Randomized controlled trial of bixalomer versus sevelamer hydrochloride in hemodialysis patients with hyperphosphatemia

Abstract

Hyperphosphatemia is a prognostic factor for morbidity and mortality in chronic kidney disease. Bixalomer is a nonabsorbable polymer that decreases serum phosphate levels by binding phosphate in the gastrointestinal tract. This study compared the efficacy and safety of bixalomer versus sevelamer hydrochloride for controlling hyperphosphatemia in hemodialysis patients. This was a multicenter, randomized open-label, non-inferiority study. The primary endpoint was serum phosphate on completion of treatment. Administration of bixalomer was started at 1.5 g/day and adjusted to a maximum of 7.5 g/day depending on the serum phosphate level. Sevelamer hydrochloride was started at 3.0 or 6.0 g/day and adjusted to a maximum of 9.0 g/day. Treatment was continued for 12 weeks. Fifty-five patients were randomized to each treatment group. After 12 weeks, the baseline adjusted mean serum phosphate level was 5.87 mg/dL in the bixalomer group and 5.55 mg/dL in the sevelamer group, with a difference of 0.31 mg/dL and 95% confidence interval (CI) of [-0.13 to 0.76]. The upper limit of the 95%CI for the difference of the mean serum phosphate level between the two groups was <1.0 mg/dL, which was the non-inferiority margin in this study. Thus, non-inferiority of bixalomer to sevelamer was confirmed. The incidence of adverse events was lower in the bixalomer group, and bixalomer did not promote acidosis. Bixalomer achieved a similar reduction of serum phosphate to sevelamer, while causing fewer adverse reactions. Consequently, the usefulness of bixalomer for treating hyperphosphatemia was confirmed.

Keywords: Bixalomer; Hemodialysis; Hyperphosphatemia; Kidney disease; Randomized controlled trial; Treatment efficacy.