Check the appropriate box to designate the rule pursuant to
which this Schedule is filed:
*The remainder of this cover page shall
be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.
The information required in the remainder of this cover page
shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“
Act
”)
or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however,
see the Notes).
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1.
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Names of Reporting Persons.
I.R.S. Identification Nos. of above persons (entities only).
RA Capital Management, LLC
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2.
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Check the Appropriate Box if a Member of a Group (See Instructions)
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|
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(a)
¨
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(b)
¨
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3.
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SEC Use Only
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4.
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Citizenship or Place of Organization
Massachusetts
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Number of
Shares
Beneficially
Owned by
Each Reporting
Person With
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5.
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Sole Voting Power
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0 shares
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6.
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Shared Voting Power
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556,735
1
shares
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7.
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Sole Dispositive Power
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0 shares
|
|
8.
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Shared Dispositive Power
|
556,735
1
shares
|
|
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9.
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Aggregate Amount Beneficially Owned by Each Reporting Person
556,735
1
shares
|
|
|
10.
|
Check
if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)
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¨
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11.
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Percent of Class Represented by Amount in Row (9)
5.9%
2
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12.
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Type of Reporting Person (See Instructions)
IA
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1
The shares reported herein for the Reporting Person represent (i) 232,245 shares of the Issuer’s Common Stock
beneficially owned and (ii) 324,490 shares of the Issuer’s Common Stock the reporting person has the right to acquire through
the exercise of warrants dated June 16, 2015 (“Warrant Shares”).
2
The percentage calculation assumes (i) 9,082,366 outstanding shares of Common Stock of the Issuer, based on the Issuer’s
Form 10-Q as filed with the Securities and Exchange Commission (“SEC”) on November 14, 2016, plus (ii) 324,490 shares
of the Issuer’s Common Stock the reporting person has the right to acquire through the exercise of Warrant Shares.
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1.
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Names of Reporting Persons.
I.R.S. Identification Nos. of above persons (entities only).
Peter Kolchinsky
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2.
|
Check the Appropriate Box if a Member of a Group (See Instructions)
|
|
|
(a)
¨
|
|
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(b)
¨
|
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3.
|
SEC Use Only
|
|
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4.
|
Citizenship or Place of Organization
United States
|
|
Number of
Shares
Beneficially
Owned by
Each Reporting
Person With
|
5.
|
Sole Voting Power
|
0 shares
|
|
|
6.
|
Shared Voting Power
|
556,735
1
shares
|
|
7.
|
Sole Dispositive Power
|
0 shares
|
|
8.
|
Shared Dispositive Power
|
556,735
1
shares
|
|
|
9.
|
Aggregate Amount Beneficially Owned by Each Reporting Person
556,735
1
shares
|
|
|
10.
|
Check
if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)
|
¨
|
|
|
11.
|
Percent of Class Represented by Amount in Row (9)
5.9%
2
|
|
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12.
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Type of Reporting Person (See Instructions)
IN
|
|
|
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1
The shares reported herein for the Reporting Person represent (i) 232,245 shares of the Issuer’s Common Stock
beneficially owned and (ii) 324,490 shares of the Issuer’s Common Stock the reporting person has the right to acquire through
the exercise of warrants dated June 16, 2015 (“Warrant Shares”).
2
The percentage calculation assumes (i) 9,082,366 outstanding shares of Common Stock of the Issuer, based on the Issuer’s
Form 10-Q as filed with the Securities and Exchange Commission (“SEC”) on November 14, 2016, plus (ii) 324,490 shares
of the Issuer’s Common Stock the reporting person has the right to acquire through the exercise of Warrant Shares.
Item 1.
(a)
Name of Issuer:
ARCA biopharma,
Inc. (the “Issuer”).
(b)
Address of the Issuer’s
Principal Executive Offices:
11080 CirclePoint Road, Suite 140, Westminster, CO 80020.
Item 2.
