HEXT (Hypo Studies EXTended)
Hypoparathyroidism is a rare disorder in which parathyroid hormone (PTH) is markedly decreased or absent from the circulation. It is the only remaining hormone deficiency state for which replacement with the missing hormone has been heretofore unavailable. The hypoparathyroid state is due either to autoimmune destruction of the parathyroid glands or to loss of parathyroid function after neck surgery. Without PTH, calcium homeostasis is markedly abnormal, the most salient clinical feature of which is a reduced serum calcium concentration. The hypocalcemia is associated with other important abnormalities such as markedly reduced parameters of bone turnover. PTH (1-84) is the ideal therapeutic approach to hypoparathyroidism. The current mainstay of therapy, calcium and vitamin D, has important clinical limitations. Large doses of calcium and vitamin D are required and often associated with hypercalciuria and vitamin D toxicity. Moreover, this approach does not correct the skeletal deficiencies resident in the bones themselves due to lack of PTH. In contrast, PTH (1-84) replaces precisely what is missing in this disorder. Our research question is: What are the long-term safety and efficacy parameters of PTH(1-84) therapy in hypoparathyroidism?
Preliminary data suggest that treatment with PTH(1-84) for up to 2 years improves control of the serum and urine calcium concentration safely.
Since hypoparathyroidism is a chronic disorder, it is important to know whether these salutary effects continue to be seen beyond 2 years. There is a need to determine the safety and efficacy treatment of PTH(1-84) in hypoparathyroidism beyond 2 years.
|Study Design:||Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||HEXT: The Hypoparathyroidism Studies, Extended: the Effect of PTH on the Skeleton in Hypoparathyroidism|
- control of serum and urinary calcium [ Time Frame: every 6 months, up to 4 years ] [ Designated as safety issue: No ]To determine the actions of PTH(1-84) to provide long-term control of serum calcium and urinary calcium excretion with use of standard amounts of calcium and vitamin D supplementation.
- quality of life [ Time Frame: every 6 months, up to 4 years ] [ Designated as safety issue: No ]To determine the extent to which PTH(1-84) improves quality of life on a long-term basis
- safety of PTH(1-84) [ Time Frame: every 6 months, up to 4 years ] [ Designated as safety issue: Yes ]To establish the safety of PTH(1-84) when administered for up to 10 years
|Study Start Date:||December 2009|
|Estimated Study Completion Date:||March 2015|
|Estimated Primary Completion Date:||December 2014 (Final data collection date for primary outcome measure)|
Experimental: open-label PTH(1-84)
open-label PTH(1-84) / variable dosing: 25mcg every other day, 25mcg every day, 50mcg every day, 75mcg every day, 100mcg every day
Drug: open-label PTH(1-84)
open label PTH(1-84) at either 25mcg every other day, 25mcg every day, 50mcg daily, 75mcg daily, or 100mcg daily
|United States, New York|
|Columbia University Medical Center|
|New York, New York, United States, 10032|
|Principal Investigator:||John P Bilezikian, MD||Columbia University|