General Information

Luxturna (voretigene neparvovec) is a gene therapy for mutations in the RPE65 gene.

Luxturna is specifically indicated for vision loss due to confirmed biallelic RPE65-mediated inherited retinal disease.

Luxturna is supplied as as an intraocular suspension for subretinal injection. The recommended dose for each eye is 1.5 x 10(11) vector genomes, administered by subretinal injection in a total volume of 0.3mL. Luxturna should be administered to each eye on separate days but within a close interval, no fewer than 6 days apart.

Clinical Results

FDA Approval

The FDA approval of Luxturna was based on one open-label, dose-exploration Phase 1 safety study (n=12) and one open-label, randomized, controlled Phase III efficacy and safety study (n=31) in pediatric and adult participants (range 4 to 44 years) with biallelic RPE65 mutation-associated retinal dystrophy and sufficient viable retinal cells.

Of the 31 subjects enrolled in the Phase III study, 21 were randomized to receive subretinal injection of Luxturna and 10 were randomized to the control (non-intervention) group. One subject in the intervention group discontinued from the study prior to treatment and one subject in the control group withdrew consent and was discontinued from the study. All nine subjects randomized to the control group elected to crossover and receive Luxturna after one year of observation. The efficacy of was established based on the multi-luminance mobility test (MLMT) score change from baseline to one year. MLMT was designed to measure changes in functional vision as assessed by the ability of a participant to navigate a course accurately and at a reasonable pace at seven different levels of illumination, ranging from 400 lux (corresponding to a brightly lit office) to one lux (corresponding to a moonless summer night). Each light level was assigned a score ranging from zero to six, with a higher score indicating that a participant could pass MLMT at a lower light level. A score of negative one was assigned to participants who could not pass MLMT at a light level of 400 lux. MLMT score change was defined as the difference between the score at baseline and the score at one year with a positive score change indicating that a participant was able to complete MLMT at a lower light level. Additional clinical outcomes included white light full-field light sensitivity threshold (FST) testing and visual acuity. The phase III study results showed a statistically significant difference between the Luxturna group (n=21) and control group (n=10) at one year in median bilateral MLMT score change (intervention minus control group difference of 2; p=0.001) and median first-treated eye MLMT score change (intervention minus control group difference of 2; p=0.003). After crossing over to receive Luxturna, subjects in the control group showed a similar response to those in the intervention group. The median bilateral MLMT score change of two was observed for the intervention group at the 30-day timepoint. This change score was sustained for at least three years for the original intervention group and at least two years in the crossover group in the Phase III clinical study. In addition, subjects who received Luxturna showed a statistically significant improvement from baseline to one year in white light FST in the intervention group compared to the control group. The change in visual acuity from baseline to one year was not significantly different between the intervention and control groups.

Side Effects

Adverse effects associated with the treatment of Luxturna may include but are not limited to, the following:

conjunctival hyperemia

cataract

increased intraocular pressure

retinal tear, dellen (thinning of the corneal stroma)

macular hole

subretinal deposits

eye inflammation

eye irritation

eye pain

maculopathy

Mechanism of Action

Luxturna (voretigene neparvovec) is a gene therapy for mutations in the RPE65 gene. The therapy uses a neutralized virus as a vector, or delivery vehicle, to transport a functional gene into the affected tissue in the eye. Once inside the eye, the new genetic material enables patients to produce the protein that is missing as a result of their genetic mutation.