Figure 1: DE-109 is injected IVT into the vitreous humour. Upon injection, excipients rapidly diffuse out of the formulation, and sirolimus forms a depot. Over time, the drug diffuses from the vitreous humour through the retina/choroid and into the sclera/subconjunctiva. A steady concentration is maintained in the vitreous humour and retina. Sirolimus is completely cleared.