ZS Pharma, a specialty pharmaceutical company developing novel treatments for kidney, cardiovascular and liver disorders, today announced that it has begun enrolling patients in ZS004, its second Phase 3 clinical trial of ZS-9, a novel investigational treatment for hyperkalemia. This randomized, double-blind, placebo-controlled study is designed to confirm, over a longer treatment period, the positive results previously reported for ZS003, a Phase 3 trial in which a once-daily dose of ZS-9 (5g or 10g) maintained potassium levels within the normal range with safety and tolerability similar to placebo.
ZS004, a global multicenter, multi-dose, prospective clinical trial, is enrolling patients with hyperkalemia (potassium levels >5 mEq/L), including patients with chronic kidney disease (CKD), heart failure, diabetes, and those on renin angiotensin aldosterone system (RAAS) inhibitor therapy. In the open-label induction phase of the trial, approximately 275 patients with hyperkalemia will receive 10g of ZS-9 administered three times daily for 48 hours. Patients who achieve normokalemia (potassium levels between 3.5 and 5 mEq/L) are eligible to be randomized in a double-blind fashion to one of three doses of ZS-9 (5g, 10g or 15g) or placebo administered once-daily for 28 days. The primary efficacy endpoint of the ZS004 trial is the mean serum potassium level of each ZS-9 treatment group compared with that of placebo.
In conjunction with ZS004, ZS Pharma will also be conducting ZS004E, an extension study that will generate longer-term open-label safety, tolerability and efficacy data in patients who participated in ZS004. In ZS004E, patients will receive up to an additional 60 days of treatment, resulting in a combined potential of 90 days of treatment with ZS-9 over the course of ZS004 and ZS004E.