GenSight Biologics has reported further results from its REVERSE Phase III clinical trial for the treatment of Leber hereditary optic neuropathy (LHON).

The trial analyses the safety and efficacy of a single intravitreal injection of GS010 (rAAV2/2-ND4) in 37 subjects suffering with visual loss due to 11778-ND4 LHON.

At 72 weeks, the study observed an improvement from baseline in mean visual acuity in eyes treated with GS010. Concomitant contralateral improvement was found to be of +12 letters (-0.246 LogMAR) in sham-treated eyes.

These results extend the positive trend reported at 48 weeks, indicating a sustained outcome for the trial patients.

An improvement was also seen in contrast sensitivity, as per the Pelli-Robson low-contrast testing.

In week 72, GS010-treated eyes gained on average +0.21 LogCS versus baseline, while sham-treated eyes had seen +0.15 LogCS.

“We’re seeing visual function continue to improve one and a half years after eyes are treated with GS010.”

The proportion of treated eyes that experienced a clinical improvement of at least 0.3 LogCS (45.9%) was statistically higher than that of the sham-treated eyes (24.3%).

The outcome for visual function was also complemented by evidence that GS010 was engaging its anatomic targets, the ganglion cells.

High-resolution Spectral-Domain Optical Coherence Tomography (SD-OCT) demonstrated preservation of the retina anatomy at 72 weeks.

The ganglion cell layer macular volume was preserved in treated eyes, while it deteriorated in sham-treated eyes from baseline.

Drug-treated eyes also indicated a reduced loss in thickness of the temporal quadrant of the retinal fiber layer of -1.6µm, as against a loss of -3.6µm in sham-treated eyes.

GenSight co-founder and CEO Bernard Gilly said: “We’re seeing visual function continue to improve one and a half years after eyes are treated with GS010, and at the same time, objective tests continue to establish neuroprotection of the retina in treated eyes. This is, beyond any doubt, a great benefit for patients and their families.”

“These results strengthen our determination to work with regulatory agencies to bring GS010 to market within our defined timelines.”