A recently completed non-human primate study of VGX-0111 demonstrated good tolerability, provided strong transgene expression in the targeted region of the retina, and increased production of the lipids whose decline is associated with macular degeneration.
Visgenx Inc. announced positive data from a non-human primate translational study that used a single subretinal injection to deliver VGX-0111 (carrying an ELOVL2 transgene) to investigate whether VGX-0111 expresses in the target tissues and causes an increase in certain very long-chain polyunsaturated fatty acids at a dose that is well tolerated. VGX-0111 was able to successfully demonstrate all 3 of these important parameters.
According to the company, dry age-related macular degeneration (AMD) is a leading cause of blindness. Researchers noted the underlying cause of dry AMD remains unknown, though recent studies suggest that a decline in the biosynthesis of certain long chain and very long chain polyunsaturated fatty acids (LC and VLC PUFA) plays an important underlying role. The ELOVL2 enzyme plays a central role in the biosynthesis of LC and VLC PUFAs.
The company noted that during aging, expression of the ELOVL2 gene declines leading to a reduction in the LC and VLC PUFAs necessary for vision. VGX-0111 is an experimental gene therapy intended to increase expression of ELOVL2. It is thought that restoring physiological ELOVL2 expression will increase levels of LC and VLC PUFAs in the retina and slow or halt the progression of dry AMD.
According to the news release, studies in natural aging models of dry AMD in rodents have demonstrated that a single treatment with VGX-0111 increased ELOVL2 expression and protected against photoreceptor loss. The recently completed study investigated VGX-0111 in non-human primates as the next step toward human clinical trials.
Moreover, the company noted in its release the studies showed VGX -0111 was well tolerated and expressed appropriately in the targeted areas of the retina. Most importantly, the study demonstrated a meaningful increase in the LC and VLC PUFAs whose deficit is associated with dry AMD.
Martin Emanuele, PhD, chief science officer of Visgenx, noted in the news release the results proved to be encouraging and worthy of further investigation.
"A robust body of scientific literature supports that long chain and very long chain polyunsaturated fatty acids play essential roles in both the vision transduction process and supporting the bioenergetics of retinal function," Emanuele said in the release. "The findings demonstrate that it is possible to increase the fatty acids whose decline is associated with dry AMD with a well-tolerated treatment in a species closely related to humans."