On 22 August 2014, orphan designation (EU/3/14/1331) was granted by the European Commission to IDEA Innovative Drug European Associates Limited, the United Kingdom, for recombinant fusion protein consisting of a modified form of the extracellular domain of human activin receptor IIB linked to the human IgG1 Fc domain for the treatment of myelodysplastic syndromes.

This medicine is now known as luspatercept.

The sponsorship was transferred to Celgene Europe Limited, United Kingdom, in June 2015 and subsequently to Celgene Europe B.V., The Netherlands, in September 2018.

Recombinant fusion protein consisting of a modified form of the extracellular domain of human activin receptor IIB linked to the human IgG1 Fc domain for treatment of myelodysplastic syndromes has been authorised in the EU as Reblozyl since 25 June 2020. 

The sponsorship was transferred to Bristol-Myers Squibb Pharma EEIG, Ireland in February 2021.

Myelodysplastic syndromes are a group of disorders in which the red blood cells, white blood cells and platelets produced by the bone marrow (the spongy tissue inside the large bones) do not grow and mature normally. Patients with myelodysplastic syndromes can develop several symptoms including tiredness or weakness due to anaemia (low red blood cell counts), infections due to low white blood cells, and bruising or abnormal bleeding due to low platelet counts.

Myelodysplastic syndromes are long-term debilitating and life-threatening diseases because they can lead to severe anaemia, infections or bleeding, and can result in leukaemia (cancer of the white blood cells).

At the time of designation, myelodysplastic syndromes affected approximately 2 in 10,000 people in the European Union (EU). This was equivalent to a total of around 103,000 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 28), Norway, Iceland and Liechtenstein. At the time of designation, this represented a population of 512,900,000 (Eurostat 2014).

At the time of designation, some medicines were authorised in the EU for the treatment of MDSs. The choice of treatment for MDSs depended on a number of factors, including the type and the extent of the disease, whether it had been treated before, and the patient's age, symptoms and general state of health. The main treatments for MDSs included chemotherapy (medicines to treat cancer) and bone marrow transplantation. This is a complex procedure where the bone marrow of the patient is cleared of cells and replaced with healthy bone marrow cells from a matched donor.

The sponsor has provided sufficient information to show that this medicine might be of significant benefit for patients with myelodysplastic syndromes because it works in a different way to existing treatments and early studies show that it may improve anaemia, an important aspect of these conditions. This assumption will need to be confirmed at the time of marketing authorisation, in order to maintain the orphan status.

This medicine is an engineered protein that has been designed to attach to certain proteins in the body which slow down (or inhibit) the development of red blood cells. By attaching to these 'inhibitory' proteins, it is expected to trap them so they don't have their normal effect on the red blood cells. As a result, production of red blood cells is increased. This is expected to improve the anaemia of patients with myelodysplastic syndromes.

The effects of this medicine have been evaluated in experimental models.

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

At the time of submission, the medicine was not authorised anywhere in the EU for myelodysplastic syndromes. Orphan designation of the medicine had been granted in the United States for these conditions.

In accordance with Regulation (EC) No 141/2000 of 16 December 1999, the COMP adopted a positive opinion on 10 July 2014 recommending the granting of this designation.

  • 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

Active substance
Recombinant fusion protein consisting of a modified form of the extracellular domain of human activin receptor IIB linked to the human IgG1 Fc domain (luspatercept)
Intended use
Treatment of myelodysplastic syndromes
Orphan designation status
EU designation number
Date of designation

Bristol-Myers Squibb Pharma EEIG
Plaza 254
Blanchardstown Corporate Park 2
Dublin 15
D15 T867
Tel. +353 1 483 3857
E-mail: medical.information@bms.com

Review of designation

The Committee for Orphan Medicinal Products reviewed the orphan designation of Reblozyl at the time of marketing authorisation, and confirmed that the orphan designation should be maintained. 

More information is available in the Reblozyl : Orphan maintenance assessment report (initial authorisation).

EMA list of opinions on orphan medicinal product designation

EMA publishes information on orphan medicinal product designation adopted by the Committee for Orphan Medicinal Products (COMP) on the IRIS online platform:

Patients' organisations

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

  • European Organisation for Rare Diseases (EURORDIS), a non-governmental alliance of patient organisations and individuals active in the field of rare diseases.

  • Orphanet, a database containing information on rare diseases, which includes a directory of patients’ organisations registered in Europe.

EU register of orphan medicines

The list of medicines that have received an orphan designation in the EU is available on the European Commission's website:

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