US-based biopharmaceutical firm ZS Pharma has reported positive top-line results from its second Phase III clinical trial of ZS-9 (sodium zirconium cyclosilicate), a new investigational treatment for hyperkalemia.
Results from the Phase III trial HARMONIZE (ZS004) showed that all three doses 5g, 10g and 15g of once daily ZS-9 met the primary endpoint, showing that ZS-9 prevented recurrence of hyperkalemia when compared with placebo over a 28-day treatment period.
The global, prospective, randomised, double-blind, placebo-controlled trial enrolled 258 patients with hyperkalemia with no upper limit on serum potassium (K+) at entry.
According to the company, safety, tolerability and adverse events are generally consistent with previous ZS-9 clinical trials.
ZS Pharma chief executive officer Robert Alexander said: "With the completion of the HARMONIZE trial, we remain on track to submit NDA and MAA filings for ZS-9 in the first half of 2015."
The trial included patients with chronic kidney disease (CKD), heart failure (HF), diabetes and those on renin angiotensin aldosterone system (RAAS) inhibitor therapy.
In the open-label induction phase of the trial, patients were given 10g of ZS-9 three times daily for 48 hours and were monitored to establish the speed and magnitude of serum potassium reduction.
The ZS-9 clinical programme is designed to investigate the treatment of acute and chronic hyperkalemia, regardless of underlying cause.
The company has completed ZS003, a 753-patient Phase III trial, which showed that ZS-9 rapidly reduced serum potassium in hyperkalemic patients to normal levels within the 48-hour Acute Phase and then controlled potassium in the normal range throughout the 12-day Extended Treatment Phase.
Together with HARMONIZE, the company is also carrying out ZS004E, an extension trial that will generate longer-term open-label safety and tolerability data in patients who participated in HARMONIZE.
ZS005, an additional long-term safety study is also being conducted to evaluate the ability of ZS- 9 to restore and maintain normal serum potassium levels in patients with hyperkalemia over at least one-year of dosing.