Fusion proteins for ophthalmology with increased eye retention

The combination of a first binding site specifically binding to a target associated with an eye disease and a second binding site specifically binding to a target influencing the retention in the eye a multispecific binder provides for improved intravitreal retention compared to a monospecific binder. The second binding site specifically binds to a compound/molecules found in the extracellular matrix (ECM) in vitreous humor/retina. This compound of the extracellular matrix has to be present in amounts allowing a sufficient loading/dose of the drug to be bound. It has been found that collagen, especially collagen II, is a suitable compound in the ECM in the vitreous humor for this purpose. Thus, herein is reported a multispecific binder comprising a first binding site specifically binding to a therapeutic ocular target, and a second binding site specifically binding to collagen II.