Hope on the Horizon: Gene Therapy Candidate for Dry AMD Shows Positive Translational Study Results
For individuals and families navigating the challenges of inherited retinal diseases (IRDs), news of advancements in gene therapy offers a beacon of hope. While dry Age-related Macular Degeneration (AMD) is primarily an age-related condition, its impact on central vision and the retina shares similarities with various IRDs. Breakthroughs in treating conditions like dry AMD, which affects nearly 200 million people globally, can often pave the way for broader applications and a deeper understanding of retinal degenerations, benefiting the entire IRD community.
Visgenx, Inc., a biotechnology company focused on gene-based therapeutics for degenerative retinal diseases, recently announced positive results from a key translational study for its gene therapy candidate, VGX-0111, for dry AMD.
Key Findings from the Study
The study, conducted in non-human primates, investigated VGX-0111, which carries an ELOVL2 transgene. The primary goals were to determine if VGX-0111 could be delivered effectively, if it would express in the targeted retinal tissues, and if it would increase specific very long chain polyunsaturated fatty acids (LC and VLC PUFAs) at a well-tolerated dose.
According to Visgenx, VGX-0111 successfully demonstrated all three of these important parameters. The study showed good tolerability, strong transgene expression in the targeted region of the retina, and a meaningful increase in the lipids (LC and VLC PUFAs) whose decline is associated with macular degeneration. These fatty acids are understood to play essential roles in vision transduction and supporting the bioenergetics of retinal function.
What This Means for Patients and Families
Dry AMD is a leading cause of blindness, characterized by the deterioration of the macula, which is crucial for detailed central vision needed for activities like reading and recognizing faces. While the exact cause of dry AMD is not fully understood, recent studies suggest that a decline in the biosynthesis of certain LC and VLC PUFAs plays an important role. The ELOVL2 enzyme is central to this biosynthesis, and its expression declines with aging, leading to reduced levels of these vision-essential fatty acids.
VGX-0111 is an experimental gene therapy designed to increase ELOVL2 expression. The hope is that restoring physiological ELOVL2 expression could increase LC and VLC PUFAs in the retina, potentially slowing or halting the progression of dry AMD. Prior studies in rodent models of dry AMD had already indicated that a single treatment with VGX-0111 increased ELOVL2 expression and protected against photoreceptor loss.
These positive translational study results are a significant step forward, indicating that a well-tolerated treatment can increase these critical fatty acids in a species closely related to humans. Visgenx is now moving its development program forward with the intention of conducting a human proof-of-concept study.
This progress in gene therapy for dry AMD underscores the potential for similar gene-based approaches to address the underlying causes of various inherited retinal diseases, bringing us closer to effective treatments for a wide range of vision-threatening conditions.