EU/3/14/1278 - orphan designation for treatment of choroideraemia

adeno-associated viral vector serotype 2 containing the human CHM gene encoding human Rab escort protein 1

Overview

On 4 June 2014, orphan designation (EU/3/14/1278) was granted by the European Commission to Alan Boyd Consultants Ltd, United Kingdom, for adeno-associated viral vector serotype 2 containing the human CHM gene encoding human Rab escort protein 1 for the treatment of choroideremia.

What is choroideremia?

Choroideremia is a hereditary disease of the eye that leads to progressive loss of sight. The disease mostly affects males. In patients with choroideremia, cells in the retina (the light-sensitive surface at the back of the eye), the retinal pigment epithelium (the cell layer just outside the retina that nourishes retinal cells) and the choroid (a network of blood vessels located between the retina and the sclera, the “white of the eye”) become damaged and eventually die.

Chodoideraemia is a long-term debilitating disease because it causes the patient's sight to worsen, eventually leading to blindness.

What is the estimated number of patients affected by the condition?

At the time of designation, choroideremia affected less than 0.2 people in 10,000 per year in the European Union (EU). This was equivalent to fewer than 10,000 people per year*, and is below the ceiling for orphan designation. This is based on the information provided by the sponsor and the knowledge of the Committee for Orphan Medicinal Products (COMP).

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*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. This represents a population of 511,100,000 (Eurostat 2014).

What treatments are available?

At the time of designation, no satisfactory methods were authorised in the EU to treat choroideremia. Vitamins, supplements and a healthy diet were often used to manage the disease. Patients were advised to use sunglasses in very sunny conditions. Patients with choroideremia usually received genetic counselling on the risks of passing the condition on to their children, and regular medical follow up.

How is this medicine expected to work?

Choroideremia is caused by a defect in the CHM gene, which is responsible for the production of a protein called 'Rab escort protein 1'. This protein has a key role in the correct functioning of the cells of the eye.

This medicine is made of a virus that contains a normal copy of the CHM gene. It is expected that when injected into the patient's eye the virus will carry the CHM gene into the cells of the eye, enabling them to function normally and thereby helping to improve the patient's sight.

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

What is the stage of development of this medicine?

At the time of submission of the application for orphan designation, the evaluation of the effects of the medicine in experimental models was ongoing.

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

At the time of submission, the medicine was not authorised anywhere in the EU for choroideraemia. Orphan designation has been granted in the United States for 'treatment of choroideremia due to mutations in the human choroideremia gene'.

In accordance with Regulation (EC) No 141/2000 of 16 December 1999, the COMP adopted a positive opinion on 9 April 2014 recommending the granting of this designation.

Opinions on orphan medicinal product designations are based on the following three criteria:

• 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.

EU/3/14/1278: Public summary of opinion on orphan designation of adeno-associated viral vector serotype 2 containing the human CHM gene encoding human Rab escort protein 1 for the treatment of choroideraemia

Adopted Reference Number: EMA/COMP/223562/2014 Rev.1

Key facts

• Active substance:
  adeno-associated viral vector serotype 2 containing the human CHM gene encoding human Rab escort protein 1
• Intended use:
  Treatment of choroideraemia
• Orphan designation status:
  Positive
• EU designation number:
  EU/3/14/1278
• Date of designation:
  04/06/2014
• Sponsor:

  France Choroideremie