Novel phosphate binder oxylanthanum carbonate effectively reduced serum and urine phosphorus concentrations in animal models

Abstract

Abstract Objectives Over 40% of dialysis patients have above-target phosphate. The efficacy and safety of oxylanthanum carbonate (OLC), a novel phosphate binder that forms the same insoluble phosphate complex as lanthanum carbonate, were assessed in two animal models. Methods Three groups of nephrectomized cats (n = 4 per group) received 0.0466 g OLC/kg body weight, 0.233 g OLC/kg body weight, or placebo. Six groups of rats (n = 6 per group) received placebo or 0.049, 0.099, 0.197, 0.394 or 0.788 g OLC/day. Endpoints included phosphate concentrations (urine, faecal and plasma) and serum lanthanum concentrations. All animals were observed for tolerance, injury and mortality. Key findings In cats, urine phosphorus concentrations decreased across treatment groups and faecal phosphorus excretion increased in higher dose groups compared to control and lower dose groups. A clear but non-significant decline in plasma phosphate was observed. In rats, urine phosphorus concentrations also decreased in all groups. The majority of serum lanthanum concentrations for rats in treatment groups were not significantly different from those in control groups. The study drug was well tolerated in both models. Conclusions OLC was effective for phosphate management and efficacy may be dose dependent. OLC was safe and well tolerated, indicating that it should be evaluated in the target population of patients with hyperphosphatemia.