, The state of gene therapy and stem cell treatment for blindness

The state of gene therapy and stem cell treatment for blindness

Many people in the visually impaired community are (understandably) excited about the prospect of using gene therapy and stem cells to potentially cure blindness.

While there have been encouraging developments in these fields, on the whole it is still early stages.

In December 2017, the U.S. Food and Drug Administration (FDA) approved the clinical use of voretigene neparvovec (Luxturna), the first gene therapy for any condition to be given the go ahead. This comes off the back of over 10 years of research and clinical trials, and is aimed at only those with an “inherited retinal disease caused by mutations in both copies of the RPE65 gene and who have enough remaining cells in the retina”.

There are more than 250 genes involved in the development of blindness.

When it comes to stem cells, there have been two well publicised trials involving patients with different forms of Age-Related Macular Degeneration (AMD). While the results were promising, the sample sizes were very small (7 in total) and they had only undergone the first phase of trials. 

Generally it may take at least 3 trials before being submitted for approval by governing bodies. So while some may claim that these “could lead to an ‘off-the-shelf’ treatment within five years”, the timeframe makes this extremely optimistic. 

In an analysis by the National Health Service (NHS), they concluded that the 2018 results from the stem cell trials conducted by University College London, Moorfields Eye Hospital and Pfizer were “in its very early stages – bigger longer term trials will be needed to be sure it’s safe and effective”. For context, the phase I trials took three years and only included two patients. Unfortunately, there has not been any more updates since.

One of the more recent trials comes from UK-based biotech company ReNeuron Group. They had started Phase I/IIa clinical trials in the US with their human retinal progenitor cell (hRPC) therapy candidate for retinitis pigmentosa (RP) earlier this year and presented some of their early findings at the sixth annual Retinal Cell and Gene Therapy Innovation Summit in Vancouver, Canada, on the 26th April.

And while progress made has been encouraging, the trials have only been conducted with three people for less than half a year each. 

With number of hurdles needed to be overcome, one can only speculate when these treatments will successfully come to market, if at all. 

On the other hand, technology has seen tremendous growth and plays an ever increasing role in aiding those with a visual impairment. From wearables to apps, accessories to services, there are many potential solutions out there that are able to bridge the gap until a permanent solution is found.