Pharmacokinetics, Efficacy, and Safety of Encaleret in Pediatric Participants With Autosomal Dominant Hypocalcemia Type 1 (ADH1)

Key Inclusion Criteria: * Provide written informed consent (if legally permitted), or have written informed consent from a parent/legal guardian and provide assent (where required and as appropriate per local requirements) * Have a documented pathogenic or likely pathogenic activating variant, or variant of uncertain significance of the calcium-sensing receptor (CASR), associated with biochemical findings of hypoparathyroidism at screening or a documented history of hypoparathyroidism as manifested by hypocalcemia and intact parathyroid hormone (PTH) \<40 picogram per milliliter (pg/mL) (4.2 picomoles per liter \[pmol/L\]) * Have at least 1 symptom or sign of hypoparathyroidism at screening or a documented history of symptoms or signs of hypoparathyroidism * Be on ADH1 treatment for at least 6 months before screening for cohorts 1 to 3, or for at least 3 months before screening for cohort 4 Key Exclusion Criteria: * History of thyroid or parathyroid surgery * History of renal transplantation * History of cancer (except thyroid cancer, basal cell skin cancer, or squamous cell skin cancer), skeletal malignancies, bone metastases, irradiation (radiotherapy) to the skeleton, chemotherapy with alkylating agents, Paget disease, fibrous dysplasia, chronic osteomyelitis, bone infarcts, benign bone tumors with curettage and bone grafts, retinoblastoma, or Li-Fraumeni syndrome within 5 years before screening * Received any investigational medicinal product within 30 days or 5 half-l…