Hyperphosphataemia leads to the development of chronic kidney disease–mineral and bone disorder (CKD–MBD), which increases morbidity and mortality in patients with CKD. Aside from dietary restrictions and adequate haemodialysis, phosphate binders play a crucial role in hyperphosphataemia management. At an industry-sponsored symposium during the 29th Hong Kong Medical Forum, Professor Li Zuo of the Peking University People's Hospital in Beijing, China, discussed the advantages of sucroferric oxyhydroxide (SO; Velphoro®, Rxilient) vs other phosphate binders, highlighting its high phosphate-binding capacity, reduced pill burden, and potential benefits for longterm disease control and adherence in patients with CKD–MBD.
Phosphate binders central to hyperphosphataemia management
Since maintaining phosphorus-restricted diets is challenging, phosphate binders (usually taken with meals) have become an important strategy to decrease bioaccessibility of phosphorus, as well as concomitantly reduce absolute intestinal phosphorus absorption in patients with CKD–MBD. [Nephron 2024;148:22- 33; Nutrients 2018;10:1364]
Phosphate binders are associated with improved survival in new haemodialysis patients. Non-calcium–based formulations are shown to significantly reduce all-cause mortality in CKD patients, and are thus recognized by guidelines as preferred first-line phosphate-lowering agents. [J Am Soc Nephrol 2009;20:388-396; Lancet 2013;382:1268-1277; Kidney Int Suppl 2017;7:1-59; Kidney Dis (Basel) 2019;5:197-203]
Advantages of SO as phosphate binder
“An ideal phosphate binder should have high phosphate-binding capacity, minimal side effects, low pill burden, easy administration, no systemic absorption, and minimal physiological impact,” opined Zuo. [J Ren Nutr 2016;26:209-218; J Ren Nutr 2021;31:21-34]
“Among currently available phosphate binders, the oral, non-calcium, iron-based drug, SO [‘special drug’ listed in the Hospital Authority’s Drug Formulary with effect from 26 April 2025], demonstrates exceptional phosphate-binding efficiency, is well tolerated, and is a convenient alternative to conventional phosphate binders like sevelamer.” [Velphoro Hong Kong Prescribing Information; www.ha.org. hk/hadf/Portals/0/Docs/HADF_List/ External%20list%2020190413/9%20 %20%20NUTRITION%20AND%20 BLOOD.pdf; J Ren Nutr 2021;31:21-34; J Ren Nutr 2016;26:209-218; Nephron 2024;148:22-33]
Improved binding capacity, reduced pill burden, increased adherence
In terms of phosphate-binding capacity, SO is 2.6 times more potent than sevelamer. [J Ren Nutr 2021;31:21-34] This greater potency translates to reduced pill burden, as demonstrated in a randomized, open-label, 12-week, phase III study involving Chinese dialysis patients with hyperphosphataemia (n=286). Results showed that patients who received SO required a mean of only 3.7 pills daily during the maintenance phase vs 9.1 pills for those on sevelamer. [Nephron 2024;148:22-33]
“This may also translate to improved long-term medication adherence,” said Zuo. “In a phase III extension study, adherence rates reached 86.2 percent for dialysis patients with hyperphosphataemia maintained on SO vs 76.9 percent for those on sevelamer.” [Nephrol Dial Transplant 2015;30:1037-1046]
In terms of long-term efficacy, a real-world study showed that the proportion of SO-treated patients achieving optimal target serum phosphate levels of ≤5.5 mg/dL increased steadily over time, from 29.9 percent at baseline to 63.0 percent at 30 months of treatment. (Figure 1) [Clin Kidney J 2021;14:1770-1779]
“Importantly, at least half of the patients achieved and maintained the target phosphate level of ≤5.5 mg/dL after 3 months,” highlighted Zuo. (Figure 1) [Clin Kidney J 2021;14:1770-1779] “This early decrease in phosphate levels after initiating SO is a common observation in our clinical practice.”
Safety profile and nutritional benefits
In the same real-world study, SO’s safety and tolerability were consistent with its known safety profile from previous studies, with no new safety signals reported. Diarrhoea was a frequently reported adverse event (≤14.2 percent), but it was mostly mild and transient. Importantly, the reported slight increase in mean serum ferritin was likely driven by simultaneous iron supplementation rather than SO. [Clin Kidney J 2021;14:1770-1779]
“The clinical benefit of SO extends beyond lowering phosphate levels,” said Zuo. “It has been associated with reduced calcification propensity, which may lower the risk of soft tissue and vascular calcification. It is also associated with increases in albumin-to-phosphate ratios, suggesting improved nutritional status, since it allows patients to maintain [adequate] protein intake without compromising phosphate control.” [Clin Kidney J 2020;14:631-638; J Ren Nutr 2019;29:428-437]
