EU/3/14/1283: Orphan designation for the treatment of Stargardt's disease

Stargardt's disease is a genetic (hereditary) disorder of the eye that leads to progressive loss of sight. Stargardt's disease is caused by abnormalities in a gene called ABCA4. The ABCA4 gene is responsible for the production of a protein called ABCR that regulates the transport of substances in and out of some cells in the retina (the light-sensitive surface at the back of the eye). In patients with Stargardt's disease, ABCR does not work properly. This causes deposits to build up inside the retina cells, which become damaged and eventually die.

Stargardt's disease is a long-term debilitating disease because the patient's sight becomes progressively worse and eventually leads to blindness.

At the time of designation, Stargardt's disease affected approximately 1.5 in 10,000 people in the European Union (EU). This was equivalent to a total of around 77,000 people*, and is below the ceiling for orphan designation, which is 5 people in 10,000. This is based on the information provided by the sponsor and the knowledge of the Committee for Orphan Medicinal Products (COMP).

*Disclaimer: For the purpose of the designation, the number of patients affected by the condition is estimated and assessed on the basis of data from the European Union (EU 28), Norway, Iceland and Liechtenstein.
At the time of designation, this represented a population of 512,900,000 (Eurostat 2014).

At the time of designation, no satisfactory methods were authorised in the EU for the treatment of Stargardt's disease.

This medicine is made of two viruses, each containing half of the normal human ABCA4 gene as the gene is too large to be contained within one virus. When injected into the eye of patients with Stargardt's disease, it is expected that the viruses will carry the two halves of the ABCA4 gene into the cells of the retina, where these two halves are expected to re-assemble into the normal ABCA4 gene. The retina cells are then expected to produce normal ABCR protein, thereby relieving the symptoms of the disease and preventing loss of sight.

The type of virus used in this medicine (adeno-associated virus) does not cause disease in humans.

The effects of the medicine have been evaluated in experimental models.

At the time of submission of the application for orphan designation, no clinical trials with the medicine in patients with Stargardt's disease had been started.

At the time of submission, the medicine was not authorised anywhere in the EU for Stargardt's disease or designated as an orphan medicinal product elsewhere for this condition.

In accordance with Regulation (EC) No 141/2000 of 16 December 1999, the COMP adopted a positive opinion on 14 May 2014 recommending the granting of this designation.

• the seriousness of the condition;
• the existence of alternative methods of diagnosis, prevention or treatment;
• either the rarity of the condition (affecting not more than 5 in 10,000 people in the EU) or insufficient returns on investment.

Designated orphan medicinal products are products that are still under investigation and are considered for orphan designation on the basis of potential activity. An orphan designation is not a marketing authorisation. As a consequence, demonstration of quality, safety and efficacy is necessary before a product can be granted a marketing authorisation.