EU/3/19/2193 - orphan designation for treatment of periodic paralysis

acetazolamide

Overview

On 21 August 2019, orphan designation EU/3/19/2193 was granted by the European Commission to Laboratorios Tillomed Spain, S.L.U, Spain, for acetazolamide for the treatment of periodic paralysis.

What is periodic paralysis?

Periodic paralysis is a group of inherited muscle disorders that causes periodic attacks of weakness or paralysis (inability to move), which resolve spontaneously after some time. The attacks can be triggered by stress, excitement, physical activity, heat or cold. Muscle weakness can affect a small group of muscles or can be more generalised and affect the whole body.

Periodic paralysis is caused by abnormalities in the ion channels, tiny pores in the muscle cells that control the passage of charged particles (ions) such as sodium or chloride and play a key role in the contraction and relaxation of muscles.

Periodic paralysis is a long-term debilitating disorder due to permanent muscle weakness, muscle pain and the need for mobility aids. It can be life threatening because of the risk of heart arrhythmias (unstable heartbeat) which could lead to a heart attack.

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

At the time of designation, periodic paralysis affected approximately 0.2 in 10,000 people in the European Union (EU). This was equivalent to a total of around 10,000 people¹, 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).

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¹Disclaimer: 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. This represents a population of 518,400,000 (Eurostat 2019).

What treatments are available?

At the time of submission, no satisfactory methods were authorised in the EU for the treatment of periodic paralysis. Patients received advice on diet and lifestyle to reduce the risk of triggering attacks.

How is this medicine expected to work?

Acetazolamide has been available in the EU for many years for various uses including the treatment of certain types of epilepsy, fluid build-up in the tissues (oedema) and glaucoma (high pressure inside the eye). How it works in periodic paralysis is not fully understood, but it is thought to increase the removal of potassium through the urine and also to increase the acidity of the body, which can change the way the ion channels work in muscle cells.

What is the stage of development of this medicine?

The effects of acetazolamide have been evaluated in experimental models.

At the time of submission of the application for orphan designation, no clinical trials with acetazolamide in patients with periodic paralysis had been started.

At the time of submission, acetazolamide was authorised in EU countries for glaucoma, epilepsy and as a diuretic (a medicine to increase urination) in patients with abnormal retention of fluids. It was not authorised anywhere in the EU for the treatment of periodic paralysis or designated as an orphan medicinal product elsewhere for this condition.

In accordance with Regulation (EC) No 141/2000, the COMP adopted a positive opinion on 18 July 2019, 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.

EU/3/19/2193: Public summary of positive opinion for orphan designation of acetazolamide for the treatment of periodic paralysis

Reference Number: EMADOC-628903358-1303

Key facts

• Active substance:
  acetazolamide
• Intended use:
  Treatment of periodic paralysis
• Orphan designation status:
  Positive
• EU designation number:
  EU/3/19/2193
• Date of designation:
  21/08/2019
• Sponsor:

  Laboratorios Tillomed Spain, S.L.U; Calle Del Cardenal Marcelo Spinola 8 1º F; 28016 Madrid; Spain; Tel: [phone]; E-mail: [e-mail]

Review of designation

The Committee for Orphan Medicinal Products reviews the orphan designation of a product if it is approved for marketing authorisation.