Abbvie Inc. and Regenxbio Inc. have announced a partnership to develop and commercialize RGX-314, a potential one-time gene therapy for the treatment of wet age-related macular degeneration (wet AMD), diabetic retinopathy and other chronic retinal diseases. Under the terms of the agreement, Abbvie will pay Regenxbio $370 million up front, plus up to $1.38 billion in additional development, regulatory and commercial milestones. The deal gives '314 – already the most advanced gene therapy in wet AMD – another potential edge against its nearest competitor, Adverum Biotechnologies Inc.’s ADVM-022.