NEW YORK, April 15 Keryx Biopharmaceuticals, Inc. (Nasdaq: KERX) today reported updated long-term efficacy and safety data on Zerenex(TM) (ferric citrate), the Company's iron-based phosphate binder for the treatment of hyperphosphatemia (elevated phosphate levels) from an open-label extension study in patients with end-stage renal disease (ESRD) who are on dialysis. This data was presented yesterday at the National Kidney Foundation (NKF) 2010 Spring Clinical Meeting taking place in Orlando, Florida in a poster entitled "Long-Term Use of Ferric Citrate in End-Stage Renal Disease Patients."
After the completion of a 28-day fixed dose Phase 2 clinical trial of ferric citrate in ESRD patients, 29 patients who had participated in this trial at the site in Taiwan were offered to continue onto an Open-Label Extension (OLE) trial for up to one year. There was approximately a two month period between the completion of the Phase 2 dose-ranging trial and enrollment into the OLE trial. During this time interval, no patient was exposed to ferric citrate as a phosphate binder. Patients were immediately switched back to ferric citrate from other phosphate binders and there was no washout period prior to starting ferric citrate treatment in the OLE trial. Of the 29 patients enrolled, 28 were exposed to ferric citrate. The patients were started on doses of ferric citrate of 2 to 6 g/day. The maximum allowed dose was 6 g/day. The average dose per patient throughout the study was approximately 4.5 g/day. The average duration of the patient's participation in the trial was 306 +/- 85 days. The primary objective of this OLE trial of ferric citrate was to assess the long-term efficacy and safety of ferric citrate as a phosphate binder in ESRD patients for up to one year. The secondary objective of this OLE trial was to assess for the potential for iron absorption.
The therapeutic goal of the study was to achieve and maintain a serum phosphorus level below 5.5 mg/dL. The mean levels of serum phosphorus (SP) and phosphorus x calcium product (PxC) for the evaluable patients at each time point over the treatment period were as follows:
Iron parameters were measured at baseline and then quarterly through month 9. On average, slight increases were observed over time, across all key parameters, as follows:
If a patient had a ferritin > 600 ng/mL and a TSAT > 50%, the use of IV iron was withheld until the patient's ferritin and TSAT were below the above levels during the treatment period. If a patient had a hematocrit (HCT) > 36%, the use of EPO was withheld until the HCT was < 36% during the treatment period.
There were 8 patients that had IV iron supplements withheld for approximately 3 to 6 months and there were 8 patients that had EPO withheld for approximately 1 to 10 months during the OLE trial. Out of the 16 patients in the two groups, three patients had both IV iron and EPO withheld.
Ferric citrate was well-tolerated throughout the OLE study. There were no patient deaths during the OLE and no serious adverse events reported related to ferric citrate.
The investigators concluded that in this OLE trial of ferric citrate with doses as high as 6 g/day, ferric citrate demonstrated the potential to be used long-term as a phosphate binder in ESRD patients. Ferric citrate appeared to be efficacious in controlling serum phosphorus and well-tolerated and safe for up to one year. Additionally, it is the investigators' opinion that this OLE trial, along with data from both animal studies and the Phase 2 high dose trial supports the notion that some iron absorption may be occurring with the use of ferric citrate as a phosphate binder in ESRD patients and that if a reduction in the use of IV-iron supplements and/or EPO are documented in future long-term clinical trials, the cost-benefit and cost-effectiveness of ferric citrate as a phosphate binder, as compared to currently marketed phosphate binders, would be significant.
Ron Bentsur, CEO of Keryx Biopharmaceuticals, commented, "This long-term data provides further evidence of the potential utility of Zerenex as an effective phosphate binder. Also of importance, is Zerenex's potential ability, as an iron-based phosphate binder, to lower the need for IV-iron and/or EPO in this patient population, which could be another advantage, compared to the currently marketed phosphate binders. We intend to monitor for this potential benefit in our upcoming Phase 3 program."
The Company's Phase 3 clinical program of Zerenex as a treatment for hyperphosphatemia in patients with end-stage renal disease who are on dialysis is pending commencement under a Special Protocol Assessment (SPA) agreement with the FDA.
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.
About Keryx Biopharmaceuticals, Inc.
Keryx Biopharmaceuticals is focused on the acquisition, development and commercialization of medically important pharmaceutical products for the treatment of life-threatening diseases, including cancer and renal disease. Keryx is developing KRX-0401 (perifosine), a novel, potentially first-in-class, oral anti-cancer agent that inhibits Akt activation in the phosphoinositide 3-kinase (PI3K) pathway, and also affects a number of other key signal transduction pathways, including the JNK pathway, all of which are pathways associated with programmed cell death, cell growth, cell differentiation and cell survival. KRX-0401 has demonstrated both safety and clinical efficacy in several tumor types, both as a single agent and in combination with novel therapies. KRX-0401 is currently in Phase 3 clinical development for both refractory advanced colorectal cancer and multiple myeloma, and in Phase 2 clinical development for several other tumor types. Each of the KRX-0401 Phase 3 programs are being conducted under Special Protocol Assessment (SPA) agreements with the FDA. Keryx is also developing Zerenex(TM) (ferric citrate), an oral, iron-based compound that has the capacity to bind to phosphate and form non-absorbable complexes. The Phase 3 clinical program of Zerenex in the treatment for hyperphosphatemia (elevated phosphate levels) in patients with end-stage renal disease is pending commencement under an SPA agreement with the FDA. Keryx is headquartered in New York City.
Some of the statements included in this press release, particularly those anticipating future clinical and business prospects for Zerenex (ferric citrate), may be forward-looking statements that involve a number of risks and uncertainties. For those statements, we claim the protection of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995. Among the factors that could cause our actual results to differ materially are the following: our ability to successfully and cost-effectively complete clinical trials for Zerenex; the risk that the data (both safety and efficacy) from the Phase 3 program will not coincide with the data analyses from the Phase 2 clinical trials previously reported by the Company, including the effects on IV iron and erythropoietin use observed in the long-term safety extension trial; and other risk factors identified from time to time in our reports filed with the Securities and Exchange Commission. Any forward-looking statements set forth in this press release speak only as of the date of this press release. We do not intend to update any of these forward-looking statements to reflect events or circumstances that occur after the date hereof. This press release and prior releases are available at http://www.keryx.com. The information in our website is not incorporated by reference into this press release and is included as an inactive textual reference only.
SP (mg/dL) PxC (mg/dL)(2) Baseline (sd) 5.63 (1.22) 50.79 (12.74) 3 months (sd) 5.48 (1.33) 51.84 (12.67) 6 months (sd) 5.16 (1.20) 48.40 (9.60) 9 months (sd) 5.24 (1.20) 48.72 (12.04) 12 months (sd) 5.21 (1.09) 50.05 (11.82) -------------- ---------- ------------
SOURCE Keryx Biopharmaceuticals, Inc.