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* RA CAPITAL MANAGEMENT, LLC (Last) (First) (Middle) C/O RA CAPITAL MANAGEMENT, LLC 20 PARK PLAZA, SUITE 1200 (Street) BOSTON MA 02116 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 01/29/2014	3. Issuer Name and Ticker or Trading Symbol Dicerna Pharmaceuticals Inc [ DRNA ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) X Other (specify below) Peter Kolchinsky is director	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)

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
Series C Preferred Stock, par value $0.0001	01/29/2014	(1)	Common Stock	1,428,571(1)	(1)	I	See Footnote(2)(3)

1. Name and Address of Reporting Person* RA CAPITAL MANAGEMENT, LLC (Last) (First) (Middle) C/O RA CAPITAL MANAGEMENT, LLC 20 PARK PLAZA, SUITE 1200 (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) X Other (specify below) Peter Kolchinsky is director

1. Name and Address of Reporting Person* Kolchinsky Peter (Last) (First) (Middle) C/O RA CAPITAL MANAGEMENT, LLC 20 PARK PLAZA, SUITE 1200 (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* RA Capital Healthcare Fund LP (Last) (First) (Middle) C/O RA CAPITAL MANAGEMENT, LLC 20 PARK PLAZA, SUITE 1200 (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. These shares include 1,428,571 Series C Preferred Shares held by RA Capital Healthcare Fund, L.P. (the "Fund"), which are convertible into the Issuer's Common Stock on a one-for-one basis. The Series C Preferred Shares are to convert into shares of the Issuer's Common Stock upon the closing of the Issuer's initial public offering of Common Stock. The Series C Preferred Shares have no expiration date.

2. RA Capital Management, LLC (the "Adviser") is the general partner of the Fund. Peter Kolchinsky is the sole manager of the Adviser. In their respective capacities, each of Mr. Kolchinsky and the Adviser may be deemed to beneficially own the reported securities. In addition, Mr. Kolchinsky is a director of the Issuer.

3. Pursuant to Rule 16a-1 under the Securities Exchange Act of 1934, as amended (the "Act"), each of the Reporting Persons disclaims beneficial ownership of the securities reported herein except to the extent of their respective pecuniary interests therein. The filing of this Form 4 shall not be construed as an admission that Mr. Kolchinsky or the Adviser is or was for the purposes of Section 16(a) of the Act, or otherwise, the beneficial owner of any of securities reported herein.

	/s/ Peter Kolchinsky, Manager of RA Capital Management, LLC	01/29/2014
	/s/ Peter Kolchinsky, individually	01/29/2014
	/s/ Peter Kolchinsky, Manager of RA Capital Management, LLC, the General Partner of RA Capital Healthcare Fund, L.P.	01/29/2014
	** Signature of Reporting Person	Date
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