Researchers observed no clinically relevant changes in vitamin D levels in dialysis patients with hyperphosphatemia treated with PA21, a novel iron-based phosphate binder, according to a poster presentation at the National Kidney Foundation’s 2014 Spring Clinical Meetings in Las Vegas.
In a randomized, open-label, phase 3 study, researchers led by Anjay Rastogi, MD, of the University of California Los Angeles Medical Center, compared PA21, to sevelamer (SEV). They studied 1,059 patients who were randomized to either PA21 or SEV for 12 weeks’ dose titration followed by 12 weeks of maintenance. All patients were 18 years or older and had been taking phosphate binders for at least a month.
Among those patients, 549 (322 on PA21, 227 on SEV) were then enrolled in a 28-week extension study to observe serum concentration changes in calcifediol, calcitriol, intact parathyroid hormone (iPTH) and total calcium.
Mean serum levels of calcifediol increased significantly by 0.9 ng/mL with PA21 and decreased significantly by 1.1 ng/mL with SEV. The investigators observed no significant differences in calcitriol or calcium levels between the two groups. Patients on SEV experienced a greater increase in iPTH compared with those on PA21.