<SEC-DOCUMENT>0000950170-24-115295.txt : 20241017
<SEC-HEADER>0000950170-24-115295.hdr.sgml : 20241017
<ACCEPTANCE-DATETIME>20241017160504
ACCESSION NUMBER:		0000950170-24-115295
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20241015
FILED AS OF DATE:		20241017
DATE AS OF CHANGE:		20241017

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Blavatnik Len
		CENTRAL INDEX KEY:			0001326628
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-42366
		FILM NUMBER:		241377626

	MAIL ADDRESS:	
		STREET 1:		C/O ACCESS INDUSTRIES
		STREET 2:		730 FIFTH AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Access Industries Holdings LLC
		CENTRAL INDEX KEY:			0001391297
		ORGANIZATION NAME:           	
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-42366
		FILM NUMBER:		241377628

	BUSINESS ADDRESS:	
		STREET 1:		C/O ACCESS INDUSTRIES MANAGEMENT, LLC.
		STREET 2:		730 FIFTH AVENUE, 20TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019
		BUSINESS PHONE:		212 247 6400

	MAIL ADDRESS:	
		STREET 1:		C/O ACCESS INDUSTRIES MANAGEMENT, LLC.
		STREET 2:		730 FIFTH AVENUE, 20TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			AI Upstream LLC
		CENTRAL INDEX KEY:			0002039907
		ORGANIZATION NAME:           	
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-42366
		FILM NUMBER:		241377630

	BUSINESS ADDRESS:	
		STREET 1:		ACCESS INDUSTRIES MANAGEMENT LLC
		STREET 2:		40 WEST 57TH STREET, 28TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019
		BUSINESS PHONE:		212-247-6400

	MAIL ADDRESS:	
		STREET 1:		ACCESS INDUSTRIES MANAGEMENT LLC
		STREET 2:		40 WEST 57TH STREET, 28TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			AI Biotechnology LLC
		CENTRAL INDEX KEY:			0001942670
		ORGANIZATION NAME:           	
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-42366
		FILM NUMBER:		241377629

	BUSINESS ADDRESS:	
		STREET 1:		C/O ACCESS INDUSTRIES, INC.
		STREET 2:		40 WEST 57TH STREET, 28TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019
		BUSINESS PHONE:		212-247-6400

	MAIL ADDRESS:	
		STREET 1:		C/O ACCESS INDUSTRIES, INC.
		STREET 2:		40 WEST 57TH STREET, 28TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ACCESS INDUSTRIES MANAGEMENT, LLC
		CENTRAL INDEX KEY:			0001508226
		ORGANIZATION NAME:           	
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-42366
		FILM NUMBER:		241377627

	BUSINESS ADDRESS:	
		STREET 1:		730 FIFTH AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019
		BUSINESS PHONE:		2122476400

	MAIL ADDRESS:	
		STREET 1:		730 FIFTH AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Upstream Bio, Inc.
		CENTRAL INDEX KEY:			0002022626
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		890 WINTER STREET, SUITE 200
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451
		BUSINESS PHONE:		781-208-2466

	MAIL ADDRESS:	
		STREET 1:		890 WINTER STREET, SUITE 200
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451
</SEC-HEADER>
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            <rptOwnerCity>NEW YORK</rptOwnerCity>
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            <rptOwnerName>ACCESS INDUSTRIES MANAGEMENT, LLC</rptOwnerName>
        </reportingOwnerId>
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            <rptOwnerStreet2>40 WEST 57TH STREET, 28TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
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    <reportingOwner>
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            <rptOwnerCik>0001326628</rptOwnerCik>
            <rptOwnerName>Blavatnik Len</rptOwnerName>
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            <rptOwnerStreet2>40 WEST 57TH STREET, 28TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
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            <isOther>false</isOther>
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    </reportingOwner>

    <aff10b5One>true</aff10b5One>

    <nonDerivativeTable>
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                <value>Common Stock</value>
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            <transactionDate>
                <value>2024-10-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>1175000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>17.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
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                </transactionAcquiredDisposedCode>
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        </nonDerivativeTransaction>
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    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Series A Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
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                <value>2024-10-15</value>
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            <securityTitle>
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    <footnotes>
        <footnote id="F1">Each share of the Issuer's Series A preferred stock and Series B preferred stock (collectively, the &quot;Preferred Stock&quot;) 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.</footnote>
        <footnote id="F2">The securities reported are held directly by AI Upstream LLC (&quot;AI Upstream&quot;) and may be deemed to be beneficially owned by AI Biotechnology LLC (&quot;AI Biotechnology&quot;), Access Industries Holdings LLC (&quot;AIH&quot;), Access Industries Management, LLC (&quot;AIM&quot;) 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.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Alejandro Moreno for AI Upstream LLC</signatureName>
        <signatureDate>2024-10-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Alejandro Moreno for AI Biotechnology LLC</signatureName>
        <signatureDate>2024-10-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Alejandro Moreno for Access Industries Holdings LLC</signatureName>
        <signatureDate>2024-10-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Alejandro Moreno for Access Industries Management, LLC</signatureName>
        <signatureDate>2024-10-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Alejandro Moreno as Attorney-in-Fact for Mr. Blavatnik</signatureName>
        <signatureDate>2024-10-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</SEC-DOCUMENT>
