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Orphan designation

On 12 March 2013, orphan designation (EU/3/13/1116) was granted by the European Commission to Glaxo Group Ltd, United Kingdom, for mepolizumab for the treatment of Churg-Strauss syndrome.

What is Churg-Strauss syndrome?

Churg-Strauss syndrome is a type of vasculitis (a chronic inflammation of small to medium-sized arteries and veins). The causes of the disease are not known but it is characterised by fever, hypereosinophilia (abnormally high production of a type of white blood cells called eosinophils) and granulomatosis (clumping of eosinophils into small granular lumps that result in inflammation). Other symptoms of the disease include asthma and sinus problems, numbness or pain in the extremities, and inflammation of organs, including the lungs, heart, kidneys and gut.

Churg-Strauss syndrome is a long-term debilitating and life-threatening condition due to the inflammation of the organs. The main causes of death are myocarditis (inflammation of the heart muscle) and myocardial infarction (heart attack) following coronary arteritis (inflammation of the coronary arteries).

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

At the time of designation, Churg-Strauss syndrome affected not more than 0.5 in 10,000 people in the European Union (EU). This was equivalent to a total of not more than 25,000 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 27), Norway, Iceland and Liechtenstein. This represents a population of 509,000,000 (Eurostat 2013).

What treatments are available?

At the time of orphan designation there were no satisfactory treatments authorised in the EU for Churg-Strauss syndrome. The symptoms of milder forms of the disease were usually treated with anti-inflammatory medicines called corticosteroids.

How is this medicine expected to work?

Mepolizumab is a monoclonal antibody (a type of protein) that has been designed to recognise and attach to a specific protein found in the body called interleukin-5 (IL-5). IL-5 promotes the production and growth of eosinophils. By attaching to it, mepolizumab is expected to stop it working, reducing the production and survival of eosinophils. As eosinophils are the cells that are involved in causing Churg-Strauss syndrome, this is expected to improve the symptoms of the disease.

What is the stage of development of this medicine?

The effects of mepolizumab have been evaluated in experimental models.

At the time of submission of the application for orphan designation, no clinical trials with mepolizumab in patients with Churg-Strauss syndrome were ongoing.

At the time of submission, mepolizumab was not authorised anywhere in the EU for Churg-Strauss syndrome. Orphan designation of mepolizumab had been granted in the United States for Churg-Strauss syndrome. Orphan designation had also been obtained in the EU for hypereosinophilic syndrome.

In accordance with Regulation (EC) No 141/2000 of 16 December 1999, the COMP adopted a positive opinion on 6 February 2013 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.

Key facts

Product details for <p>Mepolizumab</p>
Active substanceMepolizumab
Medicine Name
Disease/conditionTreatment of Churg-Strauss syndrome
Date of decision12/03/2013
Orphan decision numberEU/3/13/1116

Review of designation

The Committee for Orphan Medicinal Products reviews the orphan designation of a product if it is approved for marketing authorisation.

Sponsor's contact details:

Glaxo Group Limited
Glaxo Wellcome House
Berkeley Avenue
United Kingdom
Tel. +44 (0)20 8990 2311
Fax +44 (0)20 8990 3501

Patients' organisations:

For contact details of patients’ organisations whose activities are targeted at rare diseases see:

  • Orphanet, a database containing information on rare diseases which includes a directory of patients’ organisations registered in Europe.
  • European Organisation for Rare Diseases (EURORDIS), a non-governmental alliance of patient organisations and individuals active in the field of rare diseases.