EU/3/18/2299: Orphan designation for the treatment of achondroplasia

Achondroplasia represents the most common form of short-limb dwarfism, a condition where the bones in the arms and legs do not form properly and are shorter than normal. Patients with achondroplasia have a short stature, an enlarged head with a prominent forehead, bowed legs, ear problems, compression of the spinal cord, as well as short fingers, toes, lower legs and upper arms.

Achondroplasia is an inherited disease caused by a mutation (change) in a gene responsible for making a protein called fibroblast growth-factor receptor 3 (FGFR3). Patients who have inherited the defective gene from both parents are the most severely affected and normally die around birth or a few months afterwards. In patients with only one defective FGFR3 gene, achondroplasia causes long-term disability and may result in a shorter life span.

At the time of designation, achondroplasia affected approximately 0.6 in 10,000 people in the European Union (EU). This was equivalent to a total of around 30,000 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).

*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, Iceland, Liechtenstein, Norway and the United Kingdom. This represents a population of 519,200,000 (Eurostat 2020).

At the time of designation, no satisfactory methods were authorised in the EU for the treatment of achondroplasia. Patients were given supportive care, as well as surgery to extend limb length, to correct spinal compression or to correct bowed legs.

The exact way the medicine works is not clear. However early studies indicate that it may inhibit the action of the defective FGFR3 gene, thereby relieving symptoms of the disease.

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

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

At the time of submission, the medicine was not authorised anywhere in the EU for the treatment of achondroplasia. Orphan designation had been granted in the United States for the condition.

In accordance with Regulation (EC) No 141/2000, the COMP adopted a positive opinion on 18 June 2020, 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.