EU/3/14/1282: Orphan designation for the treatment of Usher syndrome

Usher syndrome is a hereditary (genetic) disease that affects hearing, vision and balance. There are three types of the disease, and the extent of the problems with hearing, vision and balance varies depending on the type. Hearing loss usually occurs from birth, while loss of sight usually develops gradually over time and is caused by the degeneration of the cells in the retina (a condition known as retinitis pigmentosa).

Usher syndrome is a long-term debilitating condition because it can lead to deafness, blindness and balance problems.

At the time of designation, Usher syndrome affected less than 1 in 10,000 people in the European Union (EU). This was equivalent to a total of fewer than 51,000 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 treating Usher syndrome. Patients with the condition were given hearing aids and general support.

Usher syndrome subtype IB is mainly caused by defects in a gene called myosin 7A (MYO7A), which is important for the normal functioning of the cells of the inner ear and the retina.

This medicine is made of two viruses, each containing half of the normal human MYO7A gene as the gene is too large to be contained within one virus. When injected into the eye of patients with Usher syndrome subtype IB, it is expected that the viruses will carry the two halves of the MYO7A gene into the cells of the retina, where these two halves are expected to re-assemble into the normal MYO7A gene. The retina cells are then expected to function properly, thereby 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 Usher syndrome had been started.

At the time of submission, the medicine was not authorised anywhere in the EU for Usher syndrome 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.