Shire plc has announced that the European Commission (EC) has granted Conditional Marketing Authorisation for Natpar (rhPTH[1-84]), the first recombinant human protein with the full length 84-amino acid sequence of endogenous parathyroid hormone (PTH). Natpar will be the first and only approved hormone therapy indicated as adjunctive treatment for adult patients with chronic hypoparathyroidism who cannot be adequately controlled with standard therapy alone. Hypoparathyroidism is a rare endocrine disease resulting from an inappropriately low circulating PTH concentration.

‘‘As the first and only licensed recombinant parathyroid hormone treatment in Europe for chronic hypoparathyroidism, Natpar represents a historical and timely innovation for patients who cannot be adequately controlled on calcium and vitamin D alone,” said Philip J. Vickers, Ph.D., global head of research and development at Shire. “The approval of Natpar offers an important advance in the management of this rare endocrine disorder for patients in Europe.”

The Conditional Marketing Authorisation is based on the outcomes from the Phase III efficacy and safety of rhPTH(1-84) clinical trial (REPLACE) in patients aged 19-74 years with chronic hypoparathyroidism. The trial showed that Natpar maintained serum calcium while reducing oral calcium and active vitamin D supplemental doses.

“Chronic hypoparathyroidism can carry a significant disease burden, and some patients are not well-controlled, showing fluctuations in their serum calcium levels,” said professor Maria Louisa Brandi, Department of Internal Medicine, University of Florence, Italy. “Clinical studies have shown Natpar maintains serum calcium while reducing the need for calcium and vitamin D for patients with chronic hypoparathyroidism.”

With this approval, Shire is now authorized to market Natpar in the 28 Member States of the European Union (EU), as well as in Iceland, Liechtenstein and Norway. Natpar falls under the scope of European Commission Regulation as eligible for Conditional Marketing Authorisation because it is designated as an orphan medicinal product and fulfills an unmet medical need.

Hypoparathyroidism is a rare disease that occurs when inadequate levels of PTH are secreted by the parathyroid glands, resulting in a mineral imbalance in the body expressed by a low concentration of calcium (hypocalcemia) and a high concentration of phosphate (hyperphosphatemia) in the blood.

Guidelines from the European Society of Endocrinology (ESE) state that a diagnosis of chronic hypoparathyroidism should be considered in a patient with hypocalcemia and an inappropriately low PTH concentration. Guidelines recommend that treatment should aim to restore mineral homeostasis and prevent symptoms of hypocalcemia while optimizing overall well-being. Typical symptoms of hypocalcemia include muscle spasms and cramping.

To date, management of chronic hypoparathyroidism has focused on maintaining serum calcium with oral calcium and active vitamin D supplements; however, some patients are not adequately controlled and still have variations in their serum calcium levels.