Sec Form 4/A Filing - Brown Bob D @ Dicerna Pharmaceuticals Inc - 2021-02-03

FORM 4/A Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Brown Bob D 2. Issuer Name and Ticker or Trading Symbol Dicerna Pharmaceuticals Inc [ DRNA] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Chief Scientific Ofr., EVP R&D (Last) (First) (Middle) C/O DICERNA PHARMACEUTICALS, INC., 75 HAYDEN AVENUE 3. Date of Earliest Transaction (MM/DD/YY) 02/03/2021 (Street) LEXINGTON, MA02421 4. If Amendment, Date Original Filed (MM/DD/YY) 02/04/2021 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 02/03/2021 M 3,066 ( 1 ) A $ 3.42 ( 1 ) 24,583 ( 1 ) D Common Stock 02/03/2021 M 5,246 ( 1 ) A $ 2.97 ( 1 ) 29,829 D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Employee Stock Option (Right to Buy) $ 3.42 ( 1 ) 02/03/2021 M 3,066 ( 1 ) ( 1 )( 2 ) 09/24/2023( 1 ) Common Stock 3,066 ( 1 ) $ 0 74,808 ( 1 ) D Employee Stock Option (Right to Buy) $ 2.97 ( 1 ) 02/03/2021 M 5,246 ( 1 ) ( 1 )( 3 ) 01/03/2027( 1 ) Common Stock 5,246 ( 1 ) $ 0 0 ( 1 ) D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Brown Bob D C/O DICERNA PHARMACEUTICALS, INC. 75 HAYDEN AVENUE LEXINGTON, MA02421 Chief Scientific Ofr., EVP R&D Signatures /s/ Douglas W. Pagan, attorney-in-fact 04/05/2021 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The Reporting Person's original Form 4 as filed with the Securities and Exchange Commission on February 4, 2021 (the "Original Form 4") is hereby amended to reflect the correct option grants from which the shares were exercised. The aggregate total number of shares exercised (8,312 shares) was correctly reported in the Original Form 4. Except as noted in this amended Form 4, all other information disclosed in the Original Form 4 was accurately reported and remains unchanged. ( 2 )As of the transaction date, the option was fully vested. The option vested 1/48 monthly on the last day of each month with the vesting start date of 7/30/2013. ( 3 )The option vests in 48 monthly installments over the four-year period starting on the last day of January 2017, subject in each case to the Reporting Person's continued service with the Issuer through the applicable vesting 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 4(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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