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Orphan designation

On 21 March 2012, orphan designation (EU/3/12/975) was granted by the European Commission to Ferring Pharmaceuticals A/S, Denmark, for carbetocin for the treatment of Prader-Willi syndrome.

The sponsorship was transferred to Voisin Consulting S.A.R.L., France, in March 2018.

What is Prader-Willi syndrome?

Prader-Willi syndrome is a genetic condition caused by damage to specific areas of chromosome 15. This causes a wide range of symptoms, some of which can appear at birth, such as feeding problems, small size and reduced muscle strength. During childhood further symptoms develop, including a constant desire to eat food often leading to severe obesity, short stature, incomplete sexual development, learning difficulties and behavioural problems, such as aggression and stubbornness.

Prader-Willi syndrome is a life-long debilitating and life-threatening disease because of its serious symptoms, particularly learning difficulties, behavioural problems and obesity.

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

At the time of designation, Prader-Willi syndrome affected less than 2 in 10,000 people in the European Union (EU)*. This is equivalent to a total of fewer than 101,000 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 506,300,000 (Eurostat 2011).

What treatments are available?

At the time of designation, growth hormone was authorised in the EU for treating Prader-Willi syndrome. In addition, patients’ symptoms were treated or managed in various ways, including supervised access to food to prevent obesity.

The sponsor has provided sufficient information to show that carbetocin might be of significant benefit for patients with Prader-Willi syndrome because it works in a different way to the existing treatment and early studies in experimental models show that it may improve the behavioural symptoms of this condition. This assumption will need to be confirmed at the time of marketing authorisation, in order to maintain the orphan status.

How is this medicine expected to work?

Carbetocin is similar to oxytocin, a hormone mostly associated with childbirth because of its effect in uterine (womb) contractions but which is also thought to influence several aspects of behaviour. A lack of oxytocin is thought to contribute to the behavioural problems seen in Prader-Willi syndrome. Carbetocin is expected to activate to the oxytocin receptors, and thereby mimic oxytocin’s function in patients with Prader-Willi syndrome. This is expected to reduce their behavioural problems.

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 carbetocin in experimental models was ongoing.

At the time of submission, no clinical trials with carbetocin in patients with Prader-Willi syndrome had been started.

At the time of submission, carbetocin was not authorised anywhere in the EU for Prader-Willi 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 11 January 2012 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>Carbetocin</p>
Active substanceCarbetocin
Medicine Name
Disease/conditionTreatment of Prader-Willi syndrome
Date of decision21/03/2012
Orphan decision numberEU/3/12/975

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

Voisin Consulting S.A.R.L.
64 Avenue Pierre Grenier
92100 Boulogne-Billancourt
Tel. +33 1413 18300

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.