Lanthanum carbonate (Fosrenol®) efficacy and tolerability in the treatment of hyperphosphatemic patients with end-stage renal disease

Abstract

High serum phosphorus levels are a common problem in patients receiving long-term dialysis treatment. Lanthanum carbonate (Fosrenol) is a new non-aluminum, non-calcium phosphate binder developed for the treatment of hyperphosphatemia in patients with end-stage renal disease (ESRD). We report data from a recent trial, which, for the first time, assessed the efficacy and tolerability of lanthanum carbonate treatment, compared with placebo, in Chinese patients with ESRD. Following a one- to three-week washout phase and a four-week, open-label lanthanum carbonate dose-titration phase, male and female hemodialysis patients were randomized (1:1) to receive either lanthanum carbonate or placebo for four weeks. The primary efficacy parameter of the study was the control of serum phosphorus levels (< or =1.8 mmol/l [< or = 5.6 mg/dl]). Secondary endpoints included the profile of serum phosphorus during titration and parathyroid hormone, calcium, and calcium x phosphorus (Ca x P) product levels. The safety and tolerability of lanthanum carbonate were assessed by monitoring adverse events throughout the study. Mean serum phosphorus level at the end of washout was 2.5 +/- 0.5 mmol/l (7.7 +/- 1.5 mg/dl; n=73), and there was no evidence of a difference in levels between the treatment groups pre-randomization. At the end of the study, lanthanum carbonate-treated patients had significantly lower phosphorus levels (1.6 +/- 0.5 mmol/l [5.1 +/- 1.5 mg/dl]; n=30) than those receiving placebo (2.3 +/- 0.4 mmol/l [7.2 +/- 1.3 mg/dl]; n=31; p < 0.001). In addition, a significantly higher proportion of patients receiving lanthanum carbonate had controlled serum phosphorus levels (60%) compared with the placebo group (10%; p < 0.001). Ca x P product levels were also significantly lower in the lanthanum carbonate group at the end of randomized treatment (p < 0.001). Lanthanum carbonate was well tolerated; only one serious adverse event was reported, which was unrelated to treatment. Lanthanum carbonate was shown to be an effective and well-tolerated phosphate binder for the treatment of hyperphosphatemia in Chinese patients with ESRD. This finding supports the results of previous US and European studies, which have also shown that lanthanum carbonate treatment effectively controls serum phosphorus levels.