[Is denosmab really effective and safe in the care of CKD-MBD?].

The authors of Freedom study enrolling primary osteoporosis patients argued that the anti-fracture effect of denosmab is not dependent on baseline estimated glomerular filtration rate(eGFR)by showing the non-significant interaction term between treatment and CKD stage. However, given disproportionate numbers of patients in each subgroup(4069, 2817, and only 73 patients, in CKD stage 2, 3, and, 4, respectively), this study seems to lack the statistical power to reach a definite conclusion on the effect modification by CKD stage. Truly, the serum concentration of infused denosmab in patients with CKD stage 4 is equivalent to that in patients without CKD, the risk of developing life-threatening or prolonged hypocalcemia is huge even under active vitamin D therapy in this population. In hemodialysis patients, this drug is relatively safer because each dialysis session delivers calcium into the circulation 3 times a week. However, even with concomitant administration of massive active vitamin D, the increase of intact PTH levels greater than 1000 pg/mL by this agent is not rare. In other words, this drug worsens secondary hyperparathyroidism. Moreover, reportedly, calcium and active vitamin D administered to avoid hypocalcemia can lead to ectopic calcification especially under the low bone turnover induced by this agent. In fact, transient hypercalcemia often follows hypocalcemia by the inevitable calcium supplementation.