Zerenex(TM) (Ferric Citrate) Long-Term Phase 3 Study Results Published in the Journal of the American Society of Nephrology

Data Demonstrate the Drug Candidate's Potential to Become the First Phosphate Binder to Increase Iron Stores While Reducing the Need for IV Iron and Erythropoiesis-Stimulating Agents in End-Stage Renal Disease Patients on Dialysis

NEW YORK, July 24, 2014 (GLOBE NEWSWIRE) -- Keryx Biopharmaceuticals, Inc. (Nasdaq:KERX) (the "Company") announced the publication of results from the long-term, randomized, active control Phase 3 study of Zerenex (ferric citrate), the Company's investigational oral ferric iron-based phosphate binder, for the treatment of hyperphosphatemia in patients with end-stage renal disease (ESRD) on dialysis. The PERFECTED study (PhosphatE binding and iRon delivery with FErric CiTrate in EsrD) was published online today in the Journal of the American Society of Nephrology (JASN).

This Phase 3 study was a multicenter, randomized, open-label trial in 441 ESRD patients on hemodialysis or peritoneal dialysis designed to determine the safety and efficacy of Zerenex as a treatment to reduce serum phosphorus as well as raise iron stores and reduce intravenous (IV) iron and erythropoietin-stimulating agents (ESA) usage.

Zerenex met the study's primary end-point demonstrating a highly statistically significant change in serum phosphorus versus placebo over the four-week Placebo Control Period. Using a sequential gatekeeping strategy for the key pre-defined secondary end-points, Zerenex also demonstrated statistically significant increases in serum ferritin and transferrin saturation (TSAT), and significant reductions in the use of IV iron and ESAs, versus an active control of Renvela^® (sevelamer carbonate) and/or Phoslo^® (calcium acetate) over the 52-week Active Control Period of the study. In addition, mean hemoglobin levels were higher in subjects treated with Zerenex as compared to subjects treated with active control.

"Zerenex effectively reduces serum phosphorus levels within the KDOQI range (3.5 mg/dL to 5.5 mg/dL) while having the additional patient benefits of increasing iron stores and decreasing the need for IV iron and ESAs, while maintaining hemoglobin levels," said Julia Lewis, MD, lead investigator, nephrologist and Professor of Medicine at Vanderbilt University Medical Center. "If approved, the combined benefits of Zerenex would be of value for patients, health care professionals and the healthcare system."