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Orphan designation

On 1 April 2008, orphan designation (EU/3/08/531) was granted by the European Commission to Murigenetics SAS, France, for ascorbic acid for the treatment of Charcot-Marie-Tooth disease type 1A.

For a list of the administrative updates to this public summary of opinion please refer to the PDF document below.

What is Charcot-Marie-Tooth disease type 1A?

The Charcot-Marie-Tooth disease (CMT) is an inherited disorder of the nervous system. The disease is chronic and progressively degenerative. The CMT is classified in 5 groups and one of them, CMT1, is by far the most common form. The symptoms include muscle weakness, tremor and sensory loss (identifiable as numbness, tingling, burning sensation). The onset of the disease is commonly in the first or the second decade. Approximately 70%-80 % of CMT1 patients have the type called CMT1A, which is caused by a genetic defect of the PMP22 gene (a unit of genetic material) that is thought to function in the building of myelin on nerve cells. Myelin consists of fat and protein and insulates some parts of nerve cells and makes the signals travel faster along the nerve cell.

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

At the time of designation, Charcot-Marie-Tooth disease type 1A affected approximately 1 in 10,000 people in the European Union (EU). This was equivalent to a total of around 50,000 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. At the time of designation, this represented a population of 502,800,000 (Eurostat 2008).

What treatments are available?

No satisfactory methods exist that were authorised at the time of application. The only treatments were rehabilitation or corrective surgery.

How is this medicine expected to work?

Ascorbic acid is expected to be helpful in CMT1A due to its mechanism of action on a messenger molecule called cyclic adenosine monophosphate (cAMP). In CTM1A there are high levels of PMP22 protein and it is expected that by reducing the levels of PMP22 protein, the symptoms of the disease will improve. Ascorbic acid is thought to reduce the levels of PMP22 protein through its actions on PMP22 gene and cAMP, thus improving the symptoms of the disease.

What is the stage of development of this medicine?

The effects of ascorbic acid were evaluated in experimental models.

At the time of submission of the application for orphan designation, clinical trials in patients with Charcot Marie Tooth 1A disease were ongoing.

The medicinal product was not authorised anywhere worldwide for treatment of Charcot-Marie-Tooth disease type 1A or designated as orphan medicinal product elsewhere for this condition, at the time of submission.

In accordance with Regulation (EC) No 141/2000 of 16 December 1999, the COMP adopted a positive opinion on 6 February 2008 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>Ascorbic acid</p>
Active substanceAscorbic acid
Medicine Name
Disease/conditionTreatment of Charcot-Marie-Tooth disease type 1A
Date of decision01/04/2008
Orphan decision numberEU/3/08/531

Review of designation

Sponsor’s contact details:

Murigenetics SAS
10 rue Clapier
13001 Marseille
Telephone: +33 68 35 76 054
Telefax: +33 491 324 387

Patients’ associations contact points:

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.