First gene therapy for inherited retinal disease takes a step closer to European approval

Posted on: Sunday 23 September 2018

The European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) has recommended approval of the gene therapy Luxterna for the treatment of inherited retinal dystrophy caused by mutations in the RPE65 gene. A final marketing authorisation decision from the European Commission is expected in around two months’ time. This will be followed by significant discussions at national level to determine pricing and patients’ access to the treatment.

The RPE65 gene provides instructions for building an enzyme that is critical for recycling the substances that convert light into electrical signals at the back of the eye. If this enzyme is reduced or absent because of genetic mutations, the visual cycle is blocked, resulting in impaired vision and the accumulation of toxins.

Vision loss often starts during childhood or adolescence and progresses as retinal cells degenerate. Fifty percent of people with mutations in both their copies of the RPE65 gene (one copy is inherited from each parent) will experience severe sight loss by the time they are 16 years old.

The CHMP has recommended approval of Luxterna for patients who have two mutated copies of RPE65 and still have sufficient viable retinal cells, as determined by a healthcare professional, to benefit from the therapy. Luxterna works by delivering healthy, functional copies of the RPE65 gene, via a single retinal injection, to restore levels of the enzyme and allow the visual cycle to progress normally. As demonstrated in clinical trials, this can prevent further vision loss and can restore some functional vision; patients treated with Luxturna showed significantly improved night vision one year after treatment.

Safety monitoring to continue
The most common side effects reported during clinical trials of Luxterna were eye redness, cataracts and increased ocular pressure. Although the CHMP’s recommendation is based on a thorough review of the scientific data and a careful risk-benefit analysis, it does require long term follow up of treated patients to ensure continued safety and efficacy. This is particularly important with a treatment as novel as gene therapy; if approved, Luxterna will be the first and only gene therapy available in Europe to treat inherited retinal disease.

“The CHMP’s positive opinion on Luxterna represents a significant milestone, not only for those living with RPE65 mutations, but also for the thousands of UK families affected by other types of inherited retinal disease who could eventually benefit from gene therapy” said Tina Houlihan, Chief Executive of RP Fighting Blindness. “Luxterna gives huge hope to our community as a whole.”

About the manufacturer
Luxterna was developed and is made by US-based Spark Therapeutics but, if approved in Europe, would be marketed here by Novartis.