Study: Minimal Risk of Iron Overload With Sucroferric Oxyhydroxide
Patients may need no more than routine evaluation of iron.
The long-term effect of sucroferric oxyhydroxide on iron parameters appears to be minimal, according to researchers.
Investigators led by Adrian C. Covic, MD, PhD, of Popa University in Romania, conducted a post hoc analysis of a 24-week phase 3 study of the iron-based phosphate binder sucroferric oxyhydroxide and its 28-week extension. Among 1059 hyperphosphatemia patients on hemodialysis or peritoneal dialysis, 710 were randomly assigned to sucroferric oxyhydroxide (1.0 to 3.0 g daily) and 349 to sevelamer carbonate (2.4 to 14.4 g daily) for up to 52 weeks. More than 70% of patients also received intravenous (IV) iron and/or erythropoiesis-stimulating agents (ESAs). Oral iron products were not permitted.
Both treatment groups experienced initial increases in mean transferrin saturation (TSAT) and ferritin that continued to a lesser degree for the duration of the year. During the first 24 weeks, increases in TSAT were slightly higher among sucroferric oxyhydroxide users (+4.6% vs +0.6%). Changes in hemoglobin were +1.6 vs −1.1 g/L, respectively.
Average ferritin concentrations, a reflection of iron stores, also initially increased through week 24 in both groups (+119 and +56.2 ng/mL for sucroferric oxyhydroxide and sevelamer, respectively) with no statistically significant difference between groups. To determine the impact of the phosphate binders alone, the investigators separately examined a subset of patients who did not receive IV iron. Ferritin concentrations declined from baseline in these patients, showing that IV iron was the driving factor.
Usage of anti-anemic products was similar between groups, with a trend toward higher use of IV iron and ESAs among sevelamer users, a greater percentage of whom were anemic.
“The risk of iron accumulation or overload with long-term sucroferric oxyhydroxide treatment appears to be minimal.”Dr Covic and colleagues wrote in Nephrology Dialysis Transplantation. “While minimal iron absorption from sucroferric oxyhydroxide may be beneficial to dialysis patients, who are often iron deficient, this treatment does not replace the use of IV iron products that enable controlled delivery of iron to replenish and maintain iron stores.”
Iron-related treatment-emergent adverse events were similar between groups, and none were serious, the investigators reported. Information on doses and frequency of IV iron and ESAs agents was lacking, which is a study limitation.
The study was funded by Vifor Pharma, makers of sucroferric oxyhydroxide (Velphoro®). The study authors disclosed fees from Vifor Pharma as well as other pharmaceutical companies.
1. Covic AC, Floege J, Ketteler M, et al. Iron-related parameters in dialysis patients treated with sucroferric oxyhydroxide. Nephrol Dial Transplant. 2016 Jun 23. doi: 10.1093/ndt/gfw242. [Epub ahead of print]