Relypsa Reports Positive Topline Results for its 52-Week Phase 2b Trial of Patiromer
Redwood City, CA, October 17, 2013 – Relypsa, Inc., a clinical-stage biopharmaceutical company, today announced that its Phase 2b trial studying the safety and efficacy of patiromer as a treatment for hyperkalemia has met the primary efficacy endpoint for the trial. Additionally, treatment with patiromer maintained mean serum potassium within the normal range for up to one year, supporting persistence of the potassium lowering effect of patiromer over time. These clinically meaningful results provide supportive evidence for the efficacy, safety and tolerability of patiromer as a treatment for hyperkalemia when dosed twice daily over the long-term.
The Phase 2b trial was an open-label, randomized, dose ranging trial to determine the optimal starting dose(s) and the efficacy and safety of patiromer when used over the long-term to treat hyperkalemia. Three hundred six (306) patients were randomized into the trial. In the 8-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 5.1 to 5.5 mEq/L) or Stratum 2 (baseline serum potassium 5.6 to less than 6.0 mEq/L), were randomized to one of three different starting doses of patiromer depending on the stratum, and, if needed based on their serum potassium levels, their patiromer doses were individually titrated. All patients could continue receiving patiromer in the 44-week Long-term Maintenance Period for a total of one year of treatment.
Treatment Initiation Period (first eight weeks)
• The primary endpoint was met with a statistically significant mean change in serum potassium from baseline to week 4 or time of first dose titration, irrespective of the patients’ serum potassium at baseline:
– For patients in Stratum 1, the change from baseline in serum potassium was –0.47 mEq/L (95% CI -0.55, -0.40; p < 0.0001).
– For patients in Stratum 2, the change from baseline in serum potassium was –0.92 mEq/L (95% CI -1.07, -0.78; p < 0.0001).
• During the Treatment Initiation Period, statistically significant reductions from baseline in serum potassium were observed in each stratum at each study visit, and as early as two days after initiating treatment with patiromer.
Long-Term Maintenance Period (week 8 through week 52)
• Throughout the 44-week Long-Term Maintenance Period (following the 8-week Treatment Initiation Period), the mean serum potassium in both Stratum 1 and Stratum 2 remained in the target serum potassium range (3.8 to 5.0 mEq/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%).
Patiromer was well tolerated in this trial when dosed twice daily for up to one year.
• The most common adverse events were mild to moderate gastrointestinal symptoms, with constipation and diarrhea reported in 5-10% of patients. The incidence of gastrointestinal AEs did not increase over time with chronic dosing.
• Mild to moderate hypomagnesemia was reported in less than 10% of patients. There were no reports of severe hypomagnesemia.
• Other common adverse events reported in less than 10% of patients included hypertension and worsening of the underlying chronic renal failure.
• Serious adverse events were reported in 15% of patients, and all such events were assessed by the trial investigators and Relypsa as not related to patiromer.
According to President and Chief Executive Officer John Orwin, “These positive top line results confirm the results from the interim analysis of the Phase 2b Treatment Initiation Period presented at the American Society of Nephrology Kidney Week last year. In addition, these Phase 2b data plus our recently announced positive results from our pivotal Phase 3 trial position us to proceed to an NDA submission and underscore patiromer’s profile as a well-tolerated and effective potassium control agent that can be used daily over the long-term and provide value to both physicians and their patients with CKD and heart failure.”
About Hyperkalemia and Patiromer
Hyperkalemia, a life-threatening condition defined as abnormally elevated levels of potassium in the blood, is frequently prevalent in patients who suffer from renal impairment, hypertension, diabetes and/or heart failure. Hyperkalemia can lead to cardiac arrhythmia and sudden death. Patients with chronic kidney disease or heart failure are at particular risk for developing hyperkalemia, especially those treated with RAAS inhibitors such as ARBs (Angiotensin Receptor Blockers), AAs (Aldosterone Antagonists), and ACE (Angiotensin-Converting-Enzyme) Inhibitors. Although RAAS inhibition has been shown to protect kidney and cardiac function, many patients who could benefit from RAAS inhibitors are untreated or undertreated due to the undesirable side effect of increasing serum potassium.
Patiromer (RLY5016 for Oral Suspension) is a high capacity non-absorbed oral potassium binder being developed for the treatment of hyperkalemia. Relypsa has completed several clinical trials of patiromer that have demonstrated the preliminary efficacy, safety and tolerability of patiromer in patients with hyperkalemia.
About Relypsa, Inc.
Relypsa, Inc. is a privately held clinical-stage biopharmaceutical company focused on the development and commercialization of non-absorbed polymeric drugs to treat disorders in the areas of renal, cardiovascular and metabolic diseases. The company’s two-part pivotal Phase 3 trial of its lead product candidate, patiromer, for the treatment of hyperkalemia, a life-threatening condition defined as abnormally elevated levels of potassium in the blood, has been completed and the primary and secondary endpoints were met. Relypsa has global royalty-free commercialization rights to patiromer, which has intellectual property protection in the U.S. until at least 2030. More information is available at
Relypsa, Inc.
Shari Annes, IR and Corporate Communications
IR, 650-888-0902