A patient in Oxford has been treated for a degenerative eye condition as part of a new clinical trial by the genetic medicines company SpliceBio. The trial is testing a new gene therapy for Stargardt disease, a currently incurable inherited eye condition which leads to progressive vision loss and eventually blindness in children and adults. The condition affects up to 1 in 8,000 people worldwide. The patient in Oxford represents the start of the trial’s second phase.
Retina UK, a charity which supports people with inherited sight loss, told Cherwell: “Stargardt disease is most commonly diagnosed in children and young people and causes progressive sight loss that impacts every part of life, from education and careers to leisure and relationships.”
A young person who has been living with Stargardt disease for ten years told Cherwell: “ A progressive eye condition means I do not know when my eyesight will dip and having to adapt again after loss of vision is very emotionally challenging for me and my family. Knowing that there is no current treatment or cure also has an impact on my family emotionally.”
The disease is caused by a mutation of the ABCA4 gene. SpliceBio’s therapy uses two harmless viruses to deliver a healthy version of the gene into the retina. Until this trial, the large size of the ABCA4 gene had made it impossible to replace using standard gene therapy methods. SpliceBio states that their gene therapy has the “potential to treat all patients across all ABCA4 mutations”.
SpliceBio secured $135 million in financing in June 2025, co-led by EQT Life Sciences and Sanofi Ventures with participation from Roche Venture Fund, as well as previous investors. EQT Life Sciences is one of Europe’s largest life sciences investors. Sanofi Ventures are investors in the early life biotech and digital health industries.
Dr Robert MacLaren, Professor of Ophthalmology at the University of Oxford, said: “The use of two viral vectors that recombine once inside retinal cells is a unique approach to restoring the large gene needed in Stargardt disease, and dual vectors might have implications for treating other retinal degenerations. This unique gene therapy modality has the potential to slow or even halt progression of this debilitating disease, which is the most common cause of inherited blindness in children. We are delighted to have treated the first patient here in Oxford, in the critical second phase of the trial.”
A representative from Retina UK told Cherwell: “Any progress in this research is exciting, particularly a clinical trial of a highly innovative approach such as SpliceBio’s. Our community would welcome treatments that have the potential to significantly slow or even stop disease progression.”
A representative from Stargardt’s Connected, a charity which supports and connects those living with Stargardt disease, told Cherwell: “The Stargardt’s Community is very excited about latest research and developments in Stargardt’s, in particular that there are companies looking into a treatment for Stargardt’s Disease.”
The second phase of the clinical trial aims to treat 57 patients aged 12 to 65, and is predicted to conclude in 2028.
