ASN's Mission

To create a world without kidney diseases, the ASN Alliance for Kidney Health elevates care by educating and informing, driving breakthroughs and innovation, and advocating for policies that create transformative changes in kidney medicine throughout the world.

learn more

Contact ASN

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

email@asn-online.org

202-640-4660

The Latest on X

Kidney Week

Abstract: TH-PO1152

Control of Secondary Hyperparathyroidism with Extended-Release Calcifediol Is Associated with Slower CKD Progression

Session Information

  • Late-Breaking Posters
    November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
    Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

  • 2302 CKD (Non-Dialysis): Clinical, Outcomes, and Trials

Authors

  • Bishop, Charles W., OPKO Health Inc, Miami, Florida, United States
  • Strugnell, Stephen A., OPKO Health Inc, Miami, Florida, United States
  • Ashfaq, Akhtar, OPKO Health Inc, Miami, Florida, United States
Background

Insufficient levels of serum total 25-hydroxyvitamin D (25D) increase the risk of secondary hyperparathyroidism (SHPT) in patients with stage 3 or 4 chronic kidney disease (CKD). SHPT develops and advances in most CKD patients because 25D is not reliably raised with cholecalciferol or ergocalciferol. SHPT is associated with accelerated CKD progression and dialysis onset, but mitigation of disease progression by effective control of SHPT has not been previously examined.

Methods

Progressive changes in estimated glomerular filtration rate (eGFR) were examined post-hoc in 166 patients with vitamin D insufficiency, SHPT and stage 3-4 CKD during 1-year of treatment with extended-release calcifediol (ERC) in pivotal trials (Sprague 2016). ERC was administered daily at 30 mcg increasing, as needed, after 12 weeks to 60 mcg to achieve a targeted ≥30% reduction in iPTH. Measurements of eGFR were obtained at baseline (BL) and quarterly intervals, and 25D (DiaSorin), calcium (Ca), phosphorus (P) and plasma intact parathyroid hormone (iPTH; Roche Elecsys) at BL and monthly. Mean BL or quarterly iPTH levels of ≤100 pg/mL were considered “controlled” and, if maintained at 4 of these 5 assessments, “consistently controlled”.

Results

ERC treatment increased mean (±SE) serum 25D from 20.1±0.4 ng/mL at BL to 77.8±2.0 at end of treatment (EOT; p<0.001) and decreased mean iPTH from 146.6±4.7 pg/mL at BL to 104.4±6.5 at EOT (p<0.01) without clinically meaningful changes in mean serum Ca or P. Decreases in mean iPTH were unaffected by BL eGFR. Average eGFR decline was 2.3±0.5 mL/min/1.73m2 over the 1-year treatment period but differed significantly and proportionally with duration of iPTH control, being maximal (4.1±0.7) in subjects who never achieved control (n=44) and minimal (0.61±1.2) in subjects achieving consistent control (n=51; p<0.05). The number of subjects achieving an increase in eGFR by EOT rose in proportion to the duration of iPTH control achieved from 6 (no control) to 18 (consistent control).

Conclusion

A post-hoc analysis of pivotal clinical trial data with ERC indicates that early, sustained, effective treatment of SHPT is associated with mitigation of eGFR decline in patients with insufficient 25D and stage 3-4 CKD. Prospective studies with ERC are warranted to confirm these findings.

Funding

  • Commercial Support – OPKO Health