Keryx commences Zerenex Phase 3 study for hyperphosphatemia in patients with ESRD on dialysis

Keryx Biopharmaceuticals, Inc. (Nasdaq: KERX) announced today the initiation of the long-term Phase 3 study of Zerenex™ (ferric citrate), the Company's iron-based phosphate binder for the treatment of elevated serum phosphorous levels, or hyperphosphatemia, in patients with end-stage renal disease (ESRD) on dialysis.  The initiation of this study marks the commencement of the final component of the Company's Phase 3 registration program for Zerenex, which is being conducted in accordance with a Special Protocol Assessment (SPA) agreement with the FDA.  Pursuant to the SPA agreement, the Zerenex Phase 3 registration program consists of a short-term efficacy study, which was initiated in May 2010 and is expected to be completed in the fourth quarter of 2010, and the 58-week long-term safety and efficacy study initiated today.

The long-term study initiated today is a multicenter, randomized, open-label, safety and efficacy clinical trial with a planned enrollment of approximately 300 ESRD patients on hemodialysis or peritoneal dialysis.  The study will consist of a 2-week washout period followed by a 52-week safety assessment in which patients will be randomized 2:1 to receive either Zerenex or an active control.  The 52-week safety assessment period will be followed by a 4-week efficacy assessment in which only patients randomized to treatment with Zerenex during the safety assessment period will be randomized in a 1:1 ratio to either continue treatment with Zerenex or switch to placebo for a 4-week efficacy assessment period.  Approximately 45 sites in the U.S. and select ex-U.S. sites will participate in the study.  Patient enrollment is expected to take approximately 6 to 9 months.  

Dr. Julia Lewis, Professor of Medicine, Department of Nephrology, Vanderbilt University School of Medicine, and member of the Executive Committee of the Collaborative Study Group, is the Study Chair of the Zerenex Phase 3 registration program.  Dr. Samuel S. Blumenthal, Professor of Medicine at Medical College of Wisconsin, is the study's Co-Principal Investigator.

Dr. Lewis commented, "We are excited to be leading this long-term safety and efficacy study of Zerenex and are looking forward to the pending completion of the short-term study. While there are treatment options available to patients with hyperphosphatemia, there are safety and compliance concerns associated with the currently marketed therapies.  The Phase 3 registration program is designed to confirm prior clinical data which suggests that Zerenex is potentially an attractive, differentiated treatment option for ESRD patients with hyperphosphatemia."

Ron Bentsur, Chief Executive Officer of Keryx, commented, "The initiation of the Phase 3 long-term study is an important milestone for the Company and brings us one step closer to potentially providing patients living with hyperphosphatemia with a viable alternative to the marketed phosphate binders. We also look forward to the completion of the Phase 3 short-term efficacy study by year end."

Keryx Biopharmaceuticals retains a worldwide exclusive license (except for the Asian Pacific Region) to Zerenex (ferric citrate) from Panion & BF Biotech, Inc.  The Company has sublicensed the development of ferric citrate in Japan to Japan Tobacco Inc. and Torii Pharmaceutical Co., Ltd.

SOURCE Keryx Biopharmaceuticals, Inc.