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Iron Therapy for Autosomal Dominant Hypophosphatemic Rickets: A Pilot Project.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02233322
Recruitment Status : Completed
First Posted : September 8, 2014
Last Update Posted : November 14, 2019
Information provided by (Responsible Party):
Michael Econs, Indiana University

Brief Summary:
The purpose of the study is to gain a better understanding of the effect of iron on fibroblast growth factor 23 (FGF23) in the inherited disorder, autosomal dominant hypophosphatemic rickets (ADHR). ADHR is an inherited disorder in which the body makes too much FGF 23 and causes low blood phosphorus levels and bone problems such as rickets (bowed legs in children) or bone pain and weakness in adults. This study is to test whether or not giving iron helps correct the high FGF23 and there by correcting the phosphate problem.

Condition or disease Intervention/treatment Phase
Autosomal Dominant Hypophosphatemic Rickets Dietary Supplement: Iron Not Applicable

Detailed Description:

Iron will be provided in an open label treatment to all enrolled subjects. Iron levels will be monitored in blood and doses adjusted with the target of getting the iron levels to or a little above 100 mcg/dl.

The study will look to see if there is a decrease of FGF23 level. It will also look at how long does it take to decrease the level of FGF 23 and how long it takes for the serum and urine phosphate to normalize.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 8 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Other
Official Title: Iron Therapy for Autosomal Dominant Hypophosphatemic Rickets: A Pilot
Study Start Date : August 2014
Actual Primary Completion Date : November 12, 2019
Actual Study Completion Date : November 12, 2019

Arm Intervention/treatment
Experimental: iron supplements
all subjects will receive iron supplementation based on iron levels in blood
Dietary Supplement: Iron
All subjects will receive iron supplementation based on iron levels in the blood
Other Names:
  • Ferrous Sulfate
  • Ferrous Gluconate

Primary Outcome Measures :
  1. Does increasing serum iron concentrations above 100 mcg/dl in patients with ADHR result in a decrease in intact FGF23. [ Time Frame: FGF23 will be measured at 1, 2, 3, 6, 9, and 12 months ]
    Perform a pilot study in ADHR patients with low serum iron concentrations (defined below) to determine if increasing serum iron concentrations above 100 mcg/dl results in a decrease in intact FGF23 (primary endpoint) and C-terminal FGF23 concentrations by at least 20% and normalizes serum phosphorus and TMP/GFR (tubular maximum phosphate reabsorption/ glomerular filtration rate) within 6 months of attaining goal iron concentrations.

Information from the National Library of Medicine

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Ages Eligible for Study:   25 Months and older   (Child, Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • FGF Mutation in either Arginine 176 or arginine 179
  • able and willing to provide consent or have a parent that is able/willing to consent, if a minor
  • either serum iron <50mcg/dl (regardless of phosphate or intact FGF23 concentration); or iron between 500 and 100mcg/dl with serum phosphorus value below 3.0mg/dl for adults or less than or equal to 0.5 mg/dl the lower limit of normal for age in children and intact FGF23 about 30pg/ml
  • age >2 years
  • May be receiving treatment with phosphate and calcitriol, but must be willing to undergo dose adjustments by the investigators if iron resolves the phosphate wasting defect.

Exclusion Criteria:

  • malignancy within the last 5 years, except treated squamous or basal cell skin carcinoma
  • terminal illness/hospice.
  • severe end-organ disease, e.g. cardiovascular, pulmonary, etc, which may limit ability to complete study.

estimated GFR <45ml/min/1.73m2, calculated using MDRD formula for adults or modified Schwartz equation for children

  • pregnancy or plan on becoming pregnant

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02233322

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United States, Indiana
Indiana University School of Medicine
Indianapolis, Indiana, United States, 46202
Sponsors and Collaborators
Indiana University
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Principal Investigator: Michael Econs, M.D. Indiana University School of Medicine
Sabbagh, Y., Tenenhouse HS, Econs, MJ, Mendelian Hypophosphatemias, in The Metabolic and Molecular Basis of Inherited Disease, C.R.S.e. al, Editor. 2008, McGraw-Hill: New York.
White, K.E. and M.J. Econs, Fibroblast growth factor-23 (FGF23), in Primer on the Metabolic Bone Diseases and Disorders of Mineral Metabolism. 2013, Wiley-Blackwell. p. 188-194.
The ADHR Consortium: Group 1:White, K.E., E.W., O'Riordan JLH, Speer MC, Econs MJ. Group 2: Lorenz-Depiereux B, Grabowski M, Meitinger T, Strom TM., Autosomal dominat hypophospataemic rickets is associated with mutations in FGF23. Nat Genet, 2000. 26(3): p. 345-8.

Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Michael Econs, Professor of Endocrinology and Metabolism, Indiana University Identifier: NCT02233322    
Other Study ID Numbers: IRON/ADHR
First Posted: September 8, 2014    Key Record Dates
Last Update Posted: November 14, 2019
Last Verified: November 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Yes
Keywords provided by Michael Econs, Indiana University:
Additional relevant MeSH terms:
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Rickets, Hypophosphatemic
Familial Hypophosphatemic Rickets
Joint Diseases
Musculoskeletal Diseases
Muscular Diseases
Musculoskeletal Abnormalities
Congenital Abnormalities
Bone Diseases, Metabolic
Bone Diseases
Metabolic Diseases
Calcium Metabolism Disorders
Vitamin D Deficiency
Deficiency Diseases
Nutrition Disorders
Phosphorus Metabolism Disorders
Hypophosphatemia, Familial
Renal Tubular Transport, Inborn Errors
Kidney Diseases
Urologic Diseases
Metal Metabolism, Inborn Errors
Metabolism, Inborn Errors
Genetic Diseases, Inborn
Ferrous gluconate