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

Tadao Akizawa1*, Yoshinari Tsuruta2, Yoichi Okada3, Yoshihiro Miyauchi4, Akio Suda5, Hiroshi Kasahara6, Nobuhiro Sasaki7, Yoshitaka Maeda8, Takako Suzuki9, Noriaki Matsui10, Jun Niwayama11, Toshiaki Suzuki12, Hideaki Hara13, Yasushi Asano7, Sadao Komemushi14 and Masafumi Fukagawa15

Author Affiliations

1 Showa University School of Medicine, Tokyo, Japan

2 Meiyo Clinic, Toyohashi, Japan

3 Maruko General Hospital, Ueda, Matsumoto, Japan

4 Asahi General Hospital, Asahi, Chiba, Japan

5 Suda Clinic, Tokyo, Japan

6 Japanese Red Cross Suwa Hospital, Suwa, Nagano, Japan

7 Japanese Red Cross Koga Hospital, Koga, Ibaragi, Japan

8 JA Toride Medical Center, Toride, Ibaragi, Japan

9 Komagome Kyouritsu Clinic, Tokyo, Japan

10 Tsuchiura Kyodo General Hospital, Tsuchiura, Ibaragi, Japan

11 Sumiyoshi Clinic Hospital, Mito, Ibaragi, Japan

12 Asagaya Suzuki Clinic, Tokyo, Japan

13 Gifu Pharmaceutical University, Gifu, Japan

14 Osaka City University Faculty of Engineering, Osaka, Japan

15 Tokai University School of Medicine, Isehara, Japan

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BMC Nephrology 2014, 15:98  doi:10.1186/1471-2369-15-98

Published: 25 June 2014



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.


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.


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.


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.

Trail registration NCT01039428, 24 December, 2009.

Chewing gum; Chitosan; Clinical trial; Hemodialysis; Hyperphosphatemia; Phosphorus binders