On Jul. 22, 2010, MDRNA announced that MDRNA shareholders approved the issuance of shares of MDRNA common stock in connection with the proposed acquisition of Cequent Pharmaceuticals. Marina Biotech acquired Cequent Pharmaceuticals for $44 million. To facilitate the merger the Company completed a 1-for-4 reverse split of its common stock.

The combined company was initially headquartered in Bothell, with offices in Cambridge, Massachusetts. In 2012, Marina Biotech announced the closure of Cambridge site and consolidation of R&D operations in Bothell. In November 2016, Marina Biotech announced a merger with Ithena Pharmlo, part of the Autotelic Inc. consortium companies, and the company relocated to City of Industry, CA.