Biopharma company GenSight Biologics has reported the first results of a single intravitreal injection of GS010 at 96 weeks in the company’s RESCUE Phase III clinical trial.

GS010 is designed to target Leber hereditary optic neuropathy (LHON), a rare maternally inherited mitochondrial genetic disease.

LHON is a ‘symmetric disease with poor functional visual recovery’ affecting adolescents and young adults.

The drug candidate is also being evaluated in a separate randomised, double-masked, sham-controlled Phase III trial called REVERSE.

In both trials, GS010 is administered to participants suffering from LHON due to the G11778A mutation in the mitochondrial ND4 gene.

During the RESCUE Phase III clinical trial, 39 subjects with visual loss due to 11778-ND4 LHON were assessed.

The results showed sustained efficacy and safety at 96 weeks in the trial. The safety data’s preliminary analysis revealed that GS010 was well-tolerated after 96 weeks.

RESCUE and REVERSE trials Principal Investigator Dr Mark L Moster said: “The results from the RESCUE study are encouraging and convincing, particularly because we are seeing a similar pattern to the REVERSE study results.

“Patients in RESCUE were treated before the nadir so, as expected, they continued to worsen early on. But then from week 48 until week 96, they experienced a recovery from the nadir. That is much better than the natural history in any prior studies.”

The company has plans to submit a marketing approval application in Europe in the third quarter of next year.

It is also expected to participate in an end of Phase II meeting with the US Food and Drug Administration (FDA) in November. The company is also planning to arrange a pre-submission meeting with the European Medicines Agency in early 2020.