EU/3/03/169

On 20 October 2003, orphan designation (EU/3/03/169) was granted by the European Commission to Orfagen, France, for human immunoglobulin for the treatment of dermatomyositis.

What is dermatomyositis?

Dermatomyositis is a disease involving the muscles and the skin. The typical sign of dermatomyositis is progressive weakness of the muscles of the upper part of the legs or arms. In the course of the disease also the muscles of the oesophagus, the respiratory system and the heart can be affected so that the patients have difficulties in eating and breathing. The disease is also associated with characteristic severe symptoms in the skin. Patients affected by dermatomyositis have a higher risk of developing cancer and should be accurately examined on a regular basis.

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

At the time of designation, dermatomyositis affected less than 1.25 in 10,000 people in the European Union (EU)*. This is equivalent to a total of fewer than 48,000 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: The number of patients affected by the condition is estimated and assessed for the purpose of the designation, for a European Community population of 385,000,000 (Eurostat 2002) and may differ from the true number of patients affected by the condition. This estimate is based on available information and calculations presented by the sponsor at the time of the application.

What treatments are available?

Several products including glucocorticoids and azathioprine were authorised for the condition in some countries in the Community at the time of submission of the application for orphan drug designation. Human immunoglobulin is expected to be of potential significant benefit in particular in patients not responding to or not tolerating the standard treatments. The assumption will have to be confirmed at the time of marketing authorisation. This will be necessary to maintain the orphan status.

How is this medicine expected to work?

Although the exact cause of the disease remains unknown, it seems that the immune system of the patient is directly involved. The patient’s immune system seems, in fact, to react against some natural body elements. The human immunoglobulin mechanism of action is complex. It seems to interfere with the immune system and decrease the immune reactions against body elements.

What is the stage of development of this medicine?

Human immunoglobulin is used in the treatment of dermatomyositis since several years. Case reports and results from small clinical trials on the use of human immunoglobulin in dermatomyositis have been published in the literature.

At the time of submission of the application for orphan designation, no clinical trials in patients with the condition were ongoing.

The proposed medicinal product is not authorised in any country in the designated indication, but it is authorised in the Community for the treatment of immunoglobuline deficiency and some autoimmune diseases. It was designated for treatment of dermatomyositis and polymyositis in the United States in October 1993.

In accordance with Regulation (EC) No 141/2000 of 16 December 1999, the COMP adopted a positive opinion on 10 September 2003 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.

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