15th February 2026- A patient in Oxford has been treated for Stargardt disease as part of a Phase II clinical trial led by genetic medicines company SpliceBio. The milestone marks the beginning of the trial’s second phase evaluating a novel gene therapy for the inherited retinal disorder.
Stargardt disease, caused by mutations in the ABCA4 gene, leads to progressive vision loss and is the most common inherited form of juvenile macular degeneration. The condition affects up to 1 in 8,000 people worldwide and currently has no approved treatment.
SpliceBio’s investigational therapy uses a dual-vector gene delivery system—two harmless viral vectors that recombine inside retinal cells to restore the full-length ABCA4 gene. The large size of the gene has historically prevented replacement using conventional single-vector gene therapy approaches.
Dr. Robert MacLaren, Professor of Ophthalmology at the University of Oxford, highlighted the significance of the approach: dual-vector recombination may not only address Stargardt disease but could also have broader implications for other inherited retinal degenerations.
Patient advocacy groups welcomed the development. Retina UK described the trial as “highly innovative,” noting the profound life impact of progressive sight loss in children and young adults. Community organization Stargardt’s Connected similarly expressed optimism regarding emerging treatment options.
In June 2025, SpliceBio secured $135 million in financing, co-led by EQT Life Sciences and Sanofi Ventures, with participation from Roche Venture Fund. The funding supports continued clinical development.
The Phase II trial aims to enroll 57 patients aged 12 to 65 and is expected to conclude in 2028. If successful, the therapy could represent a transformative advance for individuals living with this currently incurable inherited condition.
