Effects of PTH Replacement on Bone in Hypoparathyroidism

Summary

Hypoparathyroidism is a rare condition associated with a low level of parathyroid hormone (PTH) in the blood. Hypoparathyroidism can be genetic and show up in childhood, or it can occur later in life. If it occurs later, it is usually due to damage or removal of the parathyroid glands during neck surgery. PTH helps control the amount of calcium in blood, kidneys, and bones. Low levels of calcium in the blood can cause a person to feel sick. It can cause cramping or tingling in the hands, feet, or other parts of the body. A very low blood calcium can cause fainting or seizures.

The standard treatment for hypoparathyroidism is a form of vitamin D (calcitriol) and calcium supplements. Keeping normal blood levels of calcium can be difficult. Sometimes there is too much calcium in the urine even if the calcium levels in the blood are low. High calcium in the kidneys and urine can cause problems such as calcium deposits in the kidney (nephrocalcinosis) or kidney stones. High levels of calcium in the kidney may keep the kidney from functioning normally. Treatment with PTH will replace the hormone you are missing. Your disease may be better controlled on PTH than on calcium and calcitriol.

Researchers at the NIH have conducted prior studies to establish synthetic human parathyroid hormone 1-34 (HPTH) as a treatment for hypoparathyroidism. Other studies have shown that PTH may improve calcium levels in blood and urine. The primary purpose of this research study is to evaluate the effects of synthetic human parathyroid hormone 1-34 (HPTH) replacement therapy on bone in adults and teenagers with hypoparathyroidism.

The study takes 5 (Omega) years to complete and requires 12 inpatient visits to the National Institutes of Health Clinical Center in Bethesda, MD. The first visit will help the study team decide whether you are eligible. This visit will last 2 to 3 days. After taking calcium and calcitriol for 1 - 7 months you will return to the NIH Clinical Center for the baseline visit. The baseline visit is the visit that you will start your PTH; you will also undergo a bone biopsy during the visit. The baseline visit may last 7 to 10 days. You will then take PTH twice a day for 5 years. You will be asked to return to the NIH clinical center every 6 months for 10 follow-up visits. During one of the follow-up visits, you will have a second bone biopsy taken from the other hip. That second biopsy will be done after 1 year, 2 years, or 4 years of taking PTH; the researchers will assign the timing of the second biopsy randomly. You will be asked to go to your local laboratory for blood and urine tests between each follow up visit. At first the blood tests will occur at least once a week. Later, you will need to go to your local laboratory for blood tests at least once a month and urine tests once every 3 months. The local laboratory visits and follow-up visits at the NIH Clinical Center will help the study team determine whether the HPTH treatment is controlling your hypoparathyroidism.

Conditions

• Hypoparathyroidism
• DiGeorge Syndrome

Interventions

DRUG

PTH 1-34

Given twice daily by subcutaneous

Sponsors & Collaborators

• National Institute of Dental and Craniofacial Research (NIDCR)

  lead NIH

Principal Investigators

• Rachel I Gafni, M.D. · National Institute of Dental and Craniofacial Research (NIDCR)

Study Design

Allocation

NA

Purpose

TREATMENT

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

70 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2006-10-30

Primary Completion

2017-09-30

Completion

2017-10-04

FDA Drug

Yes

Countries

• United States

Study Locations