Author Interviews, Kidney Disease, NEJM / 19.01.2015
New Drug For Hyperkalemia Selectively Traps Potassium
MedicalResearch.com Interview with:
David K. Packham, M.B., B.S., M.D
Royal Melbourne Hospital
Melbourne Renal Research Group VIC 3073, Australia,
Medical Research: What is the background for this study? What are the main findings?
Dr. Packham: ZS-9 represents a new mechanism of action for addressing hyperkalemia. Unlike traditional nonspecific organic polymer cationexchangers, ZS-9 is a non-absorbed, inorganic crystalline potassium-selective cation exchanger that traps excess potassium in the gastrointestinal tract. It has been evaluated in three prospective, randomized, double-blind, placebo-controlled studies with over 1100 patients to date, representing the largest ever clinical development program for hyperkalemia.
ZS-003 was the first of two pivotal Phase 3 studies that evaluated the safety and efficacy of ZS-9 in patients with hyperkalemia. In ZS-003, treatment of patients with an oral suspension of ZS-9 (2.5, 5, or 10 grams, three times a day) resulted in statistically significant and clinically meaningful reductions in serum potassium, compared with placebo, during the “acute phase” (first 48 hours), with 99 percent of patients achieving normal potassium levels with the highest 10 gram dose. During the next 12 days of the trial (the “maintenance phase”), ZS-9 (5 or 10 grams) given once daily could maintain the corrected potassium levels achieved during the acute phase. In contrast, patients who were randomized back to placebo after achieving normal potassium reverted back to hyperkalemia. The tolerability profile has been favorable, with adverse event rates from ZS-9 similar to that of placebo. (more…)