Impact of cinacalcet introduction on MBD management: the MBD-5D study in Japan

Chronic kidney disease-mineral and bone disorder (CKD-MBD) has recently attracted attention in light of its association with clinical outcomes, such as fracture, cardiovascular disease, and mortality. Management of CKD-MBD has therefore come to have a central role in dialysis practice. Cinacalcet, a newly developed drug, has changed prescription patterns in many centers based on different changes in MBD markers than those observed with active vitamin D derivatives. As physicians require real-world evidence to guide their treatment decisions with respect to MBD management, we conducted the Mineral and Bone Disorder Outcomes Study for Japanese CKD Stage 5D Patients (MBD-5D), a 3-year observational study involving prevalent hemodialysis patients with secondary hyperparathyroidism (SHPT). Here, we review the results from the MBD-5D and discuss issues of MBD management in the cinacalcet era. Three years since the introduction of cinacalcet, 40% of hemodialysis patients with SHPT have come to use cinacalcet, enjoying marked improvement in management of circulating MBD markers, such as intact parathyroid hormone (PTH), phosphorus, and calcium. Combination therapy with cinacalcet and a vitamin D receptor activator (VDRA) may allow physicians to choose more suitable prescription patterns based on patient characteristics and therapeutic purposes. We observed an additive association between 'starting cinacalcet' and 'increased VDRA dose,' with marked improvement in the control of intact PTH levels. Further, the combination pattern of 'starting cinacalcet' and 'decreased VDRA dose' was associated with better achievement of target serum phosphorus and calcium levels. Future studies should examine the effect of different prescription patterns for SHPT treatment on clinical outcomes.