How phosphate therapy affects aging and the heart in XLH and HHRH

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

The study compares two groups of patients with hereditary hypophosphatemic rickets and related conditions, focusing on how long and how much phosphate therapy they have received. Researchers will use existing longitudinal data and add new measurements to assess renal and cardiovascular outcomes, including vascular function and heart imaging. The goal is to see whether prolonged or heavier phosphate treatment correlates with changes in kidney calcifications and cardiovascular markers. The study will also examine the short-term cardiovascular responses to phosphate loading. This work is conducted through a collaboration between pediatric and adult endocrinology at Yale, with support from NCATS.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* Children above the age of 13 years
* Younger and older adults with XLH and HHRH with confirmed NPT2c mutations affecting both copies of the NPT2c gene (HHRH) or one copy of the PHEX gene (XLH)
* Be willing to provide access to prior medical records to determine eligibility including imaging, biochemical, medical, and surgical history data
* Be willing and able to complete all aspects of the study
* Be willing to adhere to the study visit schedule and comply with the assessments (in the opinion of the investigator).

Exclusion Criteria:

* Subjects will be excluded, if they are children younger than age 13 years
* Subjects that have other diseases likely to impact bone and mineral metabolism (e.g. renal, hepatic, gastrointestinal disorders, and malignancy),
* Subjects that are currently pregnant,
* Subjects that received medical therapy or developed any condition, which in the opinion of the investigator, could present a concern for either subject safety or difficulty with data interpretation.
* Subjects will be excluded from Aim 2, if they are unable to tolerate supplemental phosphate.

Where it's running

• Yale University School of Medicine
  New Haven, Connecticut, United States Recruiting

Study contacts

• Principal investigator: Clemens Bergwitz, MD — Yale University
• Study coordinator: Clemens Bergwitz, MD
• Email: clemens.bergwitz@yale.edu
• Phone: 203-737-5450

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Enteral phosphate granules to treat low blood phosphate (hypophosphatemia)

  This trial will test whether giving enteral sodium dihydrogen phosphate and disodium hydrogen phosphate granules to adult ICU patients with low blood phosphate raises their serum phosphorus and is safe.

  Recruiting Union Hospital, Tongji Medical College, Huazhong University of Science and Technology · Wuhan, Hubei · NCT07233889

• Dipyridamole to prevent low phosphate after kidney transplant

  This study tests whether giving dipyridamole can help keep phosphate levels higher after a kidney transplant and reduce the need for phosphate supplements.

  Recruiting Phase 2 Stanford University · Stanford, California · NCT06824454

• Impact of low phosphate levels on weaning off mechanical ventilation

  This study is testing if giving a phosphate supplement can help patients with low phosphate levels breathe better and get off mechanical ventilation more easily.

  Recruiting Peking Union Medical College · Beijing · NCT06754670

• Using rifampin to treat hypercalcemia in patients with CYP24A1 mutations

  This study is testing if rifampin can help people with CYP24A1 mutations lower their high calcium levels and improve their health.

  Recruiting Phase 2 Children's Hospital of Philadelphia · Philadelphia, Pennsylvania · NCT03301038

• Phosphorus-31 Imaging to Explore Phosphate Diabetes in XLH

  This study tests phosphorus-31 spectroscopy to see if muscle and phosphate levels differ in people with phosphate diabetes (like XLH) compared with healthy peers.

  Recruiting Hospices Civils de Lyon · Bron and 1 other locations · NCT06921720

• Testing KK8123 in adults with X-linked hypophosphatemia

  This study is testing a new treatment called KK8123 to see if it can safely help adults with X-linked hypophosphatemia, a rare bone disease.

  Recruiting at 9 sites Phase 1/2 Kyowa Kirin Co., Ltd. · San Francisco, California and 9 other locations · NCT06525636

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.