Relypsa, Inc., announced the initiation of patient enrolment in a phase 2, open-label titration clinical study of the company’s lead drug candidate, RLY5016, in heart failure patients with chronic kidney disease. RLY5016 is a novel non-absorbed oral potassium binder intended to prevent and treat hyperkalemia, a serious condition characterized by elevated serum potassium levels.

The open-label study of heart failure patients with chronic kidney disease is intended to explore dosing of RLY5016 and an aldosterone antagonist with the aim of maintaining serum potassium levels in the normal range. Data from this study will be used in the design of late-stage clinical trials. The current phase 2 open-label study follows the successful completion of Relypsa’s phase 2 clinical trial, PEARL-HF, which evaluated RLY5016 versus placebo in the prevention of hyperkalemia in heart failure patients. PEARL-HF results will be presented at the European Society of Cardiology (ESC) Congress 2010 being held August 28 – September 1, 2010 in Stockholm, Sweden.

“While cardiovascular agents, such as aldosterone antagonists, are proven effective in heart failure and chronic kidney disease, their use is limited by the risk and incidence of uncontrolled elevated potassium levels that can lead to serious consequences. Thus, the threat of hyperkalemia creates a treatment dilemma for physicians taking care of patients with heart failure and chronic kidney disease,” said Gerrit Klaerner, Ph.D., Relypsa’s president.

“In the light of the recent EMPHASIS-HF data, the third outcome trial for aldosterone antagonists that demonstrated a significant mortality reduction in heart failure patients, RLY5016 holds great promise in managing hyperkalemia and enabling the use of these life-saving drugs. We believe that RLY5016 may become an essential tool for cardiologists and nephrologists based on the promising data achieved in clinical studies conducted to date,” noted I-Zu Huang, M.D., Relypsa’s vice president of clinical development.

The open-label trial will enrol approximately 60 heart failure patients with chronic kidney disease currently under treatment with one or more heart failure drugs, including angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARB) or beta blockers. All patients will receive oral RLY5016 and spironolactone, a commonly used aldosterone antagonist. Over the course of the eight-week study, RLY5016 or spironolactone doses may be adjusted (titrated) according to a dosing algorithm with the intent of maintaining each patient’s serum potassium levels within a normal target range.

RLY5016 is a high capacity non-absorbed oral potassium binder being developed for the management of hyperkalemia in heart failure and chronic kidney disease patients. In preclinical and clinical studies RLY5016 has been shown to reduce serum potassium levels and has been consistently well-tolerated in multiple clinical trials among healthy volunteers and patients.

Relypsa has successfully completed several clinical trials of RLY5016, including the PEARL-HF phase 2 clinical trial, a multi-centre, randomized, placebo-controlled study designed to assess the efficacy, safety and tolerability of RLY5016 for the prevention of hyperkalemia in heart failure patients.

Relypsa, Inc. is a privately-held, development-stage biopharmaceutical company leading the discovery and development of novel non-absorbed polymeric drugs for important applications in cardiovascular and renal diseases.