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*
VENROCK HEALTHCARE CAPITAL PARTNERS LP

(Last) (First) (Middle)
C/O VENROCK
3340 HILLVIEW AVE.

(Street)
PALO ALTO CA 94304

(City) (State) (Zip)
2. Date of Event Requiring Statement (Month/Day/Year)
06/16/2015
3. Issuer Name and Ticker or Trading Symbol
ARCA biopharma, Inc. [ ABIO ]
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)
Common Stock 10,789,324 I(1)(3) By funds
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
Warrants (right to buy) 12/13/2015 06/16/2022 Common Stock 4,315,730 0.8716 I(2)(3) By funds
1. Name and Address of Reporting Person*
VENROCK HEALTHCARE CAPITAL PARTNERS LP

(Last) (First) (Middle)
C/O VENROCK
3340 HILLVIEW AVE.

(Street)
PALO ALTO CA 94304

(City) (State) (Zip)
1. Name and Address of Reporting Person*
Venrock Healthcare Capital Partners II, L.P.

(Last) (First) (Middle)
C/O VENROCK
3340 HILLVIEW AVE.

(Street)
PALO ALTO CA 94304

(City) (State) (Zip)
1. Name and Address of Reporting Person*
VHCP Co-Investment Holdings, LLC

(Last) (First) (Middle)
C/O VENROCK
3340 HILLVIEW AVE.

(Street)
PALO ALTO CA 94304

(City) (State) (Zip)
1. Name and Address of Reporting Person*
VHCP Co-Investment Holdings II, LLC

(Last) (First) (Middle)
C/O VENROCK
3340 HILLVIEW AVE.

(Street)
PALO ALTO CA 94304

(City) (State) (Zip)
1. Name and Address of Reporting Person*
Koh Bong Y

(Last) (First) (Middle)
C/O VENROCK
3340 HILLVIEW AVE.

(Street)
PALO ALTO CA 94304

(City) (State) (Zip)
1. Name and Address of Reporting Person*
Hove Anders D

(Last) (First) (Middle)
C/O VENROCK
530 FIFTH AVENUE

(Street)
NEW YORK NY 10036

(City) (State) (Zip)
1. Name and Address of Reporting Person*
VHCP Management, LLC

(Last) (First) (Middle)
C/O VENROCK
3340 HILLVIEW AVE.

(Street)
PALO ALTO CA 94304

(City) (State) (Zip)
1. Name and Address of Reporting Person*
VHCP Management II, LLC

(Last) (First) (Middle)
C/O VENROCK
3340 HILLVIEW AVE.

(Street)
PALO ALTO CA 94304

(City) (State) (Zip)
Explanation of Responses:
1. Consists of: 2,736,388 shares held directly by Venrock Healthcare Capital Partners, L.P. ("VHCP"); 5,373,623 shares held directly by Venrock Healthcare Capital Partners II, L.P. ("VHCP II"); 500,409 shares held directly by VHCP Co-Investment Holdings, LLC ("Co-Invest"); and 2,178,904 shares held directly by VHCP Co-Investment Holdings II, LLC ("Co-Invest II").
2. Consists of: 1,094,555 warrants held directly by VHCP; 2,149,449 warrants held directly by VHCP II; 200,164 warrants held directly by Co-Invest; and 871,562 warrants held directly by Co-Invest II.
3. VHCP Management, LLC ("VHCP Management") 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 ("VHCP Management II") is the general partner of VHCP II and the manager of Co-Invest II and may be deemed to beneficially own these shares. Drs. Anders D. Hove and Bong Y. Koh are the managing members of VHCP Management and VHCP Management II and may be deemed to beneficially own these shares. Drs. Hove and Koh, VHCP Management and VHCP Management II expressly disclaim beneficial ownership over these shares and warrants except to the extent of their indirect pecuniary interests therein.
Remarks:
/s/ David L. Stepp, Authorized Signatory 06/17/2015
/s/ David L. Stepp, as attorney in fact 06/17/2015
/s/ David L. Stepp, as attorney in fact 06/17/2015
** Signature of Reporting Person Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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