertible Preferred Stock	(1)	(1)	Common Stock	7,761,380	(1)	D(2)
Series B Redeemable Convertible Preferred Stock	(3)	(3)	Common Stock	741,396	(3)	D(2)

1. Name and Address of Reporting Person* AI Day 1 LLC (Last) (First) (Middle) C/O ACCESS INDUSTRIES, INC. 40 WEST 57TH STREET, 28TH FLOOR (Street) NEW YORK NY 10019 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Access Industries Holdings LLC (Last) (First) (Middle) C/O ACCESS INDUSTRIES, INC. 40 WEST 57TH STREET, 28TH FL (Street) NEW YORK NY 10019 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Affiliate of 10% Owner

1. Name and Address of Reporting Person* ACCESS INDUSTRIES MANAGEMENT, LLC (Last) (First) (Middle) C/O ACCESS INDUSTRIES, INC. 40 WEST 57TH STREET, 28TH FLOOR (Street) NEW YORK NY 10019 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Affiliate of 10% Owner

1. Name and Address of Reporting Person* Blavatnik Len (Last) (First) (Middle) C/O ACCESS INDUSTRIES, INC. 40 WEST 57TH STREET, 28TH FL (Street) NEW YORK NY 10019 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Affiliate of 10% Owner

Explanation of Responses:

1. Each outstanding share of Series A Redeemable Convertible Preferred Stock will each automatically convert into one share of common stock of Day One Biopharmaceuticals, Inc. (the "Issuer") immediately prior to the completion of the Issuer's initial public offering and has no expiration date.

2. The securities reported are held directly by AI Day 1 LLC and may be deemed to be beneficially owned by Access Industries Holdings LLC ("AIH"), Access Industries Management, LLC ("AIM") and Len Blavatnik because AIH indirectly controls all of the outstanding voting interests in AI Day 1 LLC, AIM controls AIH and Mr. Blavatnik controls AIM and holds a majority of the outstanding voting interests in AIH. AIH, AIM and Mr. Blavatnik each disclaims beneficial ownership of these securities, except to the extent of its or his pecuniary interest therein, and this form shall not be construed as an admission that any such reporting person is the beneficial owner of any of the securities reported on this form.

3. Each outstanding share of Series B Redeemable Convertible Preferred Stock will each automatically convert into one share of common stock of the Issuer immediately prior to the completion of the Issuer's initial public offering and has no expiration date.

Remarks:

Exhibit List: Ex.24 - Power of Attorney

	/s/ Alejandro Moreno for AI Day 1 LLC	05/26/2021
	/s/ Alejandro Moreno for Access Industries Holdings LLC	05/26/2021
	/s/ Alejandro Moreno for Access Industries Management, LLC	05/26/2021
	/s/ Alejandro Moreno as Attorney-in-Fact for Mr. Blavatnik	05/26/2021
	** Signature of Reporting Person	Date
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