November 25, 2013

Relypsa released results of a phase IIb trial of patiromer as a treatment for hyperkalemia. The open-label, randomized, dose-ranging trial enrolled 306 patients. In the eight-week Treatment Initiation Period, patients were eligible for enrollment if they were hyperkalemic, had chronic kidney disease and type 2 diabetes mellitus and were taking a renin angiotensin aldosterone system (RAAS) inhibitor medication prior to screening. Patients were assigned to Stratum 1 (baseline serum potassium 5.1mEq/L to 5.5mEq/L) or Stratum 2 (baseline serum potassium 5.6mEq/L to less than 6mEq/L), and were randomized to one of three different starting doses of patiromer depending on the stratum. All patients could continue receiving patiromer in the 44-week Long-term Maintenance Period for a total of one year of treatment. For patients in Stratum 1, the change from baseline in serum potassium was –0.47mEq/L (95% CI -0.55, -0.40; p. For patients in Stratum 2, the change from baseline in serum potassium was –0.92mEq/L (95% CI -1.07, -0.78; p. Throughout the Long-Term Maintenance Period (following the eight-week Treatment Initiation Period), the mean serum potassium in both Stratum 1 and Stratum 2 remained in the target serum potassium range (3.8mEq/L to 5mEq/L). At week 52, the proportion of patients with a serum potassium in the target range was 85.5% in Stratum 1 (95% CI 78.7%, 90.8%) and 89.8% in Stratum 2 (95% CI 77.8%, 96.6%).