Efficacy and safety study of cinacalcet for the treatment of hypercalcemia in patients with primary hyperparathyroidism unable to undergo parathyroidectomy

• age ≥ 18 years • diagnosis of primary hyperparathyroidism (HPT) • subjects must have the following laboratory values: 1. local/historical laboratory result showing a corrected total serum calcium > 1 mg/dL (0.25 mmol/L) above the upper limit of normal and ≤ 12.5 mg/dL (3.12 mmol/L) within the past 12 months, and - local/historical laboratory result showing a plasma parathyroid horone (PTH) > 75% of upper limit of normal within the past 12 months, and - one central laboratory draw at the screen visit showing a corrected total serum calcium > 11.3 mg/dL (2.82 mmol/L) and ≤ 12.5 mg/dL (3.12 mmol/L), and - one central laboratory draw at the screen visit showing a plasma PTH > 55 pg/mL (5.8 pmol/L) OR 2. two central laboratory draws performed during the screening period at least 7 days apart, showing a - corrected total serum calcium > 11.3 mg/dL (2.82 mmol/L) and ≤ 12.5 mg/dL (3.12 mmol/L), and - plasma PTH > 55 pg/mL (5.8 pmol/L) • not able to undergo parathyroidectomy for ≥ 1 of the following reasons: - failed parathyroidectomy - comorbid conditions contraindicating parathyroidectomy - parathyroidectomy not considered appropriate or is not feasible by primary physician and subject • before any study-specific procedure is performed, the appropriate written informed consent must be obtained

• symptoms attributable to hypercalcemia, requiring immediate medical intervention, as judged by the investigator (including acute kidney stone, nausea and vomiting requiring intravenous hydration, confusion, lethargy, stupor, or coma) • unstable medical condition, defined as having been hospitalized within 30 days before the date of informed consent, or otherwise unstable in the judgment of the investigator • administration of drugs that increase serum calcium concentration, including but not limited to thiazide diuretics or lithium • initiated bisphosphonate therapy or changed bisphosphonate dose within 12 weeks before the date of informed consent • current administration of drugs for ventricular arrhythmia • unable to provide informed consent, or is at risk for poor compliance with study procedures • currently enrolled in another investigational device or drug study(s), or completed such study within 30 days before the date of informed consent • known hypersensitivity to or unable to tolerate cinacalcet • received treatment with cinacalcet within 60 days before the date of informed consent • history of seizures or an adjustment of anti-seizure medication within 12 weeks before the date of informed consent • family history or diagnosis a genetic syndrome, such as familial benign hypocalciuric hypercalcemia (FBHH) or multiple endocrine neoplasia type 1 (MEN1) and type 2 (MEN2), where primary HPT is one of the clinical manifestations of familial benign hypocalciuric hypercalcemia (FBHH) • refused to use highly effective contraceptive measures (as determined by the investigator) throughout the study • pregnant or breastfeeding