On November 23, 2018, Spark Therapeutics, Inc. (the “Company”) issued a press release announcing that the European Commission has granted marketing authorization for LUXTURNA® (voretigene neparvovec), aone-time gene therapy for the treatment of adult and pediatric patients with vision loss due to inherited retinal dystrophy caused by confirmed biallelicRPE65 mutations and who have sufficient viable retinal cells.RPE65-mediated inherited retinal disease is a progressive condition leading to total blindness in most patients. This authorization is valid in all28-member states of the EU, as well as Iceland, Liechtenstein and Norway. LUXTURNA is the first gene therapy for a genetic disease that has received regulatory approval in both the U.S. and EU. Under the terms of the License and Commercialization Agreement between the Company and Novartis Pharma AG (“Novartis”), upon receipt of the marketing authorization for LUXTURNA, the Company is entitled to a $25 million payment from Novartis.
Clinical Trial Overview of LUXTURNA® (voretigene neparvovec)
The safety and efficacy of LUXTURNA were assessed in one open-label, dose-exploration Phase 1 safety study (n=12), a second open-label Phase 1follow-on study to assess the safety of injection of the contralateral eye (n=11) and an open-label, randomized, controlled Phase 3 efficacy and safety study (n=31) in pediatric and adult participants (range 4 to 44 years) with biallelicRPE65 mutation-associated retinal disease and sufficient viable retinal cells.
Of the 31 participants enrolled in the Phase 3 study, 21 were randomized to receive subretinal injection of LUXTURNA and 10 were randomized to the control(non-intervention) group. One participant in the intervention group discontinued from the study prior to treatment and one participant in the control group withdrew consent and was discontinued from the study. All nine participants randomized to the control group elected to cross over to receive LUXTURNA after one year of observation. All participants in these studies planned to be followed for long-term safety and efficacy. LUXTURNA Phase 3 clinical trial data, including data from the intervention group of all randomized participants through theone-year time point, have been previously reported inThe Lancet.
The efficacy of LUXTURNA in the Phase 3 study was established based on the binocular 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, both averaged over both eyes.
LUXTURNA Phase 3 clinical study results showed a statistically significant difference between the intervention group (n=21) and control participants (n=10) at one year in mean binocular MLMT score change (intervention minus control group difference of 1.6; 95% CI, 0.72, 2.41;p=0.001). After crossing over to receive LUXTURNA, participants in the control group showed a similar response to those in the intervention group. This score change has been sustained for at least three years for the original intervention group and at least two years in the crossover group of the Phase 3 clinical study. In addition, participants who received LUXTURNA showed a statistically significant improvement from baseline to one year in white light FST averaged over both eyes (p<0.001) and first assigned eye MLMT change score (p=0.001) compared to the control group. The change in visual acuity from baseline to one year was not significantly different between the intervention and control participants.