Evaluation of Therapies for Secondary Hyperparathyroidism Associated with Vitamin D Insufficiency in Chronic Kidney Disease

<b><i>Introduction:</i></b> Parathyroid hormone-lowering responses after administration of three different therapies capable raising serum total 25-hydroxyvitamin D (25OHD) were evaluated in patients with secondary hyperparathyroidism (SHPT), vitamin insufficiency (VDI), and stage 3 or 4 chronic kidney disease (CKD). <b><i>Methods:</i></b> Sixty-nine adult subjects intact parathyroid hormone (iPTH) ≥85 <500 pg/mL VDI (25OHD <30 ng/mL) randomized ≥4-week washout to 2 months open-label treatment with: (1) extended-release calcifediol (ERC) 60 μg/day; (2) immediate-release (IRC) 266 μg/month; (3) high-dose cholecalciferol (HDC) 300,000 IU/month; (4) paricalcitol plus low-dose (PLDC) 1 μg 800 IU/day, used as reference replacement therapy. Serum 25OHD, calcium (Ca), phosphorus (P), plasma iPTH, adverse events monitored weekly. No clinically significant differences observed at baseline between groups. <b><i>Results:</i></b> Sixty-two completed the study per protocol (PP; 14–17 group). Mean (SD) 25OHD iPTH 20.6 (6.6) ng/mL 144.8 (90) pg/mL, respectively. increased end (EOT) 82.9 (17.0) ERC (<i>p</i> < 0.001) 30.8 (11.6) HDC 0.05), but remained unchanged IRC PLDC. EOT levels reached ≥30 all treated 44% HDC. All attained ≥50 versus none other therapies. response rates (≥10, 20 30% below baseline) similar for PLDC; much lower. changes from ionized corrected Ca P any group. One episode hypercalcemia (>10.3 mg/dL) occurred Hyperphosphatemia (>5.5 once ERC, eight times HDC, IRC, twice <b><i>Conclusion:</i></b> was highly effective both decreasing SHPT, VDI, CKD. iPTH-lowering daily PLDC, therapy; significantly is an attractive alternative therapy CKD patients.