The procedure has been standardized with a standard small-gauge vitrectomy to perform a core vitrectomy performed under local anesthesia in the operating room. The delivery of the drug is done with a MedOne Microdose injector with a 38-gauge subretinal cannula attached to the vitrectomy machine.
The investigators are injecting 250 mcL subretinally into a healthy retinal tissue. They are targeting an area superior to the superotemporal arcade vessel or outside the arcades.
Dr. Heier explained that, if needed, a second bleb area could be selected. The bleb margin will be away from the fovea by at least 2 disc areas.
When the procedure is complete, an air-fluid exchange is performed and subconjunctival steroids are administered. The patients are not required to maintain a facedown position after surgery. They return for a follow-up evaluation the following day.
No major complications have reported in association with the treatment in the several patients who have undergone the procedure, Dr. Heier reported.
“Gene therapy for neovascular AMD offers the potential to alleviate the patients’ treatment burden,” Dr. Heier explained. “Other gene therapy studies for wet AMD conducted to date have indicated problems with protein expression. However, it is our hope that RGX-314 will have higher levels of protein.
“Designing a surgical trial for a medical disease is challenging,” he added. “The standardization and reproducibility of the procedure are the keys to success.”