ASN's Mission

ASN leads the fight to prevent, treat, and cure kidney diseases throughout the world by educating health professionals and scientists, advancing research and innovation, communicating new knowledge, and advocating for the highest quality care for patients.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005


The Latest on Twitter

Kidney Week

Abstract: PO0565

Comparison of Extended-Release Calcifediol (ERC), Immediate-Release Calcifediol, Cholecalciferol, and Paricalcitol for Treating Secondary Hyperparathyroidism (SHPT) in CKD

Session Information

Category: CKD (Non-Dialysis)

  • 2102 CKD (Non-Dialysis): Clinical, Outcomes, and Trials


  • Strugnell, Stephen A., OPKO Health Inc., Miami, Florida, United States
  • Spiegel, David M., Vifor Pharma Ltd, Zurich, Switzerland
  • Csomor, Philipp, Vifor Pharma Ltd, Zurich, Switzerland
  • Ashfaq, Akhtar, OPKO Health Inc., Miami, Florida, United States
  • Bishop, Charles W., OPKO Health Inc., Miami, Florida, United States

Serum total 25-hydroxyvitamin D (25D) levels above 50.8 ng/mL are required to produce meaningful and progressive reductions in plasma intact parathyroid hormone (iPTH) in patients with stages 3 or 4 CKD [Strugnell et al 2019]. The current study compared the abilities of four treatment regimens to increase serum 25D to this level and to reduce iPTH in this population.


Subjects with stage 3 or 4 CKD, SHPT (iPTH ≥85 and <500 pg/mL) and vitamin D insufficiency (25D <30 ng/mL) underwent an 8-week washout from previous vitamin D therapies and were randomized to 60 days of open-label treatment with: 1) ERC 60 mcg/day; 2) immediate-release calcifediol (IRC) 266 mcg/month; 3) high-dose cholecalciferol (HDC) 300,000 IU/month; or 4) paricalcitol plus low-dose cholecalciferol (PLDC) 1 mcg and 800 IU/day. Paricalcitol was increased to 2 mcg/day after 30 days if iPTH was not reduced by 30% and safety parameters allowed. Subjects were monitored for changes in serum 25D, calcium (Ca) and phosphorus (P), and plasma iPTH.


Mean (SD) post-washout/pre-treatment baseline levels for 25D and iPTH in the per-protocol population were 20.6 (6.6) ng/mL and 145 (90) pg/mL, respectively. No differences were observed at baseline between treatment groups (14-17 subjects each). At the end of treatment, mean 25D (ng/mL) increased to 82.9 (17.0) with ERC (P<0.05), 30.8 (11.6) with HDC (P<0.05), 26.3 (6.8) with IRC and 24.2 (7.3) with PLDC. All subjects treated with ERC attained 25D levels ≥30 ng/mL vs. only 44% with HDC (P<0.001), 20% with IRC and 14% with PLDC. Most ERC subjects (94%) attained 25D levels >50.8 ng/mL. The proportion of subjects who achieved at least a 20% reduction in iPTH were 71% with ERC, 38% with HDC, 20% with IRC and 79% with PLDC. No changes from baseline were observed in mean Ca or P in any treatment group, but one instance of hypercalcemia (>10.3 mg/dL) was observed with PLDC treatment.


ERC was safe and more effective at increasing serum 25D and decreasing plasma iPTH than IRC, HDC or PLDC in patients with SHPT, vitamin D insufficiency, and stage 3 or 4 CKD.


  • Commercial Support