(a)
Name of Person
Filing:
This joint statement on Schedule 13G is being filed by RA Capital Management, LLC (“Capital”) and Peter
Kolchinsky. Capital and Mr. Kolchinsky are collectively referred to herein as the “Reporting Persons.” Capital is
the general partner of the RA Capital Healthcare Fund, L.P. (the “Fund”) and serves as investment adviser for a separately
managed account (the “Account”). Mr. Kolchinsky is the manager of Capital. As the investment adviser to the Fund and
the Account, Capital may be deemed a beneficial owner, for purposes of Section 13(d) of the Securities Exchange Act of 1934 (the
“Act”), of any securities of the Issuer owned by the Fund or the Account. As the manager of Capital, Mr. Kolchinsky
may be deemed a beneficial owner, for purposes of Section 13(d) of the Act, of any securities of the Issuer beneficially owned
by Capital. Capital and Mr. Kolchinsky disclaim beneficial ownership of the securities reported in this Schedule 13G Statement
(the “Statement”) other than for the purpose of determining their obligations under Section 13(d) of the Act, and
neither the filing of the Statement nor the filing of this Amendment shall be deemed an admission that either Capital or Mr. Kolchinsky
is or was the beneficial owner of such securities for any other purpose.
(b)
Address of
Principal Business Office:
The principal business office of the Reporting Persons is c/o RA Capital Management, LLC, 20 Park
Plaza, Suite 1200, Boston, MA 02116.
(c)
Citizenship:
Capital is a Massachusetts limited liability company. Mr. Kolchinsky is a United States citizen.
(d)
Title and
Class of Securities:
Common stock (“Common Stock”)
(e)
CUSIP Number:
00211Y407
Item 3. If this statement is filed
pursuant to §§240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(e) RA Capital Management LLC is a registered investment adviser
and is filing this statement in accordance with §240.13d-1(b)(1)(ii)(E);
(g) Peter Kolchinsky is a control person and is filing this
statement in accordance with §240.13d-1(b)(1)(ii)(G).
Item 4. Ownership:
Provide the following information regarding
the aggregate number and percentage of the class of securities of the issuer identified in Item 1.
(a)
|
Amount Beneficially Owned:
See the response(s) to Item 9 on the attached cover
page(s).
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(b)
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Percent of Class:
See the response(s) to Item 11 on the attached cover
page(s).
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(c)
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Number of shares as to which such person has:
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(i)
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sole power to vote or to direct the vote:
See the response(s) to Item 5 on the attached cover
page(s).
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(ii)
|
shared power to vote or to direct the vote
See the response(s) to Item 6 on the attached cover
page(s).
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(iii)
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sole power to dispose or to direct the disposition
of
See the response(s) to Item 7 on the attached cover
page(s).
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(iv)
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shared power to dispose or to direct the disposition
of
See the response(s) to Item 8 on the attached cover
page(s).
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Item 5. Ownership of Five Percent
or Less of a Class:
Not applicable.
Item 6. Ownership
of More than Five Percent on Behalf of Another Person:
Not applicable.
Item 7. Identification and Classification
of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person:
Not applicable.
Item 8. Identification and Classification
of Members of the Group:
Not applicable.
Item 9. Notice of Dissolution of
Group:
Not applicable.
Item 10. Certification:
By signing below I hereby certify that,
to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of
or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held
in connection with or as a participant in any transaction having that purpose or effect.
Exhibits
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1
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Joint Filing Agreement by and among the Reporting Persons is incorporated
herein by reference to Exhibit 1 to the Schedule 13G filed by the Reporting Persons with
the Securities and Exchange Commission on June 25, 2015.
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SIGNATURE
After reasonable inquiry
and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.
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Date: F
ebruary 14
,
2017
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RA CAPITAL MANAGEMENT, LLC
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By: /s/ Rajeev Shah
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Rajeev Shah
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Authorized Signatory
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PETER KOLCHINSKY
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/s/ Peter Kolchinsky
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