EU/3/13/1210: Orphan designation for the treatment of hypoparathyroidism

Hypoparathyroidism is a hormone disorder where the parathyroid glands in the neck produce too little parathyroid hormone, in most cases because of damage to the parathyroid glands during surgery. Parathyroid hormone helps to regulate levels of calcium and phosphate in the body; too little of it may result in too little calcium and too much phosphate in the blood, which can produce effects on bones, nerves and muscles, including paraesthesia (tingling sensations), weakening of the bones, muscle spasms, seizures (fits) and abnormal heart beats and damage to heart muscle.

Hypoparathyroidism is a debilitating disease that is long lasting and may be life threatening due to the effects of low blood-calcium.

At the time of designation, hypoparathyroidism affected less than 5 in 10,000 people in the European Union (EU). This was equivalent to a total of fewer than 256,000 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. At the time of designation, this represented a population of 512,900,000 (Eurostat 2014).

At the time of designation, hypoparathyroidism was treated in the EU with calcium and vitamin D supplements; thiazide diuretics (a class of medicines that increase the production of urine) were also used because of their ability to lower the amount of calcium that is eliminated in the urine.

The sponsor has provided sufficient information to show that recombinant human parathyroid hormone might be of significant benefit for patients with hypoparathyroidism because it replaces the hormone that is missing, thus easing the symptoms of the disease. This assumption will need to be confirmed at the time of marketing authorisation, in order to maintain the orphan status.

Recombinant human parathyroid hormone is identical to the hormone naturally produced by the body. This medicine replaces the missing hormone and is expected to restore the body's levels of calcium and phosphate.

The medicine is made by a method known as 'recombinant DNA technology': it is made by cells into which a gene (DNA) has been introduced that makes them able to produce human parathyroid hormone.

The effects of recombinant human parathyroid hormone have been evaluated in experimental models.

At the time of submission of the application for orphan designation, clinical trials with the medicinal product in patients with hypoparathyroidism had finished.
At the time of submission, this medicine was authorised in the EU for the treatment of osteoporosis.

At the time of submission, this medicine was not authorised anywhere in the EU for hypoparathyroidism. Orphan designation of recombinant human parathyroid hormone had been granted in the United States for the treatment of hypoparathyroidism.

In accordance with Regulation (EC) No 141/2000 of 16 December 1999, the COMP adopted a positive opinion on 6 November 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.