As an added boost to previously announced positive results that identified ZS Pharma‘s investigational drug ZS-9 (sodium zirconium cyclosilicate) as safe and effective for managing hyperkalemia in patients with the chronic condition, ZS-9 appears to prevent the recurrence of hyperkalemia in patients with heart failure. A secondary analysis of data generated by the phase 3 trial ZS003 showed that taking ZS-9 once a day prevented hyperkalemia from recurring in heart failure patients who were also taking renin angiotensin aldosterone inhibitor (RAASi) therapy.
“The findings that once-daily doses of ZS-9 maintained normal potassium levels in heart failure patients with recent hyperkalemia, despite use of RASSi, are encouraging,” stated Mohamed A. El-Shahway, MD, MPH, MHA, FASN, who was a clinical investigator on ZS003, in a news release from the company. “These results suggest that ZS-9 may enable physicians to optimize the dose of RASSi therapy in these patients by normalizing their potassium levels.”
Heart failure patients are at a risk for experiencing hyperkalemia due to medications that are designed to treat heart disease. “Clinical Treatment Guidelines strongly recommend RAAS inhibitors for patients with heart failure,” explained Dr. El-Shahawy. “Yet, studies report that nearly half of these patients receive suboptimal RAASi therapy, often because these patients have hyperkalemia or develop it with the use of RAASi.” It seems as though ZS-9 may be implicated in these patients to prevent the onset of hyperkalemia.
Since this was a secondary analysis, no new patient data was collected, but data was analyzed from a different perspective. Researchers investigated whether ZS-9 prevented the recurrence of hyperkalemia relative to placebo in the subset of patients with heart failure and RAASi therapy. In total, 147 normokalemic heart failure patients on RAASi therapy who had been randomized to the once-daily ZS-9 or placebo groups were considered. Data showed a lower level of potassium in patients using either 5 g or 10 g of ZS-9 once a day and a potassium level for placebo patients that qualified as hyperkalemia.
Studies involving ZS-9 are ongoing. In July, ZS Pharma announced that the phase 3 trial ZS004 completed enrollment and that results are expected early in 2015. The trial is now known as “Hyperkalemia Randomized Intervention Multi-Dose ZS-9 Maintenance Clinical Trial” (HARMONIZE) and is expected to further support the safe and efficacious use of ZS-9 to treat patients with hyperkalemia.