GenSight Biologics has reported positive results from week 96 of the Reverse Phase III clinical trial that evaluated the safety and efficacy of a single intravitreal injection of GS010 in patients suffering from visual loss due to Leber hereditary optic neuropathy (LHON).
Visual loss started between six and 12 months prior to study treatment and week 96 is the last of the scheduled readouts for the trial.
Rescue and Reverse are two randomised, double-masked, sham-controlled Phase III trials to evaluate the efficacy of a single intravitreal injection of GS010 in subjects affected by LHON due to the G11778A mutation in the mitochondrial ND4 gene.
The primary endpoint will measure the difference in efficacy of GS010 in treated eyes compared to sham-treated eyes based on best-corrected visual acuity (BCVA), measured with the ETDRS at 48 weeks post-injection.
GenSight claimed that the findings reveal continued efficacy of GS010 two years past injection, with BCVA sustaining a clinically meaningful improvement over baseline.
It said that GS010-treated eyes showed a mean improvement of -0.308 LogMAR compared to baseline, equivalent to +15.4 ETDRS letters or three lines on the ETDRS vision chart. This improvement in visual acuity maintains the gain observed at week 72 (+14.7 ETDRS letters equivalent).
BCVA in sham-treated eyes achieved a mean improvement of -0.259 LogMAR over baseline, or a gain of +12.9 ETDRS letters equivalent, at week 96, similar to previous readouts at week 48 and week 72.
As in Rescue, patients experienced an initial point of low visual acuity, or nadir. However, the eyes of Reverse subjects recovered, and GS010-treated eyes had gained 28 more letters relative to their nadir by week 96.
Data from Rescue is expected to be available by the end of the third quarter of 2019.
The trial has also found that bilateral improvement continued in key visual functions BCVA and contrast sensitivity, establishing the safety and tolerability of GS010 over the course of the trial.
Reflect is another multi-centre, randomised, double-masked, placebo-controlled study to evaluate the safety and efficacy of bilateral injections of GS010 in subjects with LHON due to the NADH dehydrogenase 4 (ND4) mutation.
The trial is expected to involve 90 patients with vision loss up to one year in duration and will be conducted at multiple centres in Europe and the US.