Gensight has revealed some promising data for its gene therapy GS010, which is currently in testing to treat those with Leber hereditary optic neuropathy (LHON), a rare disease that leads to irreversible blindness.
Gensight’s lead candidate could very well have the potential to change that however, with its recent results propelling forward the biopharma’s aim of offering patients a sustainable functional visual recovery.
Aptly called the REVERSE trial, the phase 3 study evaluated the safety and efficacy of a single intravitreal injection of GS010 in 37 patients, whose visual loss started between 6 and 12 months prior to the study.
Participants of the study were tested against Logarithm of the Minimal Angle of Resolution scores, which are derived from the number of letters patients read on the ETDRS chart.
At 72 weeks, a clinically meaningful improvement from baseline in mean visual acuity of +15 letters was observed in GS010-treated eyes, with associated contralateral improvement of +12 letters in sham-treated eyes.
Continued improvements were also seen in contrast sensitivity, with 45.9% achieving at least 0.3 LogCS compared to 24.3% of sham-treated eyes.
“The level of sustained improvement in both visual acuity and low-contrast sensitivity, and the sustained preservation of retinal ganglion cells on OCT, at this stage of disease progression is very encouraging, and is a departure from what has been observed and reported on the natural history of LHON,” said Mark Moster, Neuro-Ophthalmology, Wills Eye Hospital and Principal Investigator in REVERSE and RESCUE trials.
The candidate is on its way to achieving the primary endpoint, a prospect that seemed dimming after disappointing data from week 48.
Gensight’s Bernard Gilly
All 37 subjects involved in the study will be further evaluated at week 96, with final data expected in Q2.
Bernard Gilly, Co-founder and Chief Executive Officer of GenSight, 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.”
The treatment uses GenSight’s propiteary mitochondrial targeting sequence (MTS) technology, which specifically targets defects inside the mitochondria using an AAV vector.
If approved, the gene therapy would compete with Santhera’s Raxone, which became the first approved treatment for LHON in Europe in 2015.
The gene of interest is transferred into the cell to produce the functional protein, which will then be shuttled to the mitochondria through specific nucleotidic sequences to restore the missing or deficient mitochondrial function.
GenSight isn’t the only player leveraging gene therapy to improve eyesight. Just last month, the EMA’s advisory committee gave the all clear to Spark’s Luxturna to treat adults and children suffering from inherited retinal dystrophy.
Luxturna, was the first ever gene therapy to be approved for any form of genetic blindness in the US, and now it’s edging closer to that all important European approval.
UK biotech startup Nightstar is also making waves in this space, bagging a fast-track status for its choroideremia gene therapy in the US.