<SEC-DOCUMENT>0001458177-18-000001.txt : 20180228
<SEC-HEADER>0001458177-18-000001.hdr.sgml : 20180228
<ACCEPTANCE-DATETIME>20180228160920
ACCESSION NUMBER:		0001458177-18-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180226
FILED AS OF DATE:		20180228
DATE AS OF CHANGE:		20180228

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Shah Nimish P
		CENTRAL INDEX KEY:			0001698082

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22873
		FILM NUMBER:		18651187

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		212-444-4087

	MAIL ADDRESS:	
		STREET 1:		530 FIFTH AVENUE
		CITY:			NEW YORK CITY
		STATE:			NY
		ZIP:			10036

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Koh Bong Y
		CENTRAL INDEX KEY:			0001615979

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22873
		FILM NUMBER:		18651188

	MAIL ADDRESS:	
		STREET 1:		3340 HILLVIEW AVENUE
		CITY:			PALO ALTO
		STATE:			CA
		ZIP:			94304

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VENROCK HEALTHCARE CAPITAL PARTNERS LP
		CENTRAL INDEX KEY:			0001458177
		STATE OF INCORPORATION:			DE

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22873
		FILM NUMBER:		18651194

	BUSINESS ADDRESS:	
		STREET 1:		530 FIFTH AVENUE
		STREET 2:		22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036
		BUSINESS PHONE:		650-475-3734

	MAIL ADDRESS:	
		STREET 1:		530 FIFTH AVENUE
		STREET 2:		22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Venrock Healthcare Capital Partners II, L.P.
		CENTRAL INDEX KEY:			0001602264
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22873
		FILM NUMBER:		18651191

	BUSINESS ADDRESS:	
		STREET 1:		530 FIFTH AVENUE
		STREET 2:		22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036
		BUSINESS PHONE:		650 475 3734

	MAIL ADDRESS:	
		STREET 1:		530 FIFTH AVENUE
		STREET 2:		22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VHCP Management II, LLC
		CENTRAL INDEX KEY:			0001602263
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22873
		FILM NUMBER:		18651189

	BUSINESS ADDRESS:	
		STREET 1:		530 FIFTH AVENUE
		STREET 2:		22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036
		BUSINESS PHONE:		650 475 3734

	MAIL ADDRESS:	
		STREET 1:		530 FIFTH AVENUE
		STREET 2:		22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VHCP Management, LLC
		CENTRAL INDEX KEY:			0001479355
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22873
		FILM NUMBER:		18651192

	BUSINESS ADDRESS:	
		STREET 1:		530 FIFTH AVENUE
		STREET 2:		22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036
		BUSINESS PHONE:		6504753734

	MAIL ADDRESS:	
		STREET 1:		530 FIFTH AVENUE
		STREET 2:		22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VHCP Co-Investment Holdings, LLC
		CENTRAL INDEX KEY:			0001479354
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22873
		FILM NUMBER:		18651193

	BUSINESS ADDRESS:	
		STREET 1:		530 FIFTH AVENUE
		STREET 2:		22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036
		BUSINESS PHONE:		650-475-3734

	MAIL ADDRESS:	
		STREET 1:		530 FIFTH AVENUE
		STREET 2:		22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VHCP Co-Investment Holdings II, LLC
		CENTRAL INDEX KEY:			0001615983
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22873
		FILM NUMBER:		18651190

	BUSINESS ADDRESS:	
		STREET 1:		530 FIFTH AVENUE
		STREET 2:		22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036
		BUSINESS PHONE:		650-475-3734

	MAIL ADDRESS:	
		STREET 1:		530 FIFTH AVENUE
		STREET 2:		22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ARCA biopharma, Inc.
		CENTRAL INDEX KEY:			0000907654
		STANDARD INDUSTRIAL CLASSIFICATION:	IN VITRO & IN VIVO DIAGNOSTIC SUBSTANCES [2835]
		IRS NUMBER:				363855489
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		11080 CIRCLEPOINT ROAD
		STREET 2:		SUITE 140
		CITY:			WESTMINSTER
		STATE:			CO
		ZIP:			80020
		BUSINESS PHONE:		720-940-2200

	MAIL ADDRESS:	
		STREET 1:		11080 CIRCLEPOINT ROAD
		STREET 2:		SUITE 140
		CITY:			WESTMINSTER
		STATE:			CO
		ZIP:			80020

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NUVELO INC
		DATE OF NAME CHANGE:	20030203

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	HYSEQ INC
		DATE OF NAME CHANGE:	19970610
</SEC-HEADER>
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        <issuerCik>0000907654</issuerCik>
        <issuerName>ARCA biopharma, Inc.</issuerName>
        <issuerTradingSymbol>ABIO</issuerTradingSymbol>
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            <rptOwnerCity>PALO ALTO</rptOwnerCity>
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            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PALO ALTO</rptOwnerCity>
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    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001615983</rptOwnerCik>
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    <reportingOwner>
        <reportingOwnerId>
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            <rptOwnerStreet1>3340 HILLVIEW AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PALO ALTO</rptOwnerCity>
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    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001615979</rptOwnerCik>
            <rptOwnerName>Koh Bong Y</rptOwnerName>
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            <rptOwnerStreet1>3340 HILLVIEW AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
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    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001698082</rptOwnerCik>
            <rptOwnerName>Shah Nimish P</rptOwnerName>
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            <rptOwnerStreet1>3340 HILLVIEW AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
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    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-02-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1500000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>.55</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>41331</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Funds</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-02-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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                <transactionShares>
                    <value>41331</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>.53</value>
                </transactionPricePerShare>
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                    <value>D</value>
                </transactionAcquiredDisposedCode>
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                <sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>I</value>
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        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.50 to $0.63, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (1) to this Form 4.</footnote>
        <footnote id="F2">Consists of: 10,482 shares held directly by Venrock Healthcare Capital Partners, L.P. (&quot;VHCP&quot;); 20,585 shares held directly by Venrock Healthcare Capital Partners II, L.P. (&quot;VHCP II&quot;); 1,917 shares held directly by VHCP Co-Investment Holdings, LLC (&quot;Co-Invest&quot;); and 8,347 shares held directly by VHCP Co-Investment Holdings II, LLC (&quot;Co-Invest II&quot;).</footnote>
        <footnote id="F3">VHCP Management, LLC (&quot;VHCP Management&quot;) is the general partner of VHCP and the manager of Co-Invest and may be deemed to beneficially own these shares. VHCP Management II, LLC (&quot;VHCP Management II&quot;) is the general partner of VHCP II and the manager of Co-Invest II and may be deemed to beneficially own these shares. Drs. Bong Koh and Nimish Shah are the managing members of VHCP Management and VHCP Management II and may be deemed to beneficially own these shares. Drs. Koh and Shah, VHCP Management and VHCP Management II expressly disclaim beneficial ownership over these shares except to the extent of their indirect pecuniary interests therein.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ David L. Stepp, Authorized Signatory</signatureName>
        <signatureDate>2018-02-28</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ David L. Stepp, as attorney in fact</signatureName>
        <signatureDate>2018-02-28</signatureDate>
    </ownerSignature>
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</SEC-DOCUMENT>
