EU/3/01/051: Orphan designation for the treatment of systemic secondary amyloidosis

Amyloid is the name of a group of proteins that can be found in the body. These proteins are attached to sugar units, and are similar to starch (a protein found in plants). Normally, these proteins easily melt in water and liquids of the body, like in the blood. In some cases, however, the amyloid proteins lose their shape, become solid and deposit in certain parts of the body, which is unable to degrade them. These deposits can be harmful to organs in the body and this condition is called amyloidosis. To make the diagnosis a biopsy is required (a small piece of tissue is taken from the body and studied with a microscope).

The symptoms of amyloidosis depend on the organs affected and on the extent of the deposit. In systemic amyloidosis deposits are found throughout the body. Systemic amyloidosis can be classified into three major types: primary systemic amyloidosis, secondary systemic amyloidosis and hereditary systemic amyloidosis. Secondary systemic amyloidosis occurs in patients who have a chronic infection or inflammatory disease such as tuberculosis, a genetic disease called familial Mediterranean fever, bone infections (osteomyelitis), rheumatoid arthritis, inflammation of the small intestine (granulomatous ileitis), Hodgkin's disease or leprosy. The amyloid tissue deposits in secondary amyloidosis consist of AA amyloid proteins. Systemic secondary amyloidosis is a life-threatening condition.

At the time of designation, systemic secondary amyloidosis affected approximately 1.7 in 10,000 people in the European Union (EU). This was equivalent to a total of around 64,000 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 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. At the time of designation, this represented a population of 378,800,000 (Eurostat 2001).

At the time of submission of application for orphan-drug designation there was no treatment of systemic secondary amyloidosis in the European Union except colchicine, which was authorised for treatment of familial Mediterranean fever.
Satisfactory argumentation has been submitted by the sponsor to justify the assumption that 1,3-propanedisulfonic acid, disodium salt might be of potential significant benefit for the treatment of systemic secondary amyloidosis. The assumption will have to be confirmed at the time of marketing authorisation. This will be necessary to maintain the orphan status.

The AA amyloid proteins that cause systemic secondary amyloidosis are protected from degradation because they are hidden within hard structures called fibrillar aggregate deposits. These contain different substances such as sulfated glycosaminoglycans. 1,3-Propanedisulfonic acid is expected to compete with sulfated glycosaminoglycans, and thus prevent formation of aggregates improving the symptoms of the disease.

The effects of 1,3-propanedisulfonic acid, disodium salt were evaluated in experimental models.

At the time of submission of the application for orphan designation, clinical trials in patients with systemic secondary amyloidosis were ongoing.

1,3-Propanedisulfonic acid, disodium salt was not marketed anywhere worldwide for treatment of systemic secondary amyloidosis, at the time of submission. Orphan designation of 1,3-propanedisulfonic acid, disodium salt was granted in April 1999 in the United States for the treatment of secondary (AA) amyloidosis.

In accordance with Regulation (EC) No 141/2000 of 16 December 1999, the COMP adopted a positive opinion on 12 June 2001 recommending the granting of this designation.

• the seriousness of the condition,
• the existence of alternative methods of diagnosis, prevention or treatment and
• 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.