Investigational drug restores parathyroid function in rare disease

Friday, October 13, 2023

Blood calcium levels normalized in clinical trial participants

An investigational drug, encaleret, restored calcium levels in people with autosomal dominant hypocalcemia type 1 (ADH1), a rare genetic disorder marked by an imbalance of calcium in the blood and urine, as well as abnormally low levels of parathyroid hormone, which regulates blood calcium levels. Led by clinician-scientists from the National Institute of Dental and Craniofacial Research (NIDCR) at the National Institutes of Health’s Clinical Center, results from the clinical trial are published in the New England Journal of Medicine.

In the mid-phase clinical trial, 13 participants with ADH1 received oral doses of the investigational drug for about 24 weeks. By the end of the trial, the treatment restored every participant’s blood calcium level to normal, and urine calcium approached normal levels. Levels of parathyroid hormone also normalized.

“It was amazing to see that every participant responded to the treatment. In literally minutes after taking the medication orally, the levels of parathyroid hormone increased dramatically,” said senior author and NIDCR endocrinologist Michael Collins, M.D.

NIDCR Senior Research Physician, Rachel I. Gafni, M.D., examines a clinical trial participant with ADH1, a rare genetic disorder marked by abnormally low levels of calcium in the blood.