Oral extended-release (ER) calcifediol is safe and effective for treating secondary hyperparathyroidism (SHPT) and vitamin D insufficiency in patients with chronic kidney disease, according to a new study published in the American Journal of Nephrology (2016;44:316-325).
Stuart M. Sprague, DO, of the NorthShore University Health System-University of Chicago Pritzker School of Medicine, Evanston, Illinois, and colleagues conducted 2 identical multicenter, randomized, double-blind, placebo-controlled studies that included a total of 429 patients with chronic kidney disease (CKD) stage 3 or 4, SHPT, and vitamin D insufficiency. The researchers randomly assigned patients 2:1 to receive oral ER calcifediol (30 or 60 µg) or placebo once daily at bedtime for 26 weeks. ER calcifediol is a novel vitamin D prohormone repletion therapy designed to gradually correct low serum total 25-hydroxyvitamin D and improve SHPT control, the investigators explained.
A total of 354 patients (83%) completed dosing and 298 (69%) entered a subsequent open-label extension study in which ER calcifediol was administered without interruption for another 26 weeks, the researchers stated.
ER calcifediol normalized serum total 25-hydroxyvitamin D levels (to concentrations above 30 ng/mL) in more than 95% of per-protocol patients and decreased plasma intact parathyroid hormone (iPTH) by at least 10% in 72% of patients, Dr Sprague and his collaborators reported. The proportion of patients receiving ER calcifediol who achieved iPTH reductions of 30% or more increased progressively with treatment duration, according to the investigators. The lowering of iPTH with ER calcifediol was independent of CKD stage and significantly greater compared with placebo. The effect of ER calcifediol on serum calcium, phosphorus, and fibroblast growth factor 23 was inconsequential, Dr Sprague and colleagues reported.