Drug safety evaluation of parathyroid hormone for hypocalcemia in patients with hypoparathyroidism.

Hypoparathyroidism is a rare disorder characterized by low serum calcium levels and high serum phosphate levels, and low or inappropriately normal levels of parathyroid hormone (PTH). This disease is commonly treated with calcium supplements and active vitamin D metabolites or analogues, but large doses of these supplements are often utilized to relieve the symptoms caused by hypocalcemia, without guarantee of a physiological normalization of calcium-phosphate homeostasis. Areas covered: Several studies have investigated replacement therapy with recombinant human PTH [rhPTH (1-84) and rhPTH (1-34)] for subjects with hypoparathyroidism. In 2015, The Food and Drug Administration (FDA) approved, in the United States, rhPTH (1-84), named Natpara®, a bioenginerred rhPTH, for the management of chronic hypoparathyroidism not well controlled with conventional therapy. This article evaluates the safety and tolerability of rhPTH (1-84) in patients with chronic hypoparathyroidism, and also describes the studies conducted so far on rhPTH (1-34) used for chronic hypoparathyroidism. Expert opinion: The research done in this field has shown that replacement treatment with rhPTH is an attractive option for subjects with hypoparathyroidism who are unable to maintain stable and safe serum and urinary calcium levels. However, since therapy with rhPTH is a long-term management option in hypoparathyroidism, more long-term safety data are needed.