SLC20A1

The goal of this clinical trial is to learn if AP306 could work in the patients receiving maintenance hemodialysis with elevated blood phosphate. The main questions it aims to answer are:
* Does AP306 lower blood phosphate levels when the participants take a fixed dose of AP306?
* What medical problems do the participants have when taking AP306?
The researchers will compare AP306 to a placebo (a look-alike substance that contains no drug) to see if AP306 works to treat hyperphosphatemia.
The participants will:
* Stop all using blood phosphate-lowering drugs, and
* Take AP306 or a placebo three times a day for 12 weeks.
If the participant has a blood phosphate level above a certain level, they will receive additional treatment to lower the blood phosphate level.

本研究的主要疗效目的是根据以下终点评价 AP-306 的有效性：在接受维持性血液透析的高磷血症患者中探索 AP-306 降低血清磷水平的能力；安全性目的是评价AP-306的总体安全性和耐受性。

The goal of this clinical trial is to learn about the following questions in the patients receiving maintenance hemodialysis with elevated blood phosphorus:
How much effect AP-306 has assessed by blood phosphorus lowering;
How safe and tolerable AP-306 is.
Participants will receive either following treatments:
AP-306, and
Sevelamer carbonate.