Not a magic bullet
Dr. Levin pointed out that gene therapy with voretigene is not a magic bullet, even for patients who are appropriate candidates.
“We still have a lot to learn, and gene therapy needs to be more affordable and accessible,” Dr. Levin explained. “But the availability of this approved therapy that can deliver a replacement or repair mechanism for this one abnormal gene in the eye, halt progression of a retinal degeneration in some patients, and perhaps even restore sight brings us through a doorway to an exciting future.”
Voretigene is approved for use in patients aged ≥1 year who have viable retinal cells as determined by the treating physician. It is administered by subretinal injection (1.5 x 1011 vector genomes/0.3 mL) following vitrectomy.
Fellow eye procedures may be performed within a short timeframe, but with a minimum of six days between eyes. It is recommended that patients receive a systemic oral corticosteroid beginning three days prior to treatment to each eye. The recommended daily dose is prednisone equivalent 1 mg/kg (maximum 40 mg) for seven days followed by a taper during the next 10 days.
The treatment delivers a normal copy of the gene encoding the RPE65 protein to RPE cells. It thereby has the potential to restore the visual cycle and vision in individuals with RPE65 gene mutations, who have reduced or absent levels of RPE65.