Relypsa Reports Positive Top-Line Results for the First Part of Its Two-Part Pivotal Phase 3 Trial of Patiromer
Redwood City, CA, September 10, 2013 – Relypsa, Inc., a clinical-stage biopharmaceutical company, today announced positive top-line results on both the primary and secondary efficacy endpoints of Part A, the patiromer treatment part, of its two-part pivotal Phase 3 clinical trial evaluating patiromer for the treatment of hyperkalemia. The primary endpoint for Part A was the change in serum potassium from baseline to week 4, which showed a statistically significant reduction of 1.01 mEq/L (p < 0.001). For the secondary endpoint for Part A, 76% of subjects had a serum potassium in the target range of 3.8 to < 5.1 mEq/L at week 4, which was statistically significant (95% confidence interval: 70%, 81%). There were two serious adverse events (SAEs) reported in Part A of the study, and neither SAE was assessed as related to patiromer. The company expects to report primary endpoint results from Part B of this trial in the fourth quarter of 2013.
The two-part Phase 3 clinical trial was conducted under an agreed upon special protocol assessment (SPA) with the U.S. Food and Drug Administration (FDA). Part A, in which all participants received patiromer, was a single-blind, single-arm trial in 243 subjects with hyperkalemia and chronic kidney disease (CKD) who were also being treated with renin angiotensin aldosterone system (RAAS) inhibitor medications. The FDA-agreed upon primary endpoint of Part A under the SPA was the change in serum potassium from Part A baseline to Part A week 4. The secondary endpoint was the proportion of subjects with a serum potassium in the target range of 3.8 to < 5.1 mEq/L at Part A Week 4. The Company expects to provide additional details on the results of the study at a major medical meeting.
Part B, the placebo controlled randomized withdrawal part of the study, was designed to provide additional evidence of the efficacy of patiromer in treating hyperkalemia and to assess the need for chronic dosing. Subjects from Part A whose baseline serum potassium level was greater than or equal to 5.5 mEq/L at enrollment and whose serum potassium level was controlled at week 4 were eligible for Part B. These subjects were then randomized into two groups; one to continue on patiromer, and a second to receive placebo for an additional eight weeks. The primary endpoint for Part B is the between group difference in the change in serum potassium from Part B baseline to week 4 of Part B. These results are expected in the fourth quarter of 2013.
According to Chief Executive Officer John Orwin, “The Part A results are both statistically significant and clinically meaningful. We observed a large and robust reduction in serum potassium. In addition, there was a very high response rate with 76% of subjects reaching the target serum potassium range. Given the limited treatment options for patients with hyperkalemia, in particular those with chronic kidney disease or heart failure who are taking RAAS inhibitor medications, these data add to our strong foundation of clinical findings and point to patiromer as a well-tolerated and effective potassium control agent. We believe that the data further underscore the opportunity ahead for Relypsa, and we are eager to move forward on a path to seek regulatory approval of and commercialize patiromer.”
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 Special Protocol Assessments
A Special Protocol Assessment is a written agreement between a sponsor and the FDA that the design and planned analysis of a clinical trial can adequately address objectives in support of a marketing application. Final determinations for marketing approval are made after a complete review of a marketing application. Approval is based on the entire data in the application. For further information regarding the SPA process, please visit the FDA website,
About Relypsa, Inc.
Relypsa, Inc. is a privately held 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. Enrollment of 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. Relypsa has global royalty-free commercialization rights to patiromer and 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 “at”, 650-888-0902