Efficacy and safety of cinacalcet for the treatment of secondary hyperparathyroidism in patients with advanced chronic kidney disease before initiation of regular dialysis

Aim: To evaluate the compassionate use of cinacalcet for the management of secondary hyperparathyroidism in patients who are not on dialysis. Methods: Patients with stage 4-5 chronic kidney disease (CKD) who were not on dialysis, had an intact parathyroid hormone (iPTH) level greater than 300 pg/mL, and had not responded satisfactorily to treatment with phosphate binders and vitamin D were prospectively studied. Patients received 6 months of compassionate treatment with cinacalcet, which was initiated at a dose of 30 mg/day orally and flexibly dosed thereafter based on iPTH levels. Results: Twenty-six patients with a mean age +/- standard deviation (SD) of 58.8 +/- 16.1 years were enrolled in the study and included in the statistical analysis. The mean percentage change in iPTH levels from baseline after 6 months of treatment was -67.9 +/- 17.0%, with 92.3% (95% confidence interval (CI), 75.9-97.9) of patients showing an iPTH level within the limits recommended by Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines. The mean serum calcium concentrations had decreased significantly at the end of the study (-8.0 +/- 6.9%), while the mean serum phosphorus concentration had significantly increased (+ 8.3 +/- 17.0%). Conclusion: Our results suggest that cinacalcet may be a useful alternative for the treatment of secondary hyperparathyroidism in pre-dialysis patients who are unresponsive to other treatments. The hypocalcemia and hyperphosphatemia reported in previous studies may not occur if a moderate dose of calcimimetics is used in patients with marginal glomerular filtration rates, especially if combined with vitamin D analogues and calcium-based phosphate binders.