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Orphan designation

On 17 January 2018, orphan designation (EU/3/17/1969) was granted by the European Commission to the University of Cambridge, United Kingdom, for recombinant adeno-associated viral vector serotype 2/1 encoding human beta-hexosaminidase alpha and beta subunits (also known as CAM-GM201) for the treatment of GM2 gangliosidosis.

What is GM2 gangliosidosis?

GM2 gangliosidosis is an inherited disorder that causes progressive damage to the nerve cells in the brain and spinal cord.

Patients with this condition lack an enzyme called beta-hexosaminidase A, which normally breaks down substances called GM2 gangliosides. Without this enzyme, GM2 gangliosides build up in the body, particularly in the brain and spinal cord. Signs and symptoms include muscle weakness and problems with walking, intellectual disability, difficulty speaking, seizures (fits), loss of sight and hearing.

GM2 gangliosidosis is a debilitating and life-threatening disease. The most severe form of the disease starts in early infancy and can lead to death in childhood.

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

At the time of designation, GM2 gangliosidosis affected approximately 0.5 in 10,000 people in the European Union (EU). This was equivalent to a total of around 26,000 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. This represents a population of 515,700,000 (Eurostat 2017).

What treatments are available?

At the time of designation, no satisfactory methods were authorised in the EU to treat GM2 gangliosidosis. Treatment of patients was mainly supportive and included physical therapy and medicines to manage seizures.

How is this medicine expected to work?

The medicine is made of a virus that contains the gene for beta-hexosaminidase A, the enzyme that is missing in patients with GM2 gangliosidosis. After the medicine is injected into the patient’s brain, the virus is expected to carry the gene into the nerve cells, enabling them to produce the missing enzyme, which can then break down GM2 ganglioside.

The type of virus used in this medicine (‘adeno-associated virus’) does not cause disease in humans.

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 the medicine in experimental models was ongoing.

At the time of submission, no clinical trials with the medicine in patients with GM2 gangliosidosis had been started.

At the time of submission, the medicine was not authorised anywhere in the EU for GM2 gangliosidosis 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 7 December 2017 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>Recombinant adeno-associated viral vector serotype 2/1 encoding human beta-hexosaminidase alpha and beta subunits</p>
Active substanceRecombinant adeno-associated viral vector serotype 2/1 encoding human beta-hexosaminidase alpha and beta subunits
Medicine Name
Disease/conditionTreatment of GM2 gangliosidosis
Date of decision17/01/2018
Orphan decision numberEU/3/17/1969

Review of designation

Sponsor’s contact details

University of Cambridge
Department of Medicine
Addenbroke's Hospital
Hills Road
Cambridge CB2 0QQ
United Kingdom
Tel. +44 (0)1223 336844

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.