Encaleret for Chronic Hypoparathyroidism: Testing if it helps symptoms and safety

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

This Phase 3 trial evaluates the efficacy, safety, and tolerability of orally administered encaleret versus placebo in adults with chronic hypoparathyroidism. Participants must have had the condition for at least 26 weeks and be on stable calcium and active vitamin D doses. Key eligibility includes various etiologies (postsurgical, autoimmune, genetic, or idiopathic) and, for non-surgical cases, absence of pathogenic CASR/GNA11 variants except common CASR polymorphisms. Sites are located in Reno, NV; Greenville, NC; and Morehead City, NC, under Calcilytix Therapeutics, Inc. as lead sponsor. Primary comparisons focus on symptom control and safety signals over treatment. Candidacy depends on meeting mineral supplementation thresholds and medical history requirements.

Why it matters

Who can join: the full rules

Key Inclusion Criteria:

* Participants must have had a clinically confirmed diagnosis of chronic HP, with disease duration of at least 26 weeks prior to screening. Cause of chronic HP can be postsurgical, autoimmune, genetic, or idiopathic.
* For participants with nonsurgical chronic HP etiology, sufficient documentation that the participant does not harbor any variants in calcium-sensing receptor (CASR) or GNA11 that are classified as pathogenic, likely pathogenic, or of uncertain significance, with the exception of benign common polymorphisms (CASR A986S and R990G) is needed.
* Participants must be on stable doses of calcium and active vitamin D supplementation at or above the following minimum thresholds for at least 6 weeks prior to screening.

For participants enrolled in study sites outside Japan:

* Calcitriol ≥0.5 micrograms (μg)/day or alfacalcidol ≥1.0 μg/day
* Elemental calcium ≥800 milligrams (mg)/day (for example, calcium citrate, calcium carbonate)
* Participants must meet the following criteria during screening: cCa within 7.8 to 9.5 mg/deciliter (dL) and 24-hour UCa ≥300 mg/day (males) or ≥250 mg/day (females).
* Participants have serum 25-hydroxy (OH) vitamin D concentration of 20 to 80 nanograms (ng)/milliliter (mL) (50-200 nanomoles \[nmol\]/liter \[L\]).
* Participants have serum magnesium concentration within the reference range.
* Participants on thiazide or loop diuretics must be able to discontinue them during the first 24 weeks of study (treatment).
* Participants must be capable of giving signed informed consent or assent, which includes compliance with the requirements and restrictions listed in the informed consent form and in this protocol.

Key Exclusion Criteria:

* Genetically confirmed diagnosis of autosomal dominant hypocalcemia type 1 (ADH1) or autosomal dominant hypocalcemia type 2 (ADH2) due to activating variants in CASR or GNA11, respectively.
* History of hypocalcemic seizure in the 3 months prior to screening.
* History of cancer (except thyroid cancer, non-melanoma skin cancer) or bone metastases in the 5 years prior to screening.
* Prior skeletal irradiation, chemotherapy with alkylating agents, or diagnosis of Paget's disease, fibrous dysplasia, chronic osteomyelitis, bone infarcts, benign bone tumors with curettage and grafting, retinoblastoma, or Li-Fraumeni syndrome.
* Presence or history of any disease or condition (for example, drug or alcohol dependence) that, in the view of the investigator, would affect the participant's safety or places the participant at high risk of poor treatment compliance or of not completing the study.

Other protocol-defined inclusion/exclusion criteria apply.

Where it's running

• Calcilytix Therapeutics, Inc., a BridgeBio Company, Investigational Site
  Reno, Nevada, United States Recruiting
• Calcilytix Therapeutics, Inc., a BridgeBio Company, Investigational Site
  Greenville, North Carolina, United States Recruiting
• Calcilytix Therapeutics, Inc., a BridgeBio Company, Investigational Site
  Morehead City, North Carolina, United States Recruiting
• Calcilytix Therapeutics, Inc., a BridgeBio Company, Investigational Site
  El Paso, Texas, United States Recruiting
• Calcilytix Therapeutics, Inc., a BridgeBio Company, Investigational Site
  Oakville, Ontario, Canada Recruiting

Study contacts

• Study coordinator: Medical Information
• Email: MedInfo@bridgebio.com
• Phone: 650-600-3610

Similar studies

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

• German Hypoparathyroidism Registry

  This registry in Germany collects information from adults with chronic hypoparathyroidism or pseudohypoparathyroidism to better understand how the condition affects people over time and to support future research.

  Recruiting University Hospital Augsburg · Augsburg, Bavaria · NCT07857460

• Palopegteriparatide in adolescents with long-term hypoparathyroidism

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• Canvuparatide vs placebo in adults with hypoparathyroidism

  This study tests whether weekly canvuparatide can help adults with hypoparathyroidism feel better and keep calcium levels steady compared with a placebo.

  Recruiting at 22 sites Phase 3 MBX Biosciences · Englewood, Colorado and 21 other locations · NCT07699471

• NIRAF-guided identification of parathyroids during thyroidectomy

  A wearable near-infrared autofluorescence device is being tested to help surgeons find and protect the parathyroid glands during thyroid surgery in adults.

  Recruiting Ss. Cyril and Methodius University of Skopje · Skopje · NCT07617584

• Pregnancy registry tracking outcomes after YORVIPATH exposure during pregnancy and breastfeeding

  This registry collects information from pregnant or breastfeeding people with hypoparathyroidism who took YORVIPATH to see if the exposure affects pregnancy, the baby, or infant outcomes through the first year of life.

  Recruiting Ascendis Pharma A/S · Morgantown, West Virginia · NCT07345494

• Palopegteriparatide levels in breast milk of lactating individuals taking YORVIPATH.

  This will see if palopegteriparatide (YORVIPATH) appears in the breast milk of lactating adults with hypoparathyroidism who are breastfeeding.

  Recruiting Ascendis Pharma A/S · Morgantown, West Virginia · NCT07264634

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.