pEYS611-driven sustained human transferrin (TF) intraocular production in rats and rabbits. (A) The human TF expression cassette is composed of a human cytomegalovirus (CMV) enhancer, a chimeric CMV-HTLV (human T-cell leukemia virus)-I ubiquitous promoter, the ß-globin intron, and a Kozak sequence driving the expression of the human TF. (B,C) Human TF expression profiles in rat ocular fluids (B, n = 5–7 animals per timepoint) and rabbit aqueous humor and vitreous (C, n = 3–9 animals per timepoint) after bilateral ciliary muscle administration of pEYS611 at the doses of 30 and 45 µg/eye, respectively, demonstrated sustained expression of human TF for at least 3 and 6 months, in rat and rabbits, respectively. (D) Human TF distribution in rabbit eyes 28 days following pEYS611 administration demonstrated that the expressed protein reaches the back of the eye. Values are presented as mean ± sem.