EU/3/13/1151: Orphan designation for the treatment of malignant thymoma

Malignant thymoma is a cancer of the thymus, a gland below the breastbone that is involved in producing infection-fighting cells. Malignant thymoma is most often seen in middle-aged or older people. There may be no symptoms, but some patients have cough, chest pain and difficulty breathing. Up to about half of all patients with malignant thymoma also have myasthenia gravis, a disease causing muscle weakness.

Malignant thymoma is a long-term debilitating and potentially life-threatening illness that is associated with poor long-term survival.

At the time of designation, malignant thymoma affected approximately 0.25 in 10,000 people in the European Union (EU). This was equivalent to a total of around 12,000 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 27), Norway, Iceland and Liechtenstein. This represents a population of 509,000,000 (Eurostat 2013).

At the time of designation, no satisfactory treatment was authorised in the EU for patients affected by the condition. Treatments for malignant thymoma included surgery, radiotherapy (treatment with radiation), and chemotherapy (medicines to treat cancer).

Belinostat is an 'HDAC inhibitor' medicine. This means that it blocks enzymes called histone deacetylases (HDACs), which are involved in turning genes 'on' and 'off' within cells. By blocking HDAC enzymes, belinostat is expected to 'switch on' the genes that suppress the division and growth of the tumour cells in malignant thymoma. This is expected to lead to a reduction in the growth and spread of the cancer cells.

The effects of belinostat have been evaluated in experimental models.

At the time of submission of the application for orphan designation, a clinical trial with belinostat in patients with malignant thymoma was ongoing.

At the time of submission, belinostat was not authorised anywhere in the EU for malignant thymoma 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 13 June 2013 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.