Efficacy, acceptability and tolerability of the new oral phosphate binder Lenziaren® in healthy cats fed a standard diet

Background: The efficacy, acceptability and tolerability of the new oral phosphate binder Lenziaren (R) (SBR759) were evaluated in a randomized parallel-group design study in 36 healthy cats (n = 6 per group). Five groups were fed once daily with a commercial diet containing 0.2% phosphorus ("standard diet") into which was mixed Lenziaren (R) at 0.25, 0.5, 1.0 or 2.0 g/day or no treatment (control group) daily for 30 days. A sixth group was fed a commercial diet containing lower amounts (0.12%) of phosphorus ("renal diet") and no treatment. Results: When compared to the control group, Lenziaren (R) produced significant dose-related reductions in urine phosphate concentrations, urine phosphate excretion and fractional urinary phosphate excretion. Significant effects versus the control group were observed at the 0.5, 1.0 and 2.0 g/day dosages. Lenziaren (R) was well tolerated and was associated with higher food consumption and serum iron concentrations versus the control. When compared to the control group, the renal diet was associated with significantly lower urine phosphate concentrations and loss of body weight. Lenziaren (R) had similar effects on urine phosphate concentrations compared to the renal diet, but was not associated with loss of body weight. Conclusions: Lenziaren (R) was effective as an oral phosphate binder in cats fed with a standard diet containing 0.2% phosphorus. The acceptability and tolerability were good. Dosages of 0.5-1.0 g/cat per day are recommended for clinical testing in cats fed with a standard diet.