MedicalResearch.com Interview with:
Prof Peter A Campochiaro MD
Director, Retinal Cell and Molecular Laboratory
Professor of Ophthalmology
Johns Hopkins University School of Medicine
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Patients with wet age-related macular degeneration (AMD) have increased levels of vascular endothelial growth factor (VEGF) in their eyes resulting in growth of abnormal blood vessels that leak fluid into the retina and reduce vision. The current treatment is to inject proteins that block VEGF which initially provides a very good effect, but repeated injections are needed.
Patients sometimes are unable to keep up the frequency of visits and injections needed to keep the disease quiet and over time there is often gradual loss of vision. The aim of this study was to test a new approach through which a viral vector is injected into the eye resulting in production of a protein that block VEGF in the eye reducing the need for repeated injections.
These are the major findings:
1) Intravitreous injection of an AAV2 vector expressing a protein that blocks vascular endothelial growth factor (VEGF) was safe and well-tolerated.
(2) 5 of 10 patients injected with the highest dose (2 × 10¹⁰ vector genomes) had measurable levels of the therapeutic protein in samples removed from the front of the eye- all of these patients had no or very low levels of anti-AAV2 serum antibodies and 4 of the 5 patients who did not show expression had high anti-AAV2 serum antibodies
(3) Eleven patients had fluid in or under the retina before vector injection and 6 of them showed substantial reduction of the fluid which is the desired outcome.