Spark Therapeutics shares jump 59% on positive Phase III results

Philadelphia-based biotech company Spark Therapeutics (Nasdaq: ONCE) has reported that the Phase III trial of the gene therapy SPK-RPE65 to treat RPE65-mediated inherited retinal dystrophies has met its primary endpoint.

The therapy demonstrated an improvement of functional vision compared to the control arm, as measured by the change in bilateral mobility testing between baseline and one year. Spark intends to file an application with the US Food and Drug Administration in 2016.

In the study, 31 patients with RPE65 gene mutations were randomized so that 21 received SPK-RPE65 and 10 were in the control group. Subjects were evaluated over the course of one year for their performance in navigating a mobility course in different light levels using the bilateral testing condition. Secondary endpoints included full-field light sensitivity threshold testing and change in mobility test score for the first eye injected. Although those secondary endpoints were met, the final one, visual acuity, did not show statistically significant evidence of benefit.