NCT03301038 · Children's Hospital of Philadelphia
Rifampin in CYP24A1-related Hypercalcemia and Hypercalciuria
(RICHH)
What this study is about
This study evaluates the effectiveness of rifampin in the treatment of hypercalcemia and/or hypercalciuria in participants with at least one inactivating mutation of the CYP24A1 gene. Eligible subjects will receive rifampin for a total of 16 weeks during this study.
View original scientific description
This study evaluates the efficacy of rifampin in the treatment of hypercalcemia and/or hypercalciuria in participants with at least one inactivating mutation of the CYP24A1 gene. Eligible subjects will receive rifampin for a total of 16 weeks during this study.
Interventions
DRUG
Rifampin
Rifampin 5 mg/kg (max 300 mg) daily for 8 weeks, followed by rifampin 10 mg/kg (max 600 mg) daily for 8 weeks.
Primary outcome measures
Serum albumin-adjusted calcium
Time frame: up to 32 weeks
Measured at baseline and every 4 weeks
Serum parathyroid hormone
Time frame: up to 32 weeks
Measured at baseline and every 4 weeks
Urinary calcium excretion
Time frame: up to 32 weeks
Measured at baseline and every 4 weeks
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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
- Philadelphia, Pennsylvania
Collaborators
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 22, 2026 · Source of record for eligibility and locations