UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No.     )

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¨ Preliminary Proxy Statement

¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

¨ Definitive Proxy Statement

x Definitive Additional Materials

¨ Soliciting Material Pursuant to §240.14a-12

Dicerna Pharmaceuticals, Inc.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

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*** Exercise Your Right to Vote ***

Important Notice Regarding the Availability of Proxy Materials for the

Shareholder Meeting to Be Held on June 25, 2015

	Meeting Information
DICERNA PHARMACEUTICALS, INC.	Meeting Type: Annual Meeting
	For holders as of: April 27, 2015
	Date: June 25, 2015	Time: 9:00 AM EST
	Location:  87 Cambridgepark Drive
	Cambridge, MA 02140

DICERNA PHARMACEUTICALS, INC. 87 CAMBRIDGEPARK DRIVE CAMBRIDGE, MA 02140	You are receiving this communication because you hold shares in the above named company.
	This is not a ballot. You cannot use this notice to vote these shares. This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. You may view the proxy materials online at www.proxyvote.com or easily request a paper copy (see reverse side).
	We encourage you to access and review all of the important information contained in the proxy materials before voting.

See the reverse side of this notice to obtain proxy  materials and voting instructions.

Before You Vote  

How to Access the Proxy Materials

Proxy Materials Available to VIEW or RECEIVE:

1. Annual Report         2. Notice and Proxy Statement

How to View Online:

Have the information that is printed in the box marked by the arrow     (located on the following page) and visit: www.proxyvote.com.

How to Request and Receive a PAPER or E-MAIL Copy:

If you want to receive a paper or e-mail copy of these documents, you must request one. There is NO charge for requesting a copy. Please choose one of the following methods to make your request:

                               1) BY INTERNET:         www.proxyvote.com

                               2) BY TELEPHONE:     1-800-579-1639

                               3) BY E-MAIL*:             sendmaterial@proxyvote.com

*  If requesting materials by e-mail, please send a blank e-mail with the information that is printed in the box marked by the arrow     (located on the following page) in the subject line.

Requests, instructions and other inquiries sent to this e-mail address will NOT be forwarded to your investment advisor. Please make the request as instructed above on or before June 11, 2015 to facilitate timely delivery.

How To Vote  

Please Choose One of the Following Voting Methods

Vote In Person: Many shareholder meetings have attendance requirements including, but not limited to, the possession of an attendance ticket issued by the entity holding the meeting. Please check the meeting materials for any special requirements for meeting attendance. At the meeting, you will need to request a ballot to vote these shares. Vote By Internet: To vote now by Internet, go to www.proxyvote.com. Have the information that is printed in the box marked by the arrow     available and follow the instructions. Vote By Mail: You can vote by mail by requesting a paper copy of the materials, which will include a proxy card.

	Voting items
	The Board of Directors recommends you vote FOR the following:
	1.    Election of Directors
	Nominees
	1a    Douglas M. Fambrough
	1b    Brian K. Halak
	1c    Stephen J. Hoffman
	1d    Peter Kolchinsky
	1e    Dennis H. Langer
	1f    David M. Madden
	1g    Bruce Peacock
	The Board of Directors recommends you vote FOR proposals 2 and 3.
	2     To ratify the selection of Deloitte &        Touche LLP as our independent registered        public accounting firm for the fiscal        year ending December 31, 2015
	3     To adopt and approve our Amended and        Restated 2014 Performance Incentive Plan
	NOTE: Such other business as may properly come before the meeting or any adjournment thereof.