EU/3/05/316

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Orphan designation

On 26 August 2005, orphan designation (EU/3/05/316) was granted by the European Commission to Nippon Shinyaku Co. Ltd, Germany, for 2-{4-[(5,6-diphenylpyrazin-2-yl)(isopropyl)amino]butoxy}-N-(methylsulfonyl)acetamide for the treatment of pulmonary arterial hypertension and chronic thromoembolic pulmonary hypertension.

The sponsorship was transferred to Actelion Registration Limited, United Kingdom, in February 2009.

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

What is pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension?

Pulmonary arterial hypertension is a rare blood vessel disorder of the lung in which the pressure in the pulmonary artery (the vessel that leads blood from the heart to the lungs) rises above normal levels. An increase of the number of smooth muscle cells in the walls of small arteries (a phenomenon called proliferation) that are remodelling the vessels, may lead to obstructions in the microcirculation, which will then lead to an increase in the blood pressure.

Chronic thromboembolic pulmonary hypertension is a complication representing less than 1% of all cases of acute pulmonary embolism (the sudden blocking of a lung artery by a clot or foreign material which has been brought to its site by the blood current), which directly leads to pulmonary hypertension. Pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension are chronically debilitating and life-threatening.

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

At the time of designation, pulmonary arterial hypertension and chronic thromoembolic pulmonary hypertension affected between 1 and 3 in 10,000 people in the European Union (EU). This was equivalent to a total of between 47,000 and 140,000 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 25), Norway, Iceland and Liechtenstein. At the time of designation, this represented a population of 466,600,000 (Eurostat 2005).

What treatments are available?

Several medicinal products were authorised for the treatment of pulmonary arterial hypertension in the Community at the time of submission of the application for orphan drug designation.

2-{4-[(5,6-diphenylpyrazin-2-yl)(isopropyl)amino]butoxy}-N-(methylsulfonyl)acetamide might be of potential significant benefit for the treatment of pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension because it might improve the long-term outcome of the patients. 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?

In pulmonary arterial hypertension there appears to be an imbalance between vasoconstrictors (substances produced by certain cells that help to narrow the blood vessels) and vasodilators (substances produced by other cells that help to widen the blood vessels, such as prostacyclin). This imbalance seems to be caused, at least in part, by the lack or reduction of a certain enzyme, prostacyclin synthase, responsible to convert prostacyclin into his active form. Prostacyclin causes vasodilatation and has also a strong effect in blocking the platelets (blood cells responsible to make the blood clot) to make the clot. 2-{4-[(5,6-diphenylpyrazin-2-yl)(isopropyl)amino]butoxy}-N-(methylsulfonyl)acetamide is a substance similar to prostacyclin and is expected to act in a similar way on the pulmonary arteries in patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension.

What is the stage of development of this medicine?

The effects of 2-{4-[(5,6-diphenylpyrazin-2-yl)(isopropyl)amino]butoxy}-N-(methylsulfonyl) acetamide were evaluated in experimental models.

At the time of submission of the application for orphan designation, no clinical trials in patients with pulmonary arterial hypertension and chronic thromoembolic pulmonary hypertension were initiated.

2-{4-[(5,6-diphenylpyrazin-2-yl)(isopropyl)amino]butoxy}-N-(methylsulfonyl)acetamide was not authorised anywhere worldwide for pulmonary arterial hypertension and chronic thromoembolic pulmonary hypertension 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 13 July 2005 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>2-{4-[(5,6-Diphenylpyrazin-2-yl)(isopropyl)amino]butoxy}-N-(methylsulfonyl)acetamide</p>
Active substance2-{4-[(5,6-Diphenylpyrazin-2-yl)(isopropyl)amino]butoxy}-N-(methylsulfonyl)acetamide
Medicine Name
Disease/conditionTreatment of pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension
Date of decision26/08/2005
OutcomePositive
Orphan decision numberEU/3/05/316

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

Actelion Registration Limited
Chiswick Tower 13th floor
389 Chiswick High Road
London W4 4AL
United Kingdom
Tel. + 44 (0)20 8987 3320
Fax + 44 (0)20 8987 3322
E-mail: registration@actelion.com

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.