Cinacalcet hydrochloride is an effective treatment for secondary hyperparathyroidism in patients with CKD not receiving dialysis.

BACKGROUND

Secondary hyperparathyroidism develops early in patients with chronic kidney disease (CKD). Clinical guidelines from the National Kidney Foundation-Kidney/Disease Outcomes Quality Initiative emphasize the need to control parathyroid hormone (PTH), calcium, and phosphorus levels in patients with CKD not receiving dialysis to reduce poor outcomes. This phase 2 study evaluated the effects of the oral calcimimetic cinacalcet hydrochloride in patients with CKD not on dialysis therapy.

METHODS

A randomized, double-blind, placebo-controlled, 18-week study enrolled adults with an estimated glomerular filtration rate of 15 to 50 mL/min/1.73 m2 (0.25 to 0.83 mL/s/1.73 m2) and an intact PTH (iPTH) level greater than 130 pg/mL (ng/L). Cinacalcet (or placebo) was titrated from 30 to 180 mg once daily to obtain a 30% or greater reduction in iPTH levels from baseline.

RESULTS

Baseline mean iPTH levels were 243 pg/mL (ng/L) in the cinacalcet group (n = 27) and 236 pg/mL (ng/L) in the control group (n = 27). At baseline, 28% of subjects were being administered vitamin D sterols and 43% were being administered phosphate binders or calcium supplements. The addition of cinacalcet significantly decreased iPTH concentrations compared with controls during the efficacy-assessment phase: 56% versus 19% of subjects achieved a 30% or greater reduction in iPTH levels (P = 0.006), and mean iPTH levels decreased by 32% in the cinacalcet group, but increased by 6% in the control group (P < 0.001). Mean serum calcium and phosphorus levels remained within normal range throughout the study. Cinacalcet generally was well tolerated; the most frequent adverse events were gastrointestinal.

CONCLUSION

This preliminary study provides evidence that cinacalcet is efficacious for the treatment of secondary hyperparathyroidism in subjects with CKD not receiving dialysis.