Cinacalcet Treatment of Primary Hyperparathyroidism: Biochemical and Bone Densitometric Outcomes in a Five-Year Study

Context: Primary hyperparathyroidism (PHPT) is characterized by chronically elevated serum calcium and inappropriately normal or increased PTH. Objective: Our objective was to evaluate long-term tolerability, safety, and efficacy of cinacalcet in PHPT patients. Design and Setting: A 4.5-yr open-label extension study was conducted at 14 study centers in the United States. Patients or Other Participants: Forty-five subjects with PHPT from a double-blind, placebo-controlled, 1-yr trial were continued into this study. Interventions: After the parent study, all subjects were treated with 30 mg cinacalcet twice daily, increasing to 50 mg twice daily during the 12-wk titration if serum calcium levels were 10.3 mg/dl or higher and then maintained on cinacalcet for up to 4.5 yr. Main Outcome Measures: Assessments included serum calcium, PTH, phosphate and alkaline phosphatase, and areal bone mineral density (aBMD). Vital signs, safety chemistries and hematology, and adverse events were monitored throughout. Result...