Cinacalcet HCl Reduces Hypercalcemia in Primary Hyperparathyroidism across a Wide Spectrum of Disease Severity

Abstract

CONTEXT: Primary hyperparathyroidism (PHPT) is characterized by elevated serum calcium (Ca) and increased PTH concentrations. OBJECTIVE: The objective of the investigation was to establish the efficacy of cinacalcet in reducing serum Ca in patients with PHPT across a wide spectrum of disease severity. DESIGN AND SETTING: The study was a pooled analysis of data from three multicenter clinical trials of cinacalcet in PHPT. PATIENTS: Patients were grouped into three disease categories for analysis based on the following: 1) history of failed parathyroidectomy (n = 29); 2) meeting one or more criteria for parathyroidectomy but without prior surgery (n = 37); and 3) mild asymptomatic PHPT without meeting criteria for either above category (n = 15). INTERVENTION: The intervention in this study was treatment with cinacalcet for up to 4.5 yr. OUTCOMES: Measurements in the study included serum Ca, PTH, phosphate, and bone-specific alkaline phosphatase, and areal bone mineral density (aBMD). Vital signs, safety biochemical and hematological indices, and adverse events were monitored throughout the study period. RESULTS: The extent of cinacalcet-induced serum Ca reduction, proportion of patients achieving normal serum Ca (≤10.3 mg/dl), reduction in serum PTH, and increase in serum phosphate were similar across all three categories. Except for decreased aBMD at the total femur indicated for parathyroidectomy group at 1 yr, no significant changes in aBMD occurred. The efficacy of cinacalcet was maintained for up to 4.5 yr of follow-up. AEs were mild and similar across the three categories. CONCLUSIONS: Cinacalcet is equally effective in the medical management of PHPT patients across a broad spectrum of disease severity, and overall cinacalcet is well tolerated.