Gene therapy biotech Spark Therapeutics ($ONCE) has posted new long-term data for its Phase III trial of voretigene neparvovec, an experimental treatment for patients with an inherited eye disorder.
The biotech has already released data for its Phase III 301 trial which saw it hit the primary endpoint of a change in bilateral mobility testing (MT). It also aced two out of three secondary endpoints, but missed a third--visual acuity (i.e., clarity of sight).
The biotech is testing its candidate in patients with inherited retinal disease (IRD) caused by mutations in the RPE65 gene.
In the longer term 302 study, 9 crossover patients were assessed after one year of using voretigene neparvovec in both eyes.
And 12 months down the line, 8 of the 9 subjects in the 302 study showed improved MT, with all 8 responders being able to show the maximum improvement measurable, according to a statement from the company.
But it was not all positive, as patients in the 302 study showed an average visual acuity improvement of just 4.5 letters (averaged across both eyes)--nearly 50% less than the average improvement of 8 letters by the same analysis in the 301 study.
Today, Spark published its latest follow-up data, showing that the durability of benefit from its drug was maintained for at least two years in the 20 patients coming out of the 301 study.
“We now have substantially more data at one year after administration of voretigene neparvovec across both the 301 and 302 Phase 3 studies, and have seen 27 of 29, or 93%, of subjects respond, importantly demonstrating gains in functional vision,” said Dr. Katherine High, president and chief scientific officer of Spark Therapeutics, in release. “We plan to include these additional Phase III data in the clinical modules of our rolling BLA submission, as well as to continue to analyze data from our clinical trials in order to further elucidate the potential for long-lasting benefit that voretigene neparvovec may have on the lives of patients with RPE65-mediated inherited retinal disease.”
- check out the release