Rifampin to lower high blood and urine calcium in people with CYP24A1 mutations

Repurposing rifampin to reduce elevated levels of blood and urine calcium in patients with inactivating mutations of CYP24A1

NIH-funded research Children's Hosp of Philadelphia · NIH-11235183

People with CYP24A1 gene mutations who have high blood or urine calcium are given the antibiotic rifampin to try to lower calcium and protect the kidneys.

Quick facts

Grant typeR01 grant
Study typeNIH-funded research
Funding institutionChildren's Hosp of Philadelphia NIH-funded
Lab location1 site (Philadelphia, United States)
Project IDNIH-11235183 on NIH RePORTER

What this research studies

This is a phase IIa clinical trial extension that gives the approved antibiotic rifampin to people with mutations in CYP24A1 that cause lifelong problems breaking down active vitamin D. Participants take rifampin under medical supervision and have regular blood and urine tests to measure calcium and active vitamin D levels, plus monitoring of kidney function and safety labs. The team will compare each participant's results to their baseline and track kidney stone risk and any side effects over time. The goal is to see whether rifampin can sustainably reduce calcitriol-driven calcium elevations with acceptable safety.

Who could benefit from this research

Good fit: Ideal candidates are people with genetically confirmed CYP24A1 mutations who have persistently high blood or urine calcium, recurrent kidney stones, or declining kidney function related to hypercalciuria.

Not a fit: People without CYP24A1 mutations, those whose high calcium is due to other causes, and anyone who cannot take rifampin because of liver disease, pregnancy, or major drug interactions are unlikely to benefit.

Why it matters

Potential benefit: If successful, rifampin could become an available treatment to lower calcium levels and reduce kidney stones and kidney damage in people with CYP24A1-related hypercalcemia.

How similar studies have performed: Small early-phase trials and case reports have suggested rifampin can lower active vitamin D and urinary calcium in patients with CYP24A1 mutations, but larger controlled data are still limited.

Where this research is happening

Philadelphia, United States

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.
Last reviewed 2026-06-10 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.