Using rifampin to treat hypercalcemia in patients with CYP24A1 mutations

Rifampin to Reduce Elevated Levels of Blood and Urine Calcium in Patients With Inactivating Mutations in the CYP24A1 Gene

Phase 2 Interventional Children's Hospital of Philadelphia · NCT03301038

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

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment60 (estimated)
Ages6 Months to 65 Years
SexAll
SponsorChildren's Hospital of Philadelphia Academic / other
Locations1 site (Philadelphia, Pennsylvania)
Trial IDNCT03301038 on ClinicalTrials.gov

What this trial studies

This study evaluates the effectiveness of rifampin in treating hypercalcemia and hypercalciuria in individuals with at least one inactivating mutation of the CYP24A1 gene. Participants aged 6 months to 65 years will receive rifampin for 16 weeks after an initial 8-week observation period, followed by an additional 8 weeks of monitoring. The study aims to assess the drug's impact on calcium homeostasis and its pharmacokinetics in this specific genetic condition. The approach is based on preliminary data suggesting that rifampin may enhance the metabolism of vitamin D metabolites through the induction of specific liver enzymes.

Who should consider this trial

Good fit: Ideal candidates include males and females aged 6 months to 65 years with at least one CYP24A1 mutation and elevated serum or urinary calcium levels.

Not a fit: Patients with significant drug interactions with rifampin or those who are pregnant or breastfeeding may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could significantly improve calcium regulation in patients with CYP24A1-related hypercalcemia.

How similar studies have performed: While this approach is novel, preliminary data suggest potential efficacy, but further validation is needed as similar studies have not been widely conducted.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Males or females age 6 months to 65 years.
* at least one mutations of CYP24A1
* Serum and/or urinary calcium above the normal reference range for age
* Serum PTH concentration \<20 pg/ml
* Elevated or normal serum concentration of 1,25-dihydroxyvitamin D3.

Exclusion Criteria:

* Parents/guardians or subjects who, in the opinion of the Investigator, may be non-compliant with study schedules or procedures.
* Allergy to rifampin or related medications
* Current therapies with medications that have significant drug-drug interactions with rifampin, defined as a medication considered to interact with CYP3A4 or CYP3A5 and either induce or inhibit expression or function of these P450 enzymes. By "drug-drug" interactions we are looking for medications that will affect metabolism or action of rifampin as exclusionary, not medications that will be affected by rifampin.
* Pregnancy or breastfeeding
* Laboratory abnormalities that indicate clinically significant hepatic, or renal disease:
* Aspartate Aminotransferase (AST/SGOT) \> 2.0 times the upper limit of normal Alanine aminotransferase (ALT/SGPT) \> 2.0 times the upper limit of normal Total bilirubin \> 2.0 times the upper limit of normal Creatinine \> 2.0 times the upper limit of normal

Where this trial is running

Philadelphia, Pennsylvania

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Idiopathic Infantile Hypercalcaemia - Severe FormGenetic DiseaseHypercalcemia, Idiopathic, of InfancyHypercalciuric HypercalcemiaIdiopathic Infantile Hypercalcemia - Mild FormHypercalciuriahypercalcemianephrocalcinosis
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.