EU/3/08/573

On 7 November 2008, orphan designation (EU/3/08/573) was granted by the European Commission to Généthon, France, for adeno-associated viral vector containing the human alpha sarcoglycan gene for the treatment of alpha sarcoglycanopathy.

What is alpha sarcoglycanopathy?

Alpha sarcoglycanopathy is an inherited disease, which causes progressive muscle weakness. It usually appears in childhood. Patients with alpha sarcoglycanopathy cannot produce a protein called alpha sarcoglycan in their muscles. This protein is needed for the muscles to work properly. The disease is due to an abnormal gene that is found on chromosome 17. For a patient to develop this disease, he or she needs to have inherited one copy of the abnormal gene from each parent. This is called ‘autosomal recessive’ transmission.

Alpha sarcoglycanopathy is a chronically debilitating and life-threatening disease.

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

At the time of designation alpha sarcoglycanopathy affected approximately 0.3 in 10,000 people in the European Union (EU)*. This is equivalent to a total of around1,500 people, and is below the threshold for orphan designation, which is 5 people in 10,000. This is based on the information provided by the sponsor and 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. This represents a population of 502,282,000 (Eurostat 2008).

What treatments are available?

At the time of submission of the application for orphan designation, no satisfactory methods for the treatment of alpha sarcoglycanopathy had been authorised in the European Union. Treatment of patients with the disease mainly involves physiotherapy as supportive treatment, but also tendon-lengthening surgery and fusion of the spine to minimise painful deformity.

How is this medicine expected to work?

This medicinal product is made up of a virus that contains a copy of the human alpha sarcoglycan gene. The virus is used to carry the gene into the muscles of the patient. The gene allows the muscles to produce the alpha sarcoglycan protein, which replaces the missing protein, relieving the symptoms of the disease and halting the progressive muscles weakness. The type of virus used in this medicine (‘adeno-associated virus’) is modified so that it does not cause disease in humans.

What is the stage of development of this medicinal product?

The evaluation of the effects of adeno-associated viral vector containing the human alpha sarcoglycan gene in experimental models is ongoing.

At the time of submission of the application for orphan designation, no clinical trials in patients with alpha sarcoglycanopathy had been initiated.

Adeno-associated viral vector containing the human alpha sarcoglycan gene was not marketed anywhere worldwide for alpha sarcoglycanopathy or designated as orphan medicinal product elsewhere for this condition, at the time of submission.

According to Regulation (EC) No 141/2000 of 16 December 1999, the Committee for Orphan Medicinal Products (COMP) adopted on 10 September 2008 a positive opinion recommending the grant of the above-mentioned 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.