EU/3/19/2227: Orphan designation for the treatment of tenosynovial giant cell tumour, localised and diffuse type

Tenosynovial giant cell tumour is a condition where the tissue surrounding the joints and tendons, called the synovial lining or synovium, expands abnormally forming outgrowths of the joint. It is known as 'localised' if only one site of the joint is affected, or 'diffuse' when several sites are affected. It usually affects a single joint in the hand, knee or hip of young and middle-aged adults and is characterised by pain, swelling and stiffness of the joint.

Tenosynovial giant cell tumour is a long-term debilitating disease because it leads to loss of joint function and joint damage.

At the time of designation, tenosynovial giant cell tumour affected approximately 3 in 10,000 people in the European Union (EU). This was equivalent to a total of around 93,000 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 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).

At the time of designation, no satisfactory methods were authorised in the EU for the treatment of tenosynovial giant cell tumour and treatment consisted of surgery and medicines to reduce inflammation.

Tenosynovial giant cell tumours release an excessive amount of a protein called CSF1. This protein attracts more cells and makes them multiply, so making the tumour grow larger. The medicine stops the receptors (targets) for CSF1 on the cells working properly. By reducing the effect of CSF1, the medicine is expected to reduce growth of the tumour and so reduce symptoms of the disease. 

The effects of the medicine have been evaluated in experimental models.

At the time of submission of the application for orphan designation, clinical trials with the medicine in patients with tenosynovial giant cell tumour were ongoing.

At the time of submission, the medicine was not authorised anywhere in the EU for the treatment of tenosynovial giant cell tumour, localised and diffuse type, 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 7 November 2019, recommending the granting of this designation.

• 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.