Efficacy, Safety, and Tolerability of Encaleret in Participants With Chronic Hypoparathyroidism
Purpose
The aim of the study is to evaluate the efficacy, safety, and tolerability of orally administered encaleret tablets in participants with chronic hypoparathyroidism (HP).
Conditions
- Hypoparathyroidism
- Chronic Hypoparathyroidism
Eligibility
- Eligible Ages
- Over 16 Years
- Eligible Sex
- All
- Accepts Healthy Volunteers
- No
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 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: 1. Calcitriol ≥0.5 micrograms (μg)/day or alfacalcidol ≥1.0 μg/day 2. 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.
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 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.
Study Design
- Phase
- Phase 3
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel Assignment
- Primary Purpose
- Treatment
- Masking
- Double (Participant, Investigator)
- Masking Description
- The treatment period will be double-blind. The long-term extension period will be open-label.
Arm Groups
| Arm | Description | Assigned Intervention |
|---|---|---|
|
Experimental Encaleret |
Participants will receive encaleret during the 24-week double-blind treatment period. Participants will then have the option to enter an open-label long-term extension (LTE) period to continue receiving encaleret for up to 192 weeks. |
|
|
Placebo Comparator Placebo |
Participants will receive placebo during the 24-week double-blind treatment period. Participants will then have the option to enter an open-label LTE period to receive encaleret for up to 192 weeks. |
|
Recruiting Locations
Calcilytix Therapeutics, Inc., a BridgeBio Company, Investigational Site
Reno, Nevada 89511
Reno, Nevada 89511
Calcilytix Therapeutics, Inc., a BridgeBio Company, Investigational Site
Greenville, North Carolina 27834
Greenville, North Carolina 27834
Calcilytix Therapeutics, Inc., a BridgeBio Company, Investigational Site
Morehead City, North Carolina 28557
Morehead City, North Carolina 28557
Calcilytix Therapeutics, Inc., a BridgeBio Company, Investigational Site
El Paso, Texas 79935
El Paso, Texas 79935
More Details
- Status
- Recruiting
- Sponsor
- Calcilytix Therapeutics, Inc., a BridgeBio company