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

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified August 2005 by Children's Mercy Hospital Kansas City.
Recruitment status was:  Recruiting
Information provided by:
Children's Mercy Hospital Kansas City Identifier:
First received: September 13, 2005
Last updated: October 22, 2007
Last verified: August 2005
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.

Condition Intervention Phase
Hypophosphatemic Rickets, X-Linked Dominant
Drug: Cinacalcet
Phase 1

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Effect of Calcimimetic (Cinacalcet) on Phosphate-Induced Hyperparathyroidism in Children With Hypophosphatemic Rickets

Resource links provided by NLM:

Further study details as provided by Children's Mercy Hospital Kansas City:

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 ]

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 ]

Study Start Date: June 2005
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.


Ages Eligible for Study:   5 Years and older   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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
  Contacts and Locations
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Please refer to this study by its identifier: NCT00195936

Contact: Rachel Levy-Olomucki, MD 816-234-3010

United States, Missouri
Section of Pediatric Nephrology, Children's Mercy Hospitals and Clinics Recruiting
Kansas City, Missouri, United States, 64108
Principal Investigator: Rachel Levy-Olomucki, MD         
Sponsors and Collaborators
Children's Mercy Hospital Kansas City
Principal Investigator: Rachel Levy-Olomucki, MD Section of Pediatric Nephrology, Children's Mercy Hospitals and Clinics
  More Information Identifier: NCT00195936     History of Changes
Other Study ID Numbers: 05 02-027
Study First Received: September 13, 2005
Last Updated: October 22, 2007

Keywords provided by Children's Mercy Hospital Kansas City:
children and adolescents with hypophosphatemic rickets (XLH)

Additional relevant MeSH terms:
Rickets, Hypophosphatemic
Familial Hypophosphatemic Rickets
Bone Diseases, Metabolic
Bone Diseases
Musculoskeletal Diseases
Calcium Metabolism Disorders
Metabolic Diseases
Phosphorus Metabolism Disorders
Vitamin D Deficiency
Deficiency Diseases
Nutrition Disorders
Hypophosphatemia, Familial
Renal Tubular Transport, Inborn Errors
Kidney Diseases
Urologic Diseases
Metal Metabolism, Inborn Errors
Metabolism, Inborn Errors
Genetic Diseases, Inborn
Cinacalcet Hydrochloride
Calcimimetic Agents
Hormone Antagonists
Hormones, Hormone Substitutes, and Hormone Antagonists
Physiological Effects of Drugs processed this record on May 25, 2017