<SEC-DOCUMENT>0001415889-24-016256.txt : 20240610
<SEC-HEADER>0001415889-24-016256.hdr.sgml : 20240610
<ACCEPTANCE-DATETIME>20240610172639
ACCESSION NUMBER:		0001415889-24-016256
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20240610
FILED AS OF DATE:		20240610
DATE AS OF CHANGE:		20240610

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			RA Capital Healthcare Fund LP
		CENTRAL INDEX KEY:			0001315082
		ORGANIZATION NAME:           	
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-40551
		FILM NUMBER:		241033868

	BUSINESS ADDRESS:	
		STREET 1:		200 BERKELEY STREET
		STREET 2:		18TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
		BUSINESS PHONE:		6177782500

	MAIL ADDRESS:	
		STREET 1:		200 BERKELEY STREET
		STREET 2:		18TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116

	FORMER NAME:	
		FORMER CONFORMED NAME:	RA Capital Biotech Fund LP
		DATE OF NAME CHANGE:	20050121

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			RA CAPITAL MANAGEMENT, L.P.
		CENTRAL INDEX KEY:			0001346824
		ORGANIZATION NAME:           	
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-40551
		FILM NUMBER:		241033869

	BUSINESS ADDRESS:	
		STREET 1:		200 BERKELEY STREET, 18TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
		BUSINESS PHONE:		617-778-2500

	MAIL ADDRESS:	
		STREET 1:		200 BERKELEY STREET, 18TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116

	FORMER NAME:	
		FORMER CONFORMED NAME:	RA CAPITAL MANAGEMENT, LLC
		DATE OF NAME CHANGE:	20051213

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			RA Capital Nexus Fund II, L.P.
		CENTRAL INDEX KEY:			0001825376
		ORGANIZATION NAME:           	
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-40551
		FILM NUMBER:		241033867

	BUSINESS ADDRESS:	
		STREET 1:		200 BERKELEY STREET, 18TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
		BUSINESS PHONE:		617-778-2500

	MAIL ADDRESS:	
		STREET 1:		200 BERKELEY STREET, 18TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Kolchinsky Peter
		CENTRAL INDEX KEY:			0001384859
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-40551
		FILM NUMBER:		241033866

	MAIL ADDRESS:	
		STREET 1:		200 BERKELEY STREET
		STREET 2:		18TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Shah Rajeev M.
		CENTRAL INDEX KEY:			0001619841
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-40551
		FILM NUMBER:		241033865

	MAIL ADDRESS:	
		STREET 1:		200 BERKELEY STREET
		STREET 2:		18TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Acumen Pharmaceuticals, Inc.
		CENTRAL INDEX KEY:			0001576885
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		ORGANIZATION NAME:           	03 Life Sciences
		IRS NUMBER:				364108129
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		427 PARK ST.
		CITY:			CHARLOTTESVILLE
		STATE:			VA
		ZIP:			22902
		BUSINESS PHONE:		925-368-8508

	MAIL ADDRESS:	
		STREET 1:		427 PARK ST.
		CITY:			CHARLOTTESVILLE
		STATE:			VA
		ZIP:			22902
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4-06102024_090635.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-06-10</periodOfReport>

    <issuer>
        <issuerCik>0001576885</issuerCik>
        <issuerName>Acumen Pharmaceuticals, Inc.</issuerName>
        <issuerTradingSymbol>ABOS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001346824</rptOwnerCik>
            <rptOwnerName>RA CAPITAL MANAGEMENT, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>200 BERKELEY STREET, 18TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>true</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001315082</rptOwnerCik>
            <rptOwnerName>RA Capital Healthcare Fund LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>200 BERKELEY STREET, 18TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001825376</rptOwnerCik>
            <rptOwnerName>RA Capital Nexus Fund II, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>200 BERKELEY STREET, 18TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001384859</rptOwnerCik>
            <rptOwnerName>Kolchinsky Peter</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O RA CAPITAL MANAGEMENT, L.P.</rptOwnerStreet1>
            <rptOwnerStreet2>200 BERKELEY STREET, 18TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001619841</rptOwnerCik>
            <rptOwnerName>Shah Rajeev M.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O RA CAPITAL MANAGEMENT, L.P.</rptOwnerStreet1>
            <rptOwnerStreet2>200 BERKELEY STREET, 18TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>2.62</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-06-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>25000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2034-06-09</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>25000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnotes</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The shares subject to the option will vest on the earlier of June 10, 2025 or the 2025 annual stockholder meeting, subject to Ms. Stoppel's continuous service through each such vesting date.</footnote>
        <footnote id="F2">RA Capital Management, L.P. (the &quot;Adviser&quot;) is the investment manager for RA Capital Healthcare Fund, L.P. (the &quot;Fund&quot;), RA Capital Nexus Fund II, L.P. (the &quot;Nexus Fund II&quot;) and a separately managed account (the &quot;Account&quot;). The general partner of the Adviser is RA Capital Management GP, LLC (the
&quot;Adviser GP&quot;), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. The Adviser, the Adviser GP, the Fund, the Nexus Fund II, Dr. Kolchinsky, and Mr. Shah disclaim beneficial ownership of any of the reported securities, except to the extent of their pecuniary interest therein.</footnote>
        <footnote id="F3">Laura Stoppel is a Principal of the Adviser who serves on the Issuer's board of directors. Under Ms. Stoppel's arrangement with the Adviser, Ms. Stoppel holds the option for the benefit of the Fund and the Nexus Fund II. Ms. Stoppel is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option, which will offset advisory fees owed by the Fund and the Nexus Fund II to the Adviser. The Reporting Persons therefore disclaim beneficial ownership of the option and underlying common stock.</footnote>
    </footnotes>

    <remarks>Laura Stoppel, a Principal of the Adviser, serves on the Issuer's board of directors.</remarks>

    <ownerSignature>
        <signatureName>/s/ Peter Kolchinsky, Manager of RA Capital Management, L.P.</signatureName>
        <signatureDate>2024-06-10</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Peter Kolchinsky, Manager of RA Capital Healthcare Fund GP, LLC, the General Partner of RA Capital Healthcare Fund, L.P.</signatureName>
        <signatureDate>2024-06-10</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Peter Kolchinsky, Manager of RA Capital Nexus Fund II GP, LLC, the General Partner of RA Capital Nexus Fund II, L.P.</signatureName>
        <signatureDate>2024-06-10</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Peter Kolchinsky, individually</signatureName>
        <signatureDate>2024-06-10</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Rajeev Shah, individually</signatureName>
        <signatureDate>2024-06-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
