Biopharmaceutical company GenSight Biologics (Euronext: SIGHT) on Wednesday announced final efficacy and safety results from the REFLECT Phase III trial for LUMEVOQ (GS010; lenadogene nolparvovec), confirming sustained visual acuity improvement and a strong safety profile five years post-treatment in patients with Leber Hereditary Optic Neuropathy (LHON).

Patients who received bilateral treatment demonstrated superior outcomes, with 75% achieving clinically relevant recovery compared to 60% in the unilateral group. Average visual acuity in treated eyes improved beyond the +15-letter threshold (-0.3 LogMAR change) from nadir, underscoring the therapy's effectiveness. On-chart vision was observed in 79% of bilaterally treated patients versus 72% in the unilateral group.

No serious ocular adverse events or treatment-related study discontinuations were reported. The primary safety concern, mild intraocular inflammation, was effectively managed with standard treatment.

REFLECT was a randomised, double-masked, placebo-controlled Phase III study involving 98 LHON patients with the ND4 mutation, conducted across Europe, the UK, the US and Taiwan. Each participant received LUMEVOQ in the first affected eye, with the second eye randomised to receive either LUMEVOQ or a placebo. The trial followed patients for five years post-injection.

GenSight Biologics specializes in developing gene therapies for retinal neurodegenerative diseases and central nervous system disorders. LUMEVOQ, based on proprietary mitochondrial targeting sequence (MTS) technology, aims to restore mitochondrial function in LHON patients. While not yet approved for market, the therapy has shown consistent efficacy across multiple trials.

Long-term follow-up concluded on 23 July 2024, reinforcing LUMEVOQ's potential as a breakthrough treatment for LHON.