Potential future uses of calcimimetics in patients with chronic kidney disease

Cinacalcet has proven effective in the treatment of secondary hyperparathyroidism (SHPT) in dialysis patients, and it may also have benefits in stage 3 and 4 chronic kidney disease (CKD). The efficacy of cinacalcet in the treatment of SHPT was investigated in a study of 54 patients with stage 3 and 4 CKD not receiving dialysis. A significant number of these patients achieved at least a 30% reduction in parathyroid hormone (PTH) from baseline with cinacalcet therapy compared with placebo (56% versus 19%; P = 0.006). Another potential use of cinacalcet is in the treatment of persistent hyperparathyroidism (HPT) after kidney transplantation. The pathophysiologic considerations for persistent HPT in patients who have undergone renal transplantation are different from those in stage 3 and 4 CKD. Post-transplant patients with normal graft function often present with hypercalcaemia, low serum phosphorus and persistently elevated levels of PTH. In eight small open-label studies including a total of 83 patients with persistent HPT after successful kidney transplantation, cinacalcet treatment effectively corrected hypercalcaemia and significantly reduced elevated PTH levels. These studies suggest that cinacalcet therapy is an effective therapy in controlling hyperparathyroidism in patients with stage 3 and 4 CKD and in post-transplant patients with persistent hyperparathyroidism.