Effect of Cinacalcet on Parathyroid Hormone Secretion in Children and Adolescents With Hypophosphatemic Rickets - Tabular View

This Tabular View shows the required WHO registration data elements as marked by ^†

Tracking Information

First Received Date ^†

September 13, 2005

Last Updated Date

October 22, 2007

Start Date ^†

June 2005

Current Primary Outcome Measures ^†

The primary outcome will be the effect of cinacalcet on serum PTH. [ Time Frame: PTH will be measured at time 0 and then every 30 minutes for 4 hours after receiving the medications ]

Original Primary Outcome Measures ^†

Same as current

Change History

Complete list of historical versions of study NCT00195936 on ClinicalTrials.gov Archive Site

Current Secondary Outcome Measures ^†

Secondary outcome will be the effect of the calcimimetic on mineral homeostasis; ionized calcium, total calcium, and phosphate will be measured. [ Time Frame: At time 0 and then every 30 minutes for 4 hours after receiving the medications ]

Original Secondary Outcome Measures ^†

Same as current

Descriptive Information

Brief Title ^†

Effect of Cinacalcet on Parathyroid Hormone Secretion in Children and Adolescents With Hypophosphatemic Rickets

Official Title ^†

Effect of Calcimimetic (Cinacalcet) on Phosphate-Induced Hyperparathyroidism in Children With Hypophosphatemic Rickets

Brief Summary

This study will measure the effect of cinacalcet (Sensipar) on parathyroid hormone (PTH) secretion in children and adolescents with hypophosphatemic rickets (XLH). The investigators are seeking evidence that patients with XLH may benefit from treatment with cinacalcet by achieving better control of PTH secretion.

Detailed Description

X-linked hypophosphatemic rickets (XLH) is an X-linked dominant genetic disorder. Common findings are low serum phosphate and inadequate 1,25(OH)2 vitamin D production. It is generally believed that the primary defect in XLH is impaired renal tubular transport of phosphate coupled with abnormal regulation of the enzyme responsible for the 1-alfa hydroxylation of 25(OH) vitamin D. The current treatment of children with XLH is large oral doses of phosphate and 1,25-dihydroxyvitamin D. There are two common side effects to this treatment; nephrocalcinosis and secondary hyperparathyroidism (HPT).

The latter at times may cause hypertension, hypercalcemia, and permanent renal damage. The complication of secondary hyperparathyroidism is seen in 20% of the patients. The release of PTH from the glands into the circulation is tightly regulated by serum calcium concentration. The glands "read" serum calcium concentration via Ca sensing receptors (CaR) which are located at the surface of the glands. Calcimimetics are compounds that allosterically modulate the CaR, thereby enhancing its sensitivity to circulating serum calcium concentrations and consequently decreasing PTH secretion. When used in primary HPT, they rapidly reduce PTH level and normalize serum calcium concentration.

Cinacalcet is a calcimimetic agent recently approved by the FDA for treating hypercalcemia in patients with parathyroid carcinoma and secondary HPT in patients with chronic renal disease. Cinacalcet was found to be effective in decreasing both PTH level and the calcium X phosphorous ion product in dialysis patients.

The goal of our proposed acute study is to see whether concomitant administration of Cinacalcet and phosphate, to patients with XLH, will block completely or partially secretion of PTH (day 2), expected to be seen following administration of phosphate alone (day 1). We will also monitor serum phosphate, total calcium, and ionized calcium concentration to learn to what extent, if any, blockage of PTH secretion affects mineral homeostasis under this condition.

If found to be effective in blocking PTH secretion, Cinacalcet will become a candidate for a long-term study in children with XLH to protect them from developing secondary hyperparathyroidism.

Study Phase

Phase I

Study Type ^†

Interventional

Study Design ^†

Treatment, Non-Randomized, Open Label, Uncontrolled, Single Group Assignment, Safety/Efficacy Study

Condition ^†

Hypophosphatemic Rickets, X-Linked Dominant

Intervention ^†

Drug: Cinacalcet

Study Arms / Comparison Groups

Publications *

* Includes publications given by the data provider as well as publications identified by National Clinical Trials Identifier (NCT ID) in Medline.

Recruitment Information

Recruitment Status ^†

Recruiting

Enrollment ^†

Completion Date

Primary Completion Date

Eligibility Criteria ^†

Inclusion Criteria:

Established patients with XLH
Age 5 years old and above
Normal serum calcium and creatinine concentrations

Exclusion Criteria:

Patients with hypersensitivity to any component(s) of cinacalcet
Hypocalcaemia
Elevated serum creatinine

Gender

Both

Ages

5 Years and older

Accepts Healthy Volunteers

Contacts ^††

Contact: Rachel Levy-Olomucki, MD

816-234-3010

rlevy@cmh.edu

Location Countries ^†

United States

Expanded Access Status

Administrative Information

NCT ID ^†

NCT00195936

Responsible Party

Secondary IDs ^††

Study Sponsor ^†

Children's Mercy Hospital Kansas City

Collaborators ^††

Investigators ^†

Principal Investigator:

Rachel Levy-Olomucki, MD

Section of Pediatric Nephrology, Children's Mercy Hospitals and Clinics

Information Provided By

Children's Mercy Hospital Kansas City

Verification Date

August 2005

^† Required WHO trial registration data element.
^†† WHO trial registration data element that is required only if it exists.