ZS Pharma

Committed to Advancing Patient Care


ZS-9 is an insoluble, non-absorbed zirconium silicate with a clearly defined three dimensional crystalline lattice structure that was designed and engineered to preferentially trap potassium ions. SPS (e.g., Kayexalate), the current standard of care for hyperkalemia in the United States, is a nonselective polymer resin. In contrast to nonselective polymer resins, the potassium selectivity of ZS-9 enables high in-vitro binding capacity for potassium ions even in the presence of other ions. Head-to-head in-vitro experiments demonstrate that ZS-9 has roughly ten times the potassium binding capacity of SPS. In our clinical studies, this selectivity has resulted in the following important differentiating characteristics for ZS-9 that we believe support its potential use to treat acute and chronic hyperkalemia:

• high efficacy, with 98% of patients from our completed clinical trials receiving a 10 gram dose returning to a normal level of potassium (between 3.5 and 5.0 mEq/L) in their blood, which is referred to as normokalemia, within 48 hours;

• rapid onset of action, with statistically significant reductions in potassium observed at one hour in patients receiving a 10 gram dose in our completed clinical trials;

• demonstrated ability in our studies to date to safely and effectively maintain normokalemia, with a low risk of reducing the level of potassium in the blood below 3.5 mEq/L, which is referred to as hypokalemia;

• potential suitability for chronic once daily administration;

• easily taken as a convenient oral suspension powder or dissolvable tablets;

• well-tolerated in our studies to date, with an incidence of adverse events similar to placebo;

• no effect on other electrolytes that are critical for normal physiological functioning, including sodium, calcium and magnesium; and

• stability at room temperature with a long shelf-life, which we expect will simplify distribution, physician sampling and storage for both physicians and patients.

Recent News

November 21, 2014

ZS Pharma Announces Publication of Results from Phase 3 Study of ZS-9 in Patients with Hyperkalemia in the New England Journal of Medicine

Download PDF

November 17, 2014

ZS Pharma Presents Positive Results from HARMONIZE (ZS004), a Second Phase 3 Clinical Trial of ZS-9 in Patients with Hyperkalemia, at the American Heart Association Scientific Meeting and Announces Simultaneous Publication of Results in JAMA

Download PDF

November 10, 2014

ZS Pharma Reports Third Quarter 2014 Financial Results and Provides ZS-9 Program Update

Download PDF

Keep up to date with the latest ZS Pharma News and Updates