EU/3/06/359

On 6 April 2006 orphan designation (EU/3/06/359) was granted by the European Commission to Généthon, France, for adeno-associated viral vector containing the human calpain 3 gene for the treatment of calpainopathy.

What is calpainopathy?

Calpainopathy is a genetic disease that is inherited as an autosomal recessive characteristic; the genetic abnormality is independent of patient’s sex and it is only expressed when both parents pass it on to their children. The condition belongs to the larger group of the limb girdle muscular dystrophies (LGMD). Patients suffering from this disorder do not produce the calpain 3 protein in the muscle cells. It is characterised by progressive diminishing and weakness of the muscles. Calpainopathy is a chronically debilitating and life-threatening condition.

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

At the time of designation, calpainopathy affected approximately 0.1 in 10,000 people in the European Union (EU)*. This is equivalent to a total of around 4,600 people, 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).

* Disclaimer: For the purpose of the designation, the number of patients affected by the condition is estimated and assessed based on data from the European Union (EU 25), Norway, Iceland and Liechtenstein. This represents a population of 459,700,000 (Eurostat 2004).

What treatments are available?

At the time of submission of the application for orphan designation, no satisfactory method had been authorised in the European Union for treatment of the condition. Treatment of patients with calpainopathy primarily involved physiotherapy and supportive treatments, but also surgery of tendons and, in some cases, spine fusion.

How is this medicine expected to work?

Adeno-associated viral vector containing the human calpain 3 gene is a medicinal product that uses a type of virus (known as adenovirus) to carry the gene necessary for the production of the protein calpain 3. Virus is used because it is capable of introducing genetic material, in this case a healthy copy of the gene that is defective in these patients, in cells. The type of virus (adeno-associated virus) used in this medicinal product is modified not to cause any disease in humans. By introducing a healthy copy of the affected gene, this product is expected to produce the calpain 3 protein, and thus improve the symptoms of the patients.

What is the stage of development of this medicine?

The evaluation of the effects of adeno-associated viral vector containing the human calpain 3 gene in experimental models was ongoing.

At the time of submission of the application for orphan designation, no clinical trials in patients with containing the human calpain 3 gene were initiated.

Adeno-associated viral vector containing the human calpain 3 gene was not marketed anywhere worldwide for calpainopathy 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 8 March 2006 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;
• and either the rarity of the condition (affecting not more than five in 10,000 people in the Community) or the 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 the quality, safety and efficacy is necessary before a product can be granted a marketing authorisation.