Researchers Start New Clinical Trial for the Treatment of Genetic Blindness

OXFORD, 22-Mar-2017 — /EuropaWire/ — Researchers have started a new gene therapy clinical trial to treat X-linked retinitis pigmentosa (XLRP), the most common cause of blindness in young people. Retinitis pigmentosa is currently untreatable and leads to a slow and irreversible loss of vision.

The trial is being run by Nightstarx Ltd (Nightstar), a biopharmaceutical spinout company of Oxford developing gene therapies for inherited retinal diseases, and researchers from the University of Oxford. On 16 March 2017, a 29 year old British man became the first patient with X-linked retinitis pigmentosa to undergo gene therapy. The operation took place at the Oxford Eye Hospital, part of the Oxford University Hospitals NHS Foundation Trust.

Gene therapy uses a virus to insert the correct copy of a defective gene into cells, and has shown promise for treating genetic causes of blindness. Unfortunately, the gene involved with retinitis pigmentosa, RPGR, is highly unstable, making gene therapy particularly challenging. The RPGR gene’s unusual genetic code has made it very difficult to work with in the laboratory.

However, a research team led by Professor Robert MacLaren from the University of Oxford has reprogrammed the genetic code of RPGR to make it more stable, but in a way that does not affect its function. This has allowed the gene to be delivered reliably by a viral vector into retinal cells.

The current trial is the first in the world to test a treatment for retinitis pigmentosa caused by RPGR.

Robert MacLaren, Professor of Ophthalmology at the University of Oxford, who is leading the trial said, “The effect of RPGR-related disease on families with retinitis pigmentosa is devastating and we have spent many years working out how to develop this gene therapy. Changing the genetic code is always undertaken with great caution, but the new sequence we are using has proven to be highly effective in our laboratory studies.

“The genetic code for all life on Earth is made up of four letters – G, T, A and C. In RPGR, however, half of the gene comprises only two letters – A and G. This makes the gene very unstable and prone to mutations, making it a lead cause of blindness in patients with retinitis pigmentosa. RPGR is vital for the light sensitive cells at the back of the eye.”

The trial has started at the Oxford University Hospitals NHS Foundation Trust and is sponsored by Nightstar, a University of Oxford spin-out company. It is supported by the NIHR Biomedical Research Centre at the Oxford University Hospitals NHS Foundation Trust. Up to 30 patients will be enrolled.

David Fellows, Chief Executive Officer of Nightstar remarked, “We are delighted to report the advancement of this exciting gene therapy program into patients. If successful, this gene therapy has the potential to transform the lives of many patients (and their families) around the world.”

Dr Aniz Girach, Chief Medical Officer of Nightstar commented, “The current trial is an open-label dose-escalation study designed to enrol at least 24 patients who will receive a single subretinal injection of the RPGR gene therapy. The primary goal of the study is to assess safety and tolerability of this gene therapy over a 12 month period.”

For further information, please contact Chris McIntyre in the University of Oxford press office at or on+44 (0)1865 270 046.

Notes to editors:

Images of Professor Robert MacLaren’s work can be downloaded here: (credit: OUH Trust).

Oxford University Hospitals NHS Foundation Trust (OUH) is one of the largest acute teaching trusts in the UK, with a national and international reputation for the excellence of its services and its role in patient care, teaching and research. The Trust supports world-leading research programmes in cardiovascular diseases, musculoskeletal disorders, neurological disorders such as Parkinson’s and Alzheimer’s through its designation as one of the UK’s five comprehensive biomedical centres. It works in close partnership with the University of Oxford and is a leading centre for cancer, neurosciences, diabetes, genetics and many other fields. Research themes of particular strength are: cancer, cardiovascular science, diabetes, endocrinology & metabolism, infection and immunology, musculoskeletal science, neuroscience and reproduction and development.

This brings together academic research expertise with clinical teams to translate medical science into better healthcare treatments. Our patients benefit from world-class discovery and innovation supported by the NIHR Oxford Biomedical Research Centre, a partnership between the Trust and the University of Oxford, funded by the National Institute for Health Research (NIHR).
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The National Institute for Health Research (NIHR) is funded by the Department of Health to improve the health and wealth of the nation through research. The NIHR is the research arm of the NHS. Since its establishment in April 2006, the NIHR has transformed research in the NHS. It has increased the volume of applied health research for the benefit of patients and the public, driven faster translation of basic science discoveries into tangible benefits for patients and the economy, and developed and supported the people who conduct and contribute to applied health research. The NIHR plays a key role in the Government’s strategy for economic growth, attracting investment by the life-sciences industries through its world-class infrastructure for health research. Together, the NIHR people, programmes, centres of excellence and systems represent the most integrated health research system in the world. For further information, visit the NIHR website (

SOURCE: University of Oxford

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