Effect of chitosan chewing gum on reducing serum phosphorus in hemodialysis patients: a multi-center, randomized, double-blind, placebo-controlled trial

Abstract

Background: HS219 (40 mg chitosan-loaded chewing gum) is designed to bind salivary phosphorus as an add-on to available phosphorus binders. We performed a randomized, placebo-controlled, double-blind study to evaluate the efficacy and safety of HS219 in hemodialysis (HD) patients with hyperphosphatemia as an add-on to phosphorus binders.

Methods: Sixty-eight HD patients who were maintained on calcium carbonate (n=33) or sevelamer hydrochloride (n=35) were enrolled. The primary end point was a change in serum phosphorus levels. Secondary end points included changes in levels of salivary phosphorus, serum calcium, parathyroid hormone (PTH), and intact fibroblast growth factor (iFGF) 23.

Results: Sixty-three patients chewed either HS219 (n=35) or placebo (n=28) for 30 min, three times a day, for 3 weeks. HS219 was well tolerated and safe. However, HS219 was not superior to placebo with additional reduction of serum phosphorus with respect to phosphorus binders at the end of the chewing period. There were no significant effects of HS219 on reduction of salivary phosphorus, serum calcium, iPTH, or iFGF23 levels.

Conclusions: The chitosan-loaded chewing gum HS219 does not affect serum and salivary phosphorus levels in Japanese HD patients with hyperphosphatemia. Our findings do not support previous findings that 20 mg of chitosan-loaded chewing gum reduces serum and salivary phosphorus levels.

Trial registration: [corrected] ClinicalTrials.gov NCT01039428, 24 December, 2009.

Figure 1

Flow chart of patients enrolled in the study. The following populations were defined. (i) The full analysis set (FAS) included a subset of patients who subsequently received chewing gum and had any of the variables for efficacy measured. (ii) The safety analysis set (SAF) included a subset of patients who received one or more doses of the chewing gum.