Choroideremia Clinical Trial

January 2014 saw the publication of promising clinical trial data from the University of Oxford for a gene therapy for the inherited retinal degeneration, choroideremia.

This experimental gene therapy has been developed by a team led by Professor Robert MacLaren in the University of Oxford in the UK. The gene therapy uses a small, safe virus to deliver the correct version of the CHM gene into the light-sensing photoreceptor cells in the retina. In an operation similar to cataract surgery, the patient’s retina is first detached and then the virus is injected underneath using a very fine needle.

The recent data from the ongoing clinical trial followed six patients for six months after treatment. The patients were a mixture of men with early stage and advanced choroideremia and treatment was in one eye to compare treated eye to untreated eye. After six months, the men with early stage choroideremia did not see any deterioration of their vision in their treated eye, and they will be followed up to see if this vision can be maintained.  However, in the two men who had advanced choroideremia, the treatment has thus far surpassed expectations and these two men have gained two lines and four lines of vision on the eye chart. It is still early days for this trial, and monitoring the safety of this technology, as well as its effectiveness, will be the priority for the researchers over the coming years.

This trial data is very encouraging for Irish people with inherited retinal degenerations. This is the first gene therapy that targets a gene expressed in the light sensing photoreceptor cells in the retina. It is also the first trial to have treated individuals who still have good vision. It therefore shows the potential of this type of therapy to be useful for other conditions such as retinitis pigmentosa and the dry form of age-related macular degeneration and could potentially be used as an early intervention to arrest vision loss.

For more information about this project or any other research, please contact our Research Officer Maria Meehan atmaria.meehan@fightingblindness.ie or 01-6789 004