Access Industries Management Form 4 Upstream Bio / Len Blavatnik ownership change

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^*

AI Upstream LLC

(Last) (First) (Middle)

C/O ACCESS INDUSTRIES, INC.

40 WEST 57TH STREET, 28TH FLOOR

(Street)

NEW YORK NY 10019

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Upstream Bio, Inc. [ UPB ]

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)
10/15/2024

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	10/15/2024		P		1,175,000	A	$17	1,175,000	D(2)
Common Stock	10/15/2024		C		3,147,000	A	(1)	4,322,000	D(2)
Common Stock	10/15/2024		C		1,172,410	A	(1)	5,494,410	D(2)

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
Series A Convertible Preferred Stock	(1)	10/15/2024		C			3,147,000	(1)	(1)	Common Stock	3,147,000	(1)	0	D(2)
Series B Convertible Preferred Stock	(1)	10/15/2024		C			1,172,410	(1)	(1)	Common Stock	1,172,410	(1)	0	D(2)

1. Name and Address of Reporting Person^*

AI Upstream LLC

(Last) (First) (Middle)

C/O ACCESS INDUSTRIES, INC.

40 WEST 57TH STREET, 28TH FLOOR

(Street)

NEW YORK NY 10019

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

AI Biotechnology LLC

(Last) (First) (Middle)

C/O ACCESS INDUSTRIES, INC.

40 WEST 57TH STREET, 28TH FLOOR

(Street)

NEW YORK NY 10019

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Access Industries Holdings LLC

(Last) (First) (Middle)

C/O ACCESS INDUSTRIES, INC.

40 WEST 57TH STREET, 28TH FLOOR

(Street)

NEW YORK NY 10019

(City) (State) (Zip)

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)

1. Name and Address of Reporting Person^*

Blavatnik Len

(Last) (First) (Middle)

C/O ACCESS INDUSTRIES, INC.

40 WEST 57TH STREET, 28TH FLOOR

(Street)

NEW YORK NY 10019

(City) (State) (Zip)

Explanation of Responses:

1. Each share of the Issuer's Series A preferred stock and Series B preferred stock (collectively, the "Preferred Stock") converted into Common Stock on a 1.049-for-one basis upon closing of the Issuer's initial public offering without payment of consideration. The Preferred Stock had no expiration date.

2. The securities reported are held directly by AI Upstream LLC ("AI Upstream") and may be deemed to be beneficially owned by AI Biotechnology LLC ("AI Biotechnology"), Access Industries Holdings LLC ("AIH"), Access Industries Management, LLC ("AIM") and Len Blavatnik because (i) Mr. Blavatnik controls AIM and AIH, (ii) AIM controls AIH, (iii) AIH owns all of the voting units of AI Biotechnology and (iv) AI Biotechnology owns all of the voting units of AI Upstream. Each of the reporting persons (other than AI Upstream) 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.

	/s/ Alejandro Moreno for AI Upstream LLC	10/17/2024
	/s/ Alejandro Moreno for AI Biotechnology LLC	10/17/2024
	/s/ Alejandro Moreno for Access Industries Holdings LLC	10/17/2024
	/s/ Alejandro Moreno for Access Industries Management, LLC	10/17/2024
	/s/ Alejandro Moreno as Attorney-in-Fact for Mr. Blavatnik	10/17/2024
	** Signature of Reporting Person	Date
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