X0306 4 2020-01-17 0 0001399529 Dicerna Pharmaceuticals Inc DRNA 0001243847 GREEN JOHN B C/O DICERNA PHARMACEUTICALS, INC. 33 HAYDEN AVENUE LEXINGTON MA 02421 0 1 0 0 Chief Financial Officer Common Stock 2020-01-17 4 M 0 27500 2.97 A 46921 D Common Stock 2020-01-17 4 M 0 20469 2.97 A 67390 D Common Stock 2020-01-17 4 S 0 27500 21.2704 D 39890 D Common Stock 2020-01-17 4 S 0 20469 21.2628 D 19421 D Employee Stock Option (Right to Buy) 2.97 2020-01-17 4 M 0 27500 0.00 D 2027-01-03 Common Stock 27500 47500 D Employee Stock Option (Right to Buy) 2.97 2020-01-17 4 M 0 20469 0.00 D 2027-01-03 Common Stock 20469 27031 D Includes shares acquired under the DRNA 2014 Employee Stock Purchase Plan in transactions that were exempt under Rule 16b-3(c). The reporting person sold an aggregate of 47,969 shares of common stock on January 17, 2020 (the "Shares Sold") as reported in this Form 4. The Shares Sold represent 6.78% of 707,021 shares of common stock, which is the number of shares of common stock owned by the reporting person prior to the Shares Sold transactions reported in this Form 4, as well as shares issuable upon exercise or settlement of vested and unvested options and restricted stock units held by the reporting person as of the date of this report. The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 17, 2019. The price reported in Column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $21.10 to $21.51, inclusive. The reporting person undertakes to provide to Dicerna Pharmaceuticals, Inc., any security holder of Dicerna Pharmaceuticals, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (4) to this Form 4. The price reported in Column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $21.10 to $21.51, inclusive. The reporting person undertakes to provide to Dicerna Pharmaceuticals, Inc., any security holder of Dicerna Pharmaceuticals, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (5) to this Form 4. 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. /s/ John B. Green 2020-01-21