Effects of the calcimimetic cinacalcet HCl on cardiovascular disease, fracture, and health-related quality of life in secondary hyperparathyroidism

Background. Secondary hyperparathyroidism (HPT) and abnormal mineral metabolism are thought to play an important role in bone and cardiovascular disease in patients with chronic kidney disease. Cinacalcet, a calcimimetic that modulates the calcium-sensing receptor, reduces parathyroid hormone (PTH) secretion and lowers serum calcium and phosphorus concentrations in patients with end-stage renal disease (ESRD) and secondary HPT. Methods. We undertook a combined analysis of safety data (parathyroidectomy, fracture, hospitalizations, and mortality) from 4 similarly designed randomized, double-blind, placebo-controlled clinical trials enrolling 1184 subjects (697 cinacalcet, 487 control) with ESRD and uncontrolled secondary HPT (intact PTH >= 300 pg/mL). Cinacalcet or placebo was administered to subjects receiving standard care for hyperphosphatemia and secondary HPT (phosphate binders and vitamin D). Relative risks (RR) and 95% CI were calculated using proportional hazards regression with follow-up times from 6 to 12 months. Health-related quality-of-life (HRQOL) data were obtained from the Medical Outcomes Study Short Form-36 (SF-36), and the Cognitive Functioning scale from the Kidney Disease Quality of Life instrument (KDQOL-CF). Results. Randomization to cinacalcet resulted in significant reductions in the risk of parathyroidectomy (RR 0.07, 95% CI 0.01-0.55), fracture (RR 0.46, 95% CI 0.22-0.95), and cardiovascular hospitalization (RR 0.61, 95% CI 0.43-0.86) compared with placebo. Changes in HRQOL favored cinacalcet, with significant changes observed for the SF-36 Physical Component Summary score and the specific domains of Bodily Pain and General Health Perception. Conclusion. Combining results from 4 clinical trials, randomization to cinacalcet led to significant reductions in the risk of parathyroidectomy, fracture, and cardiovascular hospitalization, along with improvements in self-reported physical function and diminished pain. These data suggest that, in addition to its effects on PTH and mineral metabolism, cinacalcet had favorable effects on important clinical outcomes.