• Email
  • Help

Orphan designation

On 24 July 2009, orphan designation (EU/3/09/659) was granted by the European Commission to Chroma Therapeutics Ltd, United Kingdom, for tosedostat for the treatment of acute myeloid leukaemia.

The sponsorship was transferred to Voisin Consulting S.A.R.L., France, in May 2015.

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

What is acute myeloid leukaemia?

Acute myeloid leukaemia (AML) is a cancer of the white blood cells (cells that fight against infections). In patients with AML, the bone marrow (the spongy tissue inside the large bones) produces large numbers of abnormal, immature white blood cells called ‘blasts’. These abnormal cells quickly build up in large numbers in the bone marrow and are found in the blood.

AML is a life-threatening disease because these immature cells take the place of the normal white blood cells, reducing the patient’s ability to fight infections.

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

At the time of designation, AML affected less than 2 in 10,000 people in the European Union (EU). This was 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 isbased 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 504,800,000 (Eurostat 2009).

What treatments are available?

Treatment for AML is complex and depends on a number of factors including the extent of the disease, whether it has been treated before, and the patient’s age, symptoms and general state of health. At the time of designation, the main treatments for AML were chemotherapy (medicines to kill cancer cells) and bone marrow transplantation (a complex procedure where the bone marrow of the patient is destroyed and replaced with healthy bone marrow from a matched donor).

The sponsor has provided sufficient information to show that tosedostat might be of significant benefit for patients with AML because it works in a different way to existing treatments and because early studies indicate that it may be an alternative treatment for some patients, particularly elderly patients. These assumptions 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?

Tosedostat is expected to work as an ‘aminopeptidase inhibitor’. This means that it is expected to block the activity of aminopeptidase, an enzyme that is involved in the breakdown of proteins in the body. By blocking this enzyme, tosedostat is expected to decrease the level of ‘amino acids’, the building blocks of proteins, in the body’s cells. With fewer amino acids available for the production of new proteins, cells are expected to find it harder to grow and multiply. Since cancer cells are more dependent on the production of new proteins than normal cells, tosedostat is expected to slow down the growth and spread of AML.

What is the stage of development of this medicine?

The effects of tosedostat have been evaluated in experimental models.

At the time of submission of the application for orphan designation, clinical trials in patients with AML were ongoing.

At the time of submission, tosedostat was not authorised anywhere in the EU for AML. Orphan designation of tosedostat had been granted in the United States of America for AML.

In accordance with Regulation (EC) No 141/2000 of 16 December 1999, the COMP adopted a positive opinion on 4 June 2009 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 Community) 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>tosedostat</p>
Active substancetosedostat
Medicine Name
Disease/conditionTreatment of acute myeloid leukaemia
Date of decision24/07/2009
Orphan decision numberEU/3/09/659

Review of designation

Sponsor’s contact details

Voisin Consulting S.A.R.L.
3, rue des Longs Prés
92100 Boulogne Billancourt
Tel. +33 141318300
Fax +33 146205338

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.