Calcimimetics in CKD - results from recent clinical studies

Secondary hyperparathyroidism (sHPT) is a frequent complication in patients with chronic kidney disease (CKD) and a known contributor to the development of vascular calcification and renal osteodystrophy (CKD-BMD). Secondary hyperparathyroidism is also related to increased cardiovascular mortality in CKD patients. With the discovery that molecules can modulate the calcium-sensing receptor (CaR) of the parathyroid gland, new treatment options are now available to control sHPT. Calcimimetics activate the CaR and-by increasing its sensitivity to calcium-can effectively decrease parathyroid hormone (PTH) secretion. Calcimimetic treatment with cinacalcet has resulted in an effective lowering of PTH levels in both animal and clinical studies. Most clinical studies have been performed in dialysis patients, and only a few studies have been carried out in patients with CKD stage 3 & 4 and renal transplant patients. In haemodialysis patients with sHPT, cinacalcet treatment could increase the number of patients achieving National Kidney Foundation Kidney Disease Outcomes Quality Initiative targets (PTH, calcium, phosphate) compared to standard therapy. In stage 3 and 4 CKD patients, cinacalcet has been reported to reduce PTH levels, however, at the expense of increasing phosphate serum levels. Several small studies have reported that calcimimetics reduced PTH levels and hypercalcaemia after renal transplantation. In addition, two studies on paediatric dialysis patients with sHPT reported effective PTH lowering. This review summarizes recent clinical studies with cinacalcet treatment in CKD patients.