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 legally blind at birth due to biallelic AIPL1 mutations, with rapid retinal degeneration by age four if untreated.

• The first cohort of 4 received unilateral treatment; the second cohort of 7 received bilateral sequential therapy.

Study design and treatment approach

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

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

Efficacy and clinical outcomes

• All 11 children showed unequivocal, durable improvement in visual function, visual acuity, and visual behavior, with some gaining the ability to see for the first time.

• 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.

• Treated eyes demonstrated preserved retinal structure and thickness, confirmed by OCT and EEG/visual evoked potentials.

• Functional gains included object identification, navigation, and improved communication, schooling, mood, and social integration.

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