Reducing high phosphate levels in patients with chronic renal failure undergoing dialysis: a 4-week, dose-finding, open-label study with lanthanum carbonate.

BACKGROUND The majority of patients with end-stage renal disease on dialysis are hyperphosphataemic. Lanthanum carbonate has been shown to be a highly effective phosphate binder in pre-clinical studies. A 4-week, open-label, dose-titration trial was conducted to assess the ability of lanthanum carbonate to control phosphate levels in patients with chronic renal failure. METHODS This preliminary study was of 6 weeks duration: 2 weeks of washout followed by 4 weeks of dose titration. Patients (n = 59) were titrated on the basis of weekly serum phosphate levels from a daily dose of 375 mg lanthanum carbonate to a maximum dose of 2250 mg. Patients were maintained on the dose that controlled serum phosphate to between 1.30 and 1.80 mmol/l (4.03-5.58 mg/dl). Serum phosphate levels represented the main efficacy assessment. Safety was also evaluated. RESULTS Most patients were successfully titrated to 1500 and 2250 mg lanthanum/day (mean dose at end of titration: 1278 mg). At completion of the study 70% of patients achieved a serum phosphate of <or=1.80 mmol/l. The use of lanthanum carbonate in patients undergoing continuous ambulatory peritoneal dialysis or haemodialysis was generally well tolerated. CONCLUSIONS Lanthanum carbonate, a new non-aluminium, non-calcium phosphate binder, effectively reduces serum phosphate levels. Results of longer-term efficacy and safety studies are awaited with interest.