Posterior juxtascleral depot administration of anecortave acetate

Objective: To develop a safe and effective transcleral delivery of anecortave acetate, a novel angiostatic cortisene, in therapeutic concentrations to the choroid and retina in the region of the macula in patients with age related macular degeneration.

Methods: In pre-clinical studies with rabbits and monkeys, several routes of delivery were studied including oral and other systemic routes as well as topical, subconjunctival, intravitreal injections and posterior juxtascleral administration. In addition, posterior juxtascleral depot administration using a specially designed blunt cannula was evaluated in humans.

Results: Oral and other systemic routes were not acceptable due to rapid systemic metabolism. Topical and subconjunctival administrations resulted in subtherapeutic concentrations in the macular region (<0.1 microm). Intravitreal injections resulted in adequate drug levels, but the visual axis was obscured due to the opaque nature of the drug, and this method carries risks of endophthalmitis and retinal detachment. Posterior juxtascleral depot administration in rabbits and monkeys resulted in adequate retinal and choroidal drug levels (>or=0.1 microm) up to 6 months after administration. In clinical studies, this administration technique was found to be safe.

Conclusions: Posterior juxtascleral depot administration of anecortave acetate onto the scleral surface near the macula is a safe and effective method for delivering therapeutic concentrations of drug to the macular region of the choroid and retina for up to 6 months.