X0306 4 2019-12-04 0 0001399529 Dicerna Pharmaceuticals Inc DRNA 0001578965 Koppel Adam C/O BAIN CAPITAL LIFE SCIENCES INVESTORS LLC 200 CLARENDON STREET BOSTON MA 02116 1 0 0 0 Common Stock 2019-12-04 4 S 0 1500000 24.68 D 4080237 I See footnotes Represents shares of common stock held directly by Bain Capital Life Sciences Fund, L.P. ("BCLS") and BCIP Life Sciences Associates, LP ("BCIP LS" and, together with BCLS, the "Bain Capital Life Sciences Entities"). Bain Capital Life Sciences Investors, LLC ("BCLSI") is the ultimate general partner of BCLS and governs the investment strategy and decision-making process on behalf of BCIP LS. Dr. Koppel is a Managing Director of BCLSI. By virtue of the relationships described in this footnote, Dr. Koppel may be deemed to share voting and dispositive power with respect to the shares of common stock held by the Bain Capital Life Sciences Entities. Dr. Koppel disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein. /s/ Adam Koppel 2019-12-06