Relypsa Announces Topline Results From Patiromer Phase 1 Onset-of-Action Study

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REDWOOD CITY, Calif., May 12, 2014 (GLOBE NEWSWIRE) -- Relypsa, Inc. (Nasdaq:RLYP), a biopharmaceutical company, today announced topline results from its Phase 1 onset-of-action study of patiromer, the final clinical trial planned to support a New Drug Application (NDA), which the company expects to submit to the U.S. Food and Drug Administration (FDA) in the third quarter of 2014. The study reached its primary endpoint in which an early onset of potassium lowering action was observed. Following the first dose of patiromer, reductions in mean serum potassium were observed at all examined time points, with statistical significance first demonstrated at the second measurement (7 hours post drug administration). Over the 48-hour treatment period, during which patiromer was dosed twice daily, the potassium lowering effect was sustained with a steady decline in mean serum potassium, with no loss of effect or rebound in mean potassium levels during night-time periods.

"We are excited to share these topline results which support the rapid onset-of-action of patiromer and round out the drug's clinical story as a complement to our additional long-term studies, including chronic 12-month treatment data," said Lance Berman, M.D., chief medical officer of Relypsa. "These data are particularly encouraging as they were generated in a patient population at high risk for mortality due to moderate to severe hyperkalemia, a main focus of physicians as they address disease management and the use of RAAS inhibitor therapy."

The open-label, single-arm trial was designed to evaluate the time-to-onset of the potassium-lowering action in chronic kidney disease (CKD) patients with hyperkalemia who were taking at least one renin-angiotensin-aldosterone system (RAAS) inhibitor. Following a 3-day restricted potassium diet run-in period to control and stabilize dietary intake of potassium, the study enrolled 25 patients with baseline serum potassium levels of 5.5 to less than 6.5 mEq/L. Patients were treated twice daily with 8.4 g of patiromer per dose and observed over a 48-hour period, followed by a 7-day post-treatment safety follow-up period.

Results showed that a statistically significant reduction from baseline in serum potassium levels was demonstrated at 7 hours after the start of treatment and was maintained at all subsequent evaluations out to 48 hours (approximately 14 hours after the last dose) (p<0.001 at 48 hours). During the trial, mean serum potassium was reduced from 5.93 mEq/L at baseline to a maximum mean reduction of 0.83 mEq/L, which achieved the study's primary pharmacodynamic endpoint. There were no reports of serious adverse events or discontinuations due to adverse events.

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 chronic kidney disease, 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 renin-angiotensin-aldosterone-system (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, non-metal oral potassium binder being developed for the treatment of hyperkalemia. The compound has been evaluated in CKD patients with hyperkalemia, including a two part Phase 3 study, a 12-month Phase 2 trial and a 48-hour short-term Phase 1 onset-of-action study. In all of those studies, patiromer met its efficacy endpoints and the treatment was well tolerated. The pivotal clinical study for patiromer is complete and was conducted under a Special Protocol Assessment with the FDA.

About Relypsa, Inc.

Relypsa, Inc. is a 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

Forward Looking Statements

To the extent that statements contained in this press release are not descriptions of historical facts regarding Relypsa, they are forward-looking statements reflecting the current beliefs and expectations of management made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, including statements regarding the timing of our NDA submission and the potential clinical significance of the topline results from our Phase 1 onset-of-action study. Such forward-looking statements involve substantial risks and uncertainties that relate to future events and the actual results could differ significantly from those expressed or implied by the forward-looking statements. Such risks and uncertainties include, among others, the uncertainties inherent in the clinical drug development process, including the regulatory approval process, the timing of the company's regulatory filings, the company's substantial dependence on patiromer, the company's commercialization plans and efforts and other matters that could affect the availability or commercial potential of patiromer. Relypsa undertakes no obligation to update or revise any forward-looking statements. For a further description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to the business of the company in general, see Relypsa's current and future reports filed with the U.S. Securities and Exchange Commission, including its Quarterly Report on Form 10-Q for the quarter ended March 31, 2014.

CONTACT: Sylvia Wheeler V.P. Investor Relations and Corporate Affairs 650-421-9504

Source:Relypsa, Inc.