MeiraGTx (MGTX) Study Update summary

Study background and patient population

• Eleven children aged 1–4 years with AIPL1-associated LCA4, a severe congenital blindness, were treated with rAAV8.hRKp.AIPL1 gene therapy under a UK MHRA 'Specials' license.

• All children were born legally blind due to biallelic AIPL1 mutations, with rapid retinal degeneration by age four if untreated.

• The first cohort of four received unilateral treatment; the second cohort of seven received bilateral sequential therapy.

• Patients were recruited globally, including from the UK, US, Turkey, Tunisia, New Zealand, Australia, and Thailand.

• The first four patients' data were published in The Lancet.

Study design and treatment approach

• rAAV8.hRKp.AIPL1 delivers wild-type human AIPL1 under a photoreceptor-specific promoter via subretinal injection.

• Designed as a one-time administration to restore vision in children with LCA4.

• Open-label, first-in-human interventional study.

Efficacy and clinical outcomes

• All 11 treated children showed unequivocal, durable improvements in visual function, acuity, and behavior, with previously blind children now able to see.

• Visual acuity improved to a mean of 0.9 LogMAR in the unilateral group and 1.0 LogMAR in the bilateral group, with best acuity at 0.6 LogMAR.

• Objective evidence included improved visual behavior, reduced nystagmus, EEG/visual evoked potentials, and preserved retinal structure by OCT.

• Improvements were observed as early as four weeks post-treatment and were durable up to four years in the first cohort.

• Treatment outcomes surpass those of any approved or published ocular gene therapy for inherited retinal diseases.