Bevasiranib reaches the retina

Bevasiranib, a small interfering RNA (siRNA) compound targeting vascular endothelial growth factor-A (VEGF-A), is distributed throughout the eye, including the retina, according to a study published on 28 May 2008 in Molecular Vision.

Nadine S. Dejneka, of OPKO Ophthalmics, US, and colleagues conducted a tissue distribution and pharmacokinetic study to determine how a single intravitreal injection (either 0.5 or 2.0 mg/eye) of bevasiranib, developed by OPKO Health Inc., US, was distributed in rabbit eyes (64 eyes of 32 rabbits).

Twenty-four hours post-injection, bevasiranib was detected in the vitreous, iris, retina, retinal pigment epithelium (RPE), and sclera (+choroid). After the initial 24 hours, levels of bevasiranib in the vitreous began to drop; maximum saturation in non-vitreous ocular tissues was reached up to 72 hours post-injection.

The researchers believe that these results of distribution to the retina provide significant evidence for the use of bevasiranib against wet age-related macular degeneration (AMD), as is currently being evaluated in the international Phase III COBALT study.