AAVantgarde Bio (AAVantgarde), the clinical-stage biotechnology company developing genetic medicines for inherited retinal diseases (IRDs) using its proprietary dual-AAV technology, has announced the presentation of updated clinical data from the LUCE-1 study and preclinical and clinical development data for AAVB-039 for Stargardt disease at the 26^th European Society of Retina Specialists (EURETINA) Annual Congress (EURetina 2026), taking place in Vienna.

Prof. Francesca Simonelli presented preliminary findings from the LUCE-1 Phase 1/2 study (NCT06591793), an open-label study evaluating subretinal administration of AAVB-081, a dual AAV8.MYO7A gene therapy using a DNA-splicing approach, in adults with Usher type B retinitis pigmentosa. Enrollment in LUCE-1 was completed in January 2026, with 15 participants treated across three dose cohorts. The presentation included safety data across all treated participants and efficacy assessments from participants with at least six months of follow-up.

As of the August 3, 2026 data cut-off point, no serious adverse events or dose-limiting toxicities had been reported, and no participants had discontinued the study. Ocular inflammation was limited, in-line with expectations and responsive to corticosteroid treatment.

Among the 12 participants in the low- and mid-dose cohorts with at least six months of follow-up, early signals of visual function improvement were observed. Seven participants achieved at least a one-line improvement in best-corrected visual acuity (BCVA), including four participants with at least a two-line improvement. Six participants achieved at least a one-line improvement in low-luminance visual acuity (LLVA), including four participants with at least a three-line improvement. Exploratory assessments also showed supportive signals in fixation stability and microperimetry in several participants.

The data support continued clinical development of AAVB-081 in USH1B and further evaluation of visual function outcomes with longer follow-up.

Prof. Paulo Eduardo Stanga presented new data supporting the clinical translation of AAVB-039, AAVantgarde's dual AAV8.ABCA4 gene therapy for STGD1. AAVB-039 uses a dual AAV intein-mediated protein trans-splicing approach to deliver the full-length ABCA4 gene to photoreceptors.

Across mouse, pig and non-human primate models, the dual AAV8.ABCA4 approach demonstrated reconstitution of full-length ABCA4 proteins and a reduction of lipofuscin accumulation, together with a favourable ocular safety profile. In a STGD1 pig model, treatment resulted in full-length ABCA4 expression exceeding 100% of endogenous ABCA4 levels in the reported analysis, with reduced lipofuscin accumulation in treated areas compared with sham-injected knockout eyes. In non-human primates, 76–99% of photoreceptors were co-transduced with the two vector components across approximately 60% of the analysed retinal section. Ocular effects were described as mild and transient, with electroretinography changes that were temporary and dose-related and histological findings that were minimal, localized and improved over time.

The AAVB-039 clinical development program comprises the STELLA natural history study, which has completed enrolment of 150 patients, and the CELESTE first-in-human Phase 1/2 study. CELESTE is a phase 1/2 study evaluating the safety and preliminary efficacy of AAVB-039 in participants with STGD1 caused by biallelic pathogenic ABCA4 variants. The study is recruiting in the US, UK and Europe.

Dr. Jayashree Sahni, CEO of AAVantgarde commented: “The data presented at EURetina 2026 provide important updates across both of our lead programs. In LUCE-1, the continued absence of serious adverse events or dose-limiting toxicities, together with early signals of improved visual function in the low- and mid-dose cohorts, support the continued development of AAVB-081 in Usher syndrome type 1B. At the same time, the preclinical data for AAVB-039 demonstrate consistent ABCA4 expression, lipofuscin reduction and favourable ocular safety across relevant large animal models, supporting the ongoing clinical translation of our dual AAV intein platform in Stargardt disease.”