Unassociated Document

Joint Filer Information

Names:	Deerfield Mgmt, L.P., Deerfield Management Company, L.P., Deerfield Special Situations Fund, L.P., Deerfield Special Situations International Master Fund, L.P., Deerfield Private Design Fund II, L.P., Deerfield Private Design International II, L.P.

Address:	780 Third Avenue, 37th Floor New York, NY 10017

Designated Filer:	James E. Flynn

Issuer and Ticker Symbol:	Dicerna Pharmaceuticals, Inc. [DRNA]

Date of Earliest Transaction Reported:	January 29, 2014

The undersigned, Deerfield Mgmt, L.P., Deerfield Management Company, L.P., Deerfield Special Situations Fund, L.P., Deerfield Special Situations International Master Fund, L.P., Deerfield Private Design Fund II, L.P. and Deerfield Private Design International II, L.P. are jointly filing the attached Initial Statement of Beneficial Ownership on Form 3 with James E. Flynn with respect to the beneficial ownership of securities of Dicerna Pharmaceuticals, Inc.

Signatures:

DEERFIELD MGMT, L.P.

By: J.E. Flynn Capital LLC, General Partner

By: /s/ Jonathan Isler