The Clinical Trial

The clinical trial that has just begun at the Oxford Eye Hospital, represents the world's first ever attempt to treat choroideremia and the first time that gene therapy has been directed towards the light sensitive photoreceptor cells of the human retina. Patients in the trial will have a virus injected into their eye which has been genetically engineered to carry a missing gene. The virus has been modified to enable it to infect the light sensitive cells known as photoreceptors that line the back of the eye. Mr Jonathan Wyatt a 62 year old man from Bristol was, this week, the first patient to undergo this pioneering surgery. There are 12 patients enrolled in the trial who will undergo gene surgery treatment to one eye. It is estimated to take a further 24 months to know whether or not the degeneration has been stopped completely by the gene therapy treatment.

 

This is the first time these cells have been targeted using gene therapy and it paves the way for the treatment of other genetic causes of blindness such as retinitis pigmentosa.

 

The trial is being led by Professor Robert MacLaren, Professor of Ophthalmology at the University of Oxford and builds on gene therapy research performed in collaboration with Professor Miguel Seabra at Imperial College London. Professor MacLaren said, "This disease has been recognised around the world as an incurable form of blindness for over a hundred years. I cannot describe the excitement in thinking that we have designed a genetic treatment that could potentially stop it in its tracks with one single injection."

 

Professor Seabra, who played a key role at Imperial College London in identifying the gene causing choroideremia and in eliciting the mechanism of cell death in the retina comments: "The ability to offer a gene replacement treatment for these patients was the final objective of 20 years of intense research in my laboratory. This is a moment of fulfilment for us and a dream come true for all choroideremia patients."

 

Fight for Sight involvement

 

Fight for Sight through the Tommy Salisbury Choroideremia Fund have been supporting Professor Seabra's research into choroideremia at Imperial College London over the past five years. This support has been vital in taking the research to this stage. Professor Robert MacLaren said "This clinical trial marks a major step in developing gene therapy treatments for photoreceptor diseases. It would not have been possible however without the scientific funding provided by Fight for Sight through the Tommy Salisbury Choroideremia Fund over the last five years. In my opinion, this is the single most significant factor that has enabled our British team of researchers to lead the world in starting the first clinical trial for this disease. We should not under-estimate the power that individuals can have in influencing the course of research through their fundraising activities